Just Finished Reading: The Possibility of Life – Searching for Kinship in the Cosmos by Jaime Green (FP: 2023) [276pp] 

As far as we know, life on Earth emerged practically the moment conditions allowed. As soon as the crust was cool enough for liquid water – BAMM Life! That being the case I have long thought it likely (actually very likely) that life is everywhere in the cosmos although, like Brian Cox, I like to restrict myself to our galaxy which is plenty big enough to be getting on with. 

Starting by looking at the origin of life on Earth (still very much open for debate and further study) the author considers exactly what conditions had to exist to facilitate the leap from lifeless to living matter and how this process could have been replicated on other worlds both similar to and different from our own. Interestingly (again as Brian Cox has stated) there are likely to be BILLIONS of Earth-like worlds in the galaxy so, unless the odds for life are vanishing low, we can expect life elsewhere just on the basis of statistics. Although the Earth does seem to have some ‘unusual’ characteristics – a significantly larger moon that we’d expect – personally I don’t think that we’re odd enough to be anywhere like unique. 

Once the foundations are laid, the author moves onwards looking at planet formation (most stars seem to have at least a few planets) and relates what we can glean about other planetary systems orbiting a variety of star types (note: Red Dwarves last a LONG-ass time!). Then its time for the meat... Multicellular life. Whilst its true that for most of Earth’s history we were a world dominated by single cell life personally I don’t think that such a state is the universal default. If cells bunching together happened here – no matter how ‘late’ - I don’t see why it can’t happen elsewhere and possibly a whole lot quicker. Of course, operating with a single example – US! - its difficult to draw any firm conclusions. Hopefully such a state of affairs won’t last forever. Again, personally I’m betting for simple life on Mars and more complex (fish?) under the ice of Jupiter’s moons. Here’s hoping! 

Once you have complex life the next natural question is going to be about intelligence – could we recognise alien creatures as people? I’m not sure about this one. We humans are late arrivals in the grand scheme of things and its possible that we’re an aberration. We might just be alone in that regard. Of course, the other thing – especially if we’re hoping for some kind of communication if not actual hand/tentacle shakes is technology. The ability to send and receive messages over stellar distances is VERY new for us, so we might be checking out planets that haven’t invented radio yet or even have been scanned in the past during the height of the Roman Empire – proving that there are no intelligent beings here! 

Its still (very) early days and there are still lots of questions to be answered (or even posed). From what we know about our planet and our galaxy life SHOULD be reasonably common. Finding it is, of course, a whole other ball game. We haven’t been looking very long and we’re still working out exactly what we need to look for – water worlds, radio waves, mega-structures? - so I’m not particularly let down by the results so far. Jupiter’s moons are our best bet for finding additional life in our Solar system. What would be really nice is if we could establish early on that it emerged and developed completely independently of life on Earth. If life could begin in two places in the same system, then that would indicate that life is EVERYWHERE (crosses fingers). 

The author is obviously enthusiastic about the subject which really comes across. She also uses a LOT of Sci-Fi references – an important source of speculation about alien life – which is why I’ve added the SF label to the list. Such references certainly didn’t hinder my enjoyment of this work. If you’ve ever wondered about the subject and wanted an idea where the latest research and ideas are leading us then this is the book for you. Definitely recommended.

Just Finished Reading: The Zoologist’s Guide to the Galaxy – What Animals on Earth Reveal About Aliens and Ourselves by Dr Arik Kershenbaum (FP: 2020) [324pp] 

It’s a deceptively simple question: What can we say about life beyond Earth in the rest of the Galaxy? The obvious, maybe even the instinctive, answer is: Nothing. We know of life in only one place, here on Earth. We can say, probably, with a fair degree of confidence that there IS life in the Galaxy but what is it like? With billions of planets orbiting billions of stars there must be countless environments where life could emerge, but how can we confidently extrapolate from a single example? We can’t, right? Or maybe, actually we can. 

Hollywood and Science Fiction authors have tried to envisage aliens for us to either fall in love with or have nightmares about. But even a cursory examination, with any scientific background, shows that most of the well-known aliens are nothing more than human life made either large or particularly malevolent. I mean, concentrated acid for blood? Yeah, right. But moving on from Hollywood is easier than you might expect. Until we actually find any and are able to analyse it, we don’t know if alien life will utilise the DNA we’re so familiar with. What we can be more certain about is that, no matter where life emerges, the environment will no doubt have limited resources. Because of this it follows that alien life will need to compete for those resources and that some alien creatures will be more adept at this competition than others. With those simple facts it appears that Evolutionary principles will operate throughout the Galaxy and, indeed, into other Galaxies too. Evolution is something we have a pretty good understanding of, and we can use that understanding to come to some reasonable conclusions about life elsewhere. 

This is the foundation for this fascinating book – that Evolution, as we know it here, operates in the same way out there no matter if aliens use DNA or if they’re carbon based (they’re highly likely to be!) or if their atmosphere is oxygen, methane or something else. From that baseline we can reasonably expect that aliens will move around – swim, fly, walk – and that they’ll be able to gain information about their environment through eyes, ears, whiskers or more exotic ways through magnetic fields. Likewise, they’ll be about to communicate through sound, light or in other ways in order to attract mates, ward of danger or even to sing. We may not know exactly what an alien creature might LOOK like, but we can expect things like kin bias, social structures, hierarchies and so much more we are already familiar with. There is indeed a great deal we can say about aliens without (at the moment) ever meeting one. 

This was a fun read for me. Most of my Science reading is in the Biology/Evolution sphere, so it's interesting to link that – not just speculatively – to my other long-term interest in alien life in the Galaxy. Hopefully, with the probe on its way to Jupiter’s moons we might get a good idea if life exists outside Earth and yet still inside our own Solar System. If strong indications of life ARE found that’ll be amazing. I’m a firm believer that life does indeed exist ‘out there’ and will not be in the least surprised if bacteria are found on Mars and that fish swim in the seas under the ice on a few of Jupiter's moons. Definitely a recommended read for anyone interesting in the alien life question.  

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Just Finished Reading: Life Everywhere – The Maverick Science of Astrobiology by David Darling (FP: 2001) [182pp] 

This interesting slim volume was written in response to my previous book on the subject [Rare Earth – Why Complex Life Is Uncommon in the Universe by Peter D Ward and Donald Brownlee] reviewed back in March last year and was, essentially a refutation of its conclusions and many of its underlying assumptions of the so-called special or unique nature of planet Earth where life is concerned. Contrary to the ideas in ‘Rare Earth’ the author here contends that life is common throughout the galaxy and that increased complexity is almost certain based on what we know about life on Earth. Of course, since we’re working with a single example here, extrapolation is difficult but not impossible. Even 20 years ago when this book was published, we had a pretty fair understanding about when and how life emerged on this planet. One thing that really stuck out was that it was QUICK. As far as we can tell the moment life could begin it did. That alone suggests that the start of life is comparatively easy given a reasonable set of starting conditions. What’s more, now we know about the number and range of extremophiles living quite happily in environments thought to be hostile to life, those conditions seem to be a lot wider and less benign than we first thought.  

So, we can say with a fair degree of confidence that, where a wide range of conditions allow, life will emerge quickly. Once life has emerged it will grow, expand and evolve. Part of that evolutionary process is to adapt to the local conditions and also quite naturally slowly increase in complexity. Earth in this sense cannot be unique. Contentions that for life to exist or evolve a planet needs a large moon or any other obviously Earth specific attribute is nothing more than special pleading and yet another defensive redoubt to protect the supposedly special place of Earth or (by extension) humanity in the grand scheme of things. With what we know of the Universe this simply won’t stand. 

The author contends (and I agree with him) that the prospect for the longed-for existence of life on Mars is possible – if only just. Life may have emerged independently there (indeed it's possible that life on Earth may have been at least partially seeded from Mars) in its warm wet period and then either become extinct or moved underground. We’ve found some tantilising hints so far but nothing definite at least yet! Much more likely (and I agree again) is the possibility of life under the ice on several of Jupiter’s moons. Knowing what we know of the ‘black smokers’ on our own seabed I think it’s entirely likely that not only bacteria exist in those oceans, but I fully expect our probes to find complex fish. If we do find life – proven as far as possible to have evolved independently of Earth – on any other body in this Solar System, it would indeed indicate that life is everywhere. I do hope so! 

Overall, despite its age, this was an interesting read and a good introduction to the ideas behind Astrobiology and the search for life elsewhere. If the topic intrigues you I can definitely think of worse places to start reading about it. Recommended. More current reading on this topic to come.    

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Just Finished Reading: Rare Earth – Why Complex Life Is Uncommon in the Universe by Peter D Ward and Donald Brownlee (FP: 2000) [287pp] 

Humans have been wondering if we are ‘alone’ in the Universe for a long time – centuries at least if not longer. Only in the last 20 years or so, and mostly after the publication of this book, are we starting to get enough data together to start answering that question. The biggest impact on our understanding of the possibility of life elsewhere is the large and ever-growing number of planets already discovered with more coming in each day. With the launch and activation of the new James Webb telescope I imagine that these numbers will skyrocket. But not so fast, say the authors! Just because we’re finding planets doesn’t mean that we’ll find life and especially complex life. It’s really not that simple. For example, of the 8 (or 9 if you still count Pluto) planets in our system only 1 can definitely be shown to have complex life. If most star systems are like ours – which we suspect they’re not – then the odds are greatly reduced. Furthermore, as the authors point out, a good part of our galaxy might be life fee, or at least complex life free, because of the real danger of nearby stellar explosions and other cosmic threats. Not only do stars have habitable or ‘Goldilocks’ zones but so do galaxies. The authors even dismiss whole galaxies (of the ‘wrong’ type) likely to be unlikely candidates for life. So, are we alone? Is Earth a rare and precious example or are the authors being far too pessimistic? 

I knew going into this book that I’d have problems with the author’s conclusions. I am of the belief, and it is a belief, that life is common is our galaxy (I’m not going to discuss the universe as a whole because we’ll never explore the vast majority of it unless we can develop some very exotic propulsion systems). Surprisingly though, the authors agree that at least bacteria are indeed common throughout the cosmos. Although we presently only have a single example to work from – our home planet Earth – it appears certain that life emerged here almost as soon as it could and has been present ever since for around 3.7 to 4 billion years. Most of that time bacteria has been the only life present and it still makes up the vast majority of biomass on the planet. Bacteria is, and always has been a dominant lifeform. Reasonably extrapolating from our one example its probable that bacteria will exist on every world capable of supporting it. Where we disagree is what comes next. The authors argue (or just as often simply declare) that anything much more complex than bacteria has a much harder job of developing and thriving and, therefore, will be vanishingly rare. Generally, I found their arguments to support this conclusion (something that often felt already decided upon) varied between weak and disingenuous. Some had merit – the stability of various star types for example – but in every case they took doubts as fact and foibles as necessities – that planets with complex life demand large satellites, at least one Jupiter in the system to mop up potential planet killers and a whole host of other ‘reasons’ for Earth being close to unique. In each and every category their argument always managed to get the ‘benefit of the doubt’ even if that ‘doubt’ had to be manufactured in advance. Indeed, much was made of the fact that at publication date no Earth type planets had yet been discovered – despite the fact that the authors knew full well that technology of the time could not detect planets that small!  

I am of the opinion that, wherever conditions allow, life will emerge on planets throughout the galaxy. If time permits that life, certainly at the level of bacteria, will spread and become ‘endemic’ and almost impossible to remove with anything less than a truly planet shattering cataclysmic event. Once life is so established I think, in line with my reading of Stephen J Gould, it will inevitably increase in complexity for the simple reason that life at such a basic level will find it difficult to become less complex. Random mutations will, over time if conditions are reasonably stable, gradually and inevitably increase life’s complexity. Just how complex life will then become is anyone’s guess. Again, given enough time and reasonable levels of environmental stability, I see no reason why complexity cannot steadily increase. Will this produce intelligent life that we could converse with? Possibly. Again, we don’t know enough about how intelligence (what we have anyway!) emerged on the one planetary example we have. Intelligence and self-awareness might be a one in a million fluke, or it might be just a matter of time. We don’t know but I certainly don’t dismiss the possibility. Like the famous ‘Drake Equation’ the author’s produced an equation of their own. I’ve seen people plug in the most pessimistic figures into each function and the number they came up with is 10 – that 9 other human level civilisations in our galaxy right now. Personally, I think that number is way too low. Carl Sagan suggested that there could be 1000’s of civilisations out there, but I think that figure is probably too optimistic. Despite the fact that we haven’t been looking very long I think we might have stumbled upon at least 1 of them by now! I think the realistic figure is probably in the 100’s. Some will be less advanced than us (if that’s possible!) and others will be much more advanced. The galaxy is, however, on the large side so it’s entirely possible that our nearest intelligent neighbour might simply be too far away for us to notice each other. 

Looking within our own system we have, obviously, one strong example of complex life but are there any others close at hand? Personally, I wouldn’t be hugely surprised (though undoubtedly delighted) if we eventually find independently evolved bacteria in caves on Mars. The planet was wet for a while and it just might have been hospitable enough for long enough for life to emerge. As conditions worsened and life struggled to survive it would have moved underground. Complex, but still reasonably simple, life might be a possibility but bacteria are, I think, a distinct probability. If the suspected deep oceans of liquid water exist on some of Jupiter’s moons, then the odds of complex life there increase greatly. Again, personally I wouldn’t be in the least surprised if our first probes report fish happily swimming around in the pitch black beneath kilometers of ice. Overall, this book was pretty much what I expected so I wasn’t particularly disappointed that I disagreed with most of what the author’s proposed. It’s worth a read despite being 20 years out of date as well as being unduly pessimistic (trying vainly to retain *some* special place for humanity after so many demotions I think). Two more positive books on this subject to come later in the year. Reasonable. 

Astronomers want public funds for intelligent life search

By Pallab Ghosh for BBC News

15 February 2020

The head of one of the US's national observatories says the search for intelligent life elsewhere in the universe needs to be taken more seriously. Dr Anthony Beasley told the BBC that there should be greater government support for a field that has been shunned by government research funders for decades. His backing for the search for extra-terrestrial intelligence (Seti) marks a sea change in attitudes to a field regarded until recently as fringe science. Dr Beasley made his comments at the American Association for the Advancement of Science meeting in Seattle. The director of the US National Radio Astronomy Observatory in Charlottesville in Virginia said that it was now "time for Seti to come in from the cold and be properly integrated to all other areas of astronomy".

Dr Beasley's comments come as one of the private sector funders of Seti research announced that the Very Large Array (VLA) observatory in New Mexico would be joining the effort to detect signs of intelligent life on other worlds. The VLA is a multi-antenna observatory and home to what is regarded as one of the best-equipped telescopes in the world. According to Dr Andrew Siemion, leader of the Breakthrough Listen science team at the University of California, Berkeley's Seti Research Centre, the incorporation of the VLA would increase the chances of finding intelligent life by "10- or even 100-fold". "We are now set for the most comprehensive all-sky survey [for extra-terrestrial intelligence] that has ever been accomplished," he told the BBC. Equally important, according to Dr Siemion, is the credibility that the VLA's involvement brings to the field. "We would like to see Seti transformed from a small cabal of scientists and engineers in California, isolated from academia to one that is as much an integral part of astronomy and astrophysics as any other field of inquiry." Breakthrough Listen is a privately funded project to search for intelligent extra-terrestrial communications throughout the universe. The 10-year project began in 2016, funded by the billionaire Yuri Milner to the tune of $100m (£77m).

The UK's Astronomer Royal, Professor Lord Rees, is the chair of the organisation's international advisory group. He told the BBC that, given that the multi-billion pound Large Hadron Collider had not yet achieved its aim of finding sub-atomic particles beyond the current theory of physics, governments should consider modest funding of a few million pounds for Seti. "I'd feel far more confident arguing the case for Seti than for a particle accelerator," he said. "Seti searches are surely worthwhile, despite the heavy odds against success, because the stakes are so high". Nasa once funded the search for extra-terrestrial intelligence to the tune of $10m a year. But the funding was scrapped in 1993 following the introduction of legislation by Senator Richard Bryan, who believed it to be a waste of money. "This hopefully will be the end to the Martian hunting season at the taxpayer's expense," he said at the time. There has been no significant public funding for Seti in the US or anywhere else in the world since, although so-called astrobiology searches for evidence of simple organisms from the chemical signatures in the atmosphere's of other worlds receives increasing backing. At the time, the first few planets orbiting distant stars were discovered, but it was not known if this was the norm. We now know that it is - nearly 4,000 have been discovered to date. It is this development, according to Dr Siemion, that has persuaded many respected scientists that the search for intelligent life on other worlds should be taken more seriously. "Ever since human beings have looked up at the night sky and wondered 'is there anyone out there?' We now have the capacity to answer that question, and perhaps to make a discovery that would rank as the most profound scientific discoveries in the history of humanity".

[It’s amazing just how little is being spent on SETI right now. A truly TINY amount of money compared to other projects. As has been shown with finding planets – the more you look the more you find. Answering one of THE fundamental questions might be a few million dollars away. The odds might be long, although I for one don’t think the odds are THAT long as to make it not worth our while looking, but finding evidence of life elsewhere would essentially change EVERYTHING. Worth a few hundred mill off the top I think…..]

Rosetta’s comet contains ingredients for life

From ESA

27/05/2016

Ingredients regarded as crucial for the origin of life on Earth have been discovered at the comet that ESA’s Rosetta spacecraft has been probing for almost two years. They include the amino acid glycine, which is commonly found in proteins, and phosphorus, a key component of DNA and cell membranes. Scientists have long debated the important possibility that water and organic molecules were brought by asteroids and comets to the young Earth after it cooled following its formation, providing some of the key building blocks for the emergence of life.

While some comets and asteroids are already known to have water with a composition like that of Earth’s oceans, Rosetta found a significant difference at its comet – fuelling the debate on their role in the origin of Earth’s water. But new results reveal that comets nevertheless had the potential to deliver ingredients critical to establish life as we know it. Amino acids are biologically important organic compounds containing carbon, oxygen, hydrogen and nitrogen, and form the basis of proteins.

Hints of the simplest amino acid, glycine, were found in samples returned to Earth in 2006 from Comet Wild-2 by NASA’s Stardust mission. However, possible terrestrial contamination of the dust samples made the analysis extremely difficult. Now, Rosetta has made direct, repeated detections of glycine in the fuzzy atmosphere or ‘coma’ of its comet. “This is the first unambiguous detection of glycine at a comet,” says Kathrin Altwegg, principal investigator of the ROSINA instrument that made the measurements, and lead author of the paper published in Science Advances today. “At the same time, we also detected certain other organic molecules that can be precursors to glycine, hinting at the possible ways in which it may have formed.” The measurements were made before the comet reached its closest point to the Sun – perihelion – in August 2015 in its 6.5 year orbit.

The first detection was made in October 2014 while Rosetta was just 10 km from the comet. The next occasion was during a flyby in March 2015, when it was 30–15 km from the nucleus. Glycine was also seen on other occasions associated with outbursts from the comet in the month leading up to perihelion, when Rosetta was more than 200 km from the nucleus but surrounded by a lot of dust. “We see a strong link between glycine and dust, suggesting that it is probably released perhaps with other volatiles from the icy mantles of the dust grains once they have warmed up in the coma,” says Kathrin. Glycine turns into gas only when it reaches temperatures just below 150°C, meaning that usually little is released from the comet’s surface or subsurface because of the low temperatures. This accounts for the fact that Rosetta does not always detect it.

“Glycine is the only amino acid that is known to be able to form without liquid water, and the fact we see it with the precursor molecules and dust suggests it is formed within interstellar icy dust grains or by the ultraviolet irradiation of ice, before becoming bound up and conserved in the comet for billions of years,” adds Kathrin. Another exciting detection made by Rosetta and described in the paper is of phosphorus, a key element in all known living organisms. For example, it is found in the structural framework of DNA and in cell membranes, and it is used in transporting chemical energy within cells for metabolism. “There is still a lot of uncertainty regarding the chemistry on early Earth and there is of course a huge evolutionary gap to fill between the delivery of these ingredients via cometary impacts and life taking hold,” says co-author Hervé Cottin.

“But the important point is that comets have not really changed in 4.5 billion years: they grant us direct access to some of the ingredients that likely ended up in the prebiotic soup that eventually resulted in the origin of life on Earth. The multitude of organic molecules already identified by Rosetta, now joined by the exciting confirmation of fundamental ingredients like glycine and phosphorous, confirms our idea that comets have the potential to deliver key molecules for prebiotic chemistry,” says Matt Taylor, ESA’s Rosetta project scientist. “Demonstrating that comets are reservoirs of primitive material in the Solar System and vessels that could have transported these vital ingredients to Earth, is one of the key goals of the Rosetta mission, and we are delighted with this result.”

[I know that there has been much speculation of where the original complex chemicals came from that started life on Earth. It’s possible that at least some of them might have come from comets – as long as they survived getting through the atmosphere – but I don’t think that’s where life originated. The way I see it it’s a matter of quantities. The amount of amino acids from space is probably miniscule in the grand scheme of things. I think that most if not all the chemical basis for life originated on Earth – and by extension the chemicals for life on other worlds originated there too. But it’s good to know that complex chemicals can be formed outside of a planetary environment. That indicates to me that such things are extremely common in the galaxy and, by extension, so is life itself.]

Exoplanet tally set to pass 4,000 mark

By Paul Rincon, Science editor, BBC News

23rd March 2019

The number of planets detected around other stars - or exoplanets - is set to hit the 4,000 mark. The huge haul is a sign of the explosion of findings from searches with telescopes on the ground and in space over the last 25 years. It's also an indication of just how common planets are - with most stars in the Milky Way hosting at least one world in orbit around them. That's something astronomers couldn't be certain of just 30 years ago. The Extrasolar Planets Encyclopedia, run by the Observatoire de Paris, has already passed the 4,000 mark. Dr Françoise Roques, from the observatory, who is on the scientific board of the encyclopedia, told BBC News: "The great news is that we shift from a starry sky to a planetary sky, as there are more planets than stars. And also that the planetary systems have great diversity of structure, with planets orbiting zero, one, two... stars, or other planets." The Nasa Exoplanet Archive is 74 planets away from the milestone. But there are 443 planet candidates detected by Nasa's Tess space telescope (launched in 2018) awaiting confirmation. There are a further 2,423 candidates detected by the Kepler space telescope. The latest exoplanet to be added to the Nasa archive was the Super Earth GI 686 b, which orbits a red dwarf star (a type cooler than our Sun) which was discovered using ground telescopes. It was added on 21 March. The total number of confirmed planets differs between the two catalogues because of slightly different acceptance criteria - along with other factors.

The early technique of detecting new worlds by the "wobble" induced by a planet's gravitational tug on its star yielded many giant planets known as "hot Jupiters", which orbited close to their stars. These planet types were easier to detect using the wobble method. Nasa's Kepler space telescope was launched in 2009; it used a different technique known as the transit method to measure the dip in brightness as a planet passed in front of its host star. Kepler discovered hundreds of Neptune-sized planets and those that fell into a category known as Super Earths (those having a mass larger than Earth's but below those of Neptune-sized planets). Dr Roques said it remained a difficult task to distinguish between a type of star known as a brown dwarf and giant planets. "Four-thousand is just a number as the frontier of the planet domain is uncertain," she said. "The brown dwarfs have been defined by the [IAU - International Astronomical Union] as small stars, but in fact, some of them are big planets. Our database collects objects until 60 Jupiter masses and contains a mix of the planetary brown dwarfs (formed in a protoplanetary disk around a star) and starry brown dwarfs (formed by collapse of interstellar cloud). The only way to ensure the difference is to access its internal structure, which is a difficult/ impossible task."

The first exoplanets were found around a pulsar - a highly magnetised neutron star - in 1992 by Aleksander Wolszczan and Dale Frail. The initial discovery of a planet around a main sequence star - those that fuse hydrogen into helium within their cores - was made in 1995 by astronomers Didier Queloz and Michel Mayor. Dr Roque explained: "For the field of exoplanet exploration, we [are going] from discovery projects to exploration projects, for a better understanding of the structure, formation, atmosphere and, of course habitability of exoplanets."

[“There are more planets than stars”…… OK. That’s OFFICALLY mind-blowing. Just look up at a clear night sky and think about that for a few seconds. Every point of light you see probably has at least one planet orbiting around it…. And probably more than one. That’s a LOT of planets out there. The odds of them ALL being lifeless barren rocks, ice planets or gas giants? Not good I’m thinking. Some of them, and probably a lot of them, MUST have life of some sort…. Surely!]

Mysterious radio signals from deep space detected

By Helen Briggs for BBC News

9 January 2019

Astronomers have revealed details of mysterious signals emanating from a distant galaxy, picked up by a telescope in Canada. The precise nature and origin of the blasts of radio waves is unknown. Among the 13 fast radio bursts, known as FRBs, was a very unusual repeating signal, coming from the same source about 1.5 billion light years away. Such an event has only been reported once before, by a different telescope. "Knowing that there is another suggests that there could be more out there," said Ingrid Stairs, an astrophysicist from the University of British Columbia (UBC). "And with more repeaters and more sources available for study, we may be able to understand these cosmic puzzles - where they're from and what causes them." The CHIME observatory, located in British Columbia's Okanagan Valley, consists of four 100-metre-long, semi-cylindrical antennas, which scan the entire northern sky each day. The telescope only got up and running last year, detecting 13 of the radio bursts almost immediately, including the repeater.

The research has now been published in the journal Nature. "We have discovered a second repeater and its properties are very similar to the first repeater," said Shriharsh Tendulkar of McGill University, Canada. "This tells us more about the properties of repeaters as a population." FRBs are short, bright flashes of radio waves, which appear to be coming from almost halfway across the Universe. So far, scientists have detected about 60 single fast radio bursts and two that repeat. They believe there could be as many as a thousand FRBs in the sky every day. There are a number of theories about what could be causing them. They include a neutron star with a very strong magnetic field that is spinning very rapidly, two neutron stars merging together, and, among a minority of observers, some form of alien spaceship.

[There is much we still don’t know about our Universe. So it’s highly likely that these ‘signals’ are of completely natural origin. However, it’s fun to speculate that they could be ‘warp signatures’ as alien spaceships jump to FTL flight or they are the results of a space battle over a billion light years away! But in the end it’s probably just an odd Neutron star effect of a Black Hole collapsing or something equally ‘mundane’….. No doubt we will find out soon enough.]

NASA Confirms Evidence That Liquid Water Flows on Today’s Mars

From NASA

September 28, 2015

New findings from NASA's Mars Reconnaissance Orbiter (MRO) provide the strongest evidence yet that liquid water flows intermittently on present-day Mars.

Using an imaging spectrometer on MRO, researchers detected signatures of hydrated minerals on slopes where mysterious streaks are seen on the Red Planet. These darkish streaks appear to ebb and flow over time. They darken and appear to flow down steep slopes during warm seasons, and then fade in cooler seasons. They appear in several locations on Mars when temperatures are above minus 10 degrees Fahrenheit (minus 23 Celsius), and disappear at colder times.

“Our quest on Mars has been to ‘follow the water,’ in our search for life in the universe, and now we have convincing science that validates what we’ve long suspected,” said John Grunsfeld, astronaut and associate administrator of NASA’s Science Mission Directorate in Washington. “This is a significant development, as it appears to confirm that water -- albeit briny -- is flowing today on the surface of Mars.”

These downhill flows, known as recurring slope lineae (RSL), often have been described as possibly related to liquid water. The new findings of hydrated salts on the slopes point to what that relationship may be to these dark features. The hydrated salts would lower the freezing point of a liquid brine, just as salt on roads here on Earth causes ice and snow to melt more rapidly. Scientists say it’s likely a shallow subsurface flow, with enough water wicking to the surface to explain the darkening.

"We found the hydrated salts only when the seasonal features were widest, which suggests that either the dark streaks themselves or a process that forms them is the source of the hydration. In either case, the detection of hydrated salts on these slopes means that water plays a vital role in the formation of these streaks," said Lujendra Ojha of the Georgia Institute of Technology (Georgia Tech) in Atlanta, lead author of a report on these findings published Sept. 28 by Nature Geoscience.

Ojha first noticed these puzzling features as a University of Arizona undergraduate student in 2010, using images from the MRO's High Resolution Imaging Science Experiment (HiRISE). HiRISE observations now have documented RSL at dozens of sites on Mars. The new study pairs HiRISE observations with mineral mapping by MRO’s Compact Reconnaissance Imaging Spectrometer for Mars (CRISM). The spectrometer observations show signatures of hydrated salts at multiple RSL locations, but only when the dark features were relatively wide. When the researchers looked at the same locations and RSL weren't as extensive, they detected no hydrated salt. 

Ojha and his co-authors interpret the spectral signatures as caused by hydrated minerals called perchlorates. The hydrated salts most consistent with the chemical signatures are likely a mixture of magnesium perchlorate, magnesium chlorate and sodium perchlorate. Some perchlorates have been shown to keep liquids from freezing even when conditions are as cold as minus 94 degrees Fahrenheit (minus 70 Celsius). On Earth, naturally produced perchlorates are concentrated in deserts, and some types of perchlorates can be used as rocket propellant.

Perchlorates have previously been seen on Mars. NASA's Phoenix lander and Curiosity rover both found them in the planet's soil, and some scientists believe that the Viking missions in the 1970s measured signatures of these salts. However, this study of RSL detected perchlorates, now in hydrated form, in different areas than those explored by the landers. This also is the first time perchlorates have been identified from orbit. MRO has been examining Mars since 2006 with its six science instruments.

"The ability of MRO to observe for multiple Mars years with a payload able to see the fine detail of these features has enabled findings such as these: first identifying the puzzling seasonal streaks and now making a big step towards explaining what they are," said Rich Zurek, MRO project scientist at NASA's Jet Propulsion Laboratory (JPL) in Pasadena, California.

For Ojha, the new findings are more proof that the mysterious lines he first saw darkening Martian slopes five years ago are, indeed, present-day water.

"When most people talk about water on Mars, they're usually talking about ancient water or frozen water," he said. "Now we know there’s more to the story. This is the first spectral detection that unambiguously supports our liquid water-formation hypotheses for RSL."

The discovery is the latest of many breakthroughs by NASA’s Mars missions.

“It took multiple spacecraft over several years to solve this mystery, and now we know there is liquid water on the surface of this cold, desert planet,” said Michael Meyer, lead scientist for NASA’s Mars Exploration Program at the agency’s headquarters in Washington. “It seems that the more we study Mars, the more we learn how life could be supported and where there are resources to support life in the future.”

There are eight co-authors of the Nature Geoscience paper, including Mary Beth Wilhelm at NASA’s Ames Research Center in Moffett Field, California and Georgia Tech; CRISM Principal Investigator Scott Murchie of the Johns Hopkins University Applied Physics Laboratory in Laurel, Maryland; and HiRISE Principal Investigator Alfred McEwen of the University of Arizona Lunar and Planetary Laboratory in Tucson, Arizona. Others are at Georgia Tech, the Southwest Research Institute in Boulder, Colorado, and Laboratoire de Planétologie et Géodynamique in Nantes, France.

[I know I keep banging on about this, intermittently anyway, but if water is flowing on Mars even seasonally and has been for some time then I think there’s decent odds that they’ll discover life of some kind their eventually. It’s a fairly big planet with around the same surface area as Earth I think (we have oceans too which naturally makes possible biomes much more available for life than on Mars!) so the only way we’re going to stumble across it presently is by accident. But just imagine what it will mean when/if they do find it!]

NASA Finds Ancient Organic Material, Mysterious Methane on Mars

From NASA

June 07, 2018

NASA’s Curiosity rover has found new evidence preserved in rocks on Mars that suggests the planet could have supported ancient life, as well as new evidence in the Martian atmosphere that relates to the search for current life on the Red Planet. While not necessarily evidence of life itself, these findings are a good sign for future missions exploring the planet’s surface and subsurface. The new findings – “tough” organic molecules in three-billion-year-old sedimentary rocks near the surface, as well as seasonal variations in the levels of methane in the atmosphere – appear in the June 8 edition of the journal Science.

Organic molecules contain carbon and hydrogen, and also may include oxygen, nitrogen and other elements. While commonly associated with life, organic molecules also can be created by non-biological processes and are not necessarily indicators of life.  “With these new findings, Mars is telling us to stay the course and keep searching for evidence of life,” said Thomas Zurbuchen, associate administrator for the Science Mission Directorate at NASA Headquarters, in Washington. “I’m confident that our ongoing and planned missions will unlock even more breathtaking discoveries on the Red Planet.”

“Curiosity has not determined the source of the organic molecules,” said Jen Eigenbrode of NASA’s Goddard Space Flight Center in Greenbelt, Maryland, who is lead author of one of the two new Science papers. “Whether it holds a record of ancient life, was food for life, or has existed in the absence of life, organic matter in Martian materials holds chemical clues to planetary conditions and processes.” Although the surface of Mars is inhospitable today, there is clear evidence that in the distant past, the Martian climate allowed liquid water – an essential ingredient for life as we know it – to pool at the surface. Data from Curiosity reveal that billions of years ago, a water lake inside Gale Crater held all the ingredients necessary for life, including chemical building blocks and energy sources.

“The Martian surface is exposed to radiation from space. Both radiation and harsh chemicals break down organic matter,” said Eigenbrode. “Finding ancient organic molecules in the top five centimeters of rock that was deposited when Mars may have been habitable, bodes well for us to learn the story of organic molecules on Mars with future missions that will drill deeper.” In the second paper, scientists describe the discovery of seasonal variations in methane in the Martian atmosphere over the course of nearly three Mars years, which is almost six Earth years. This variation was detected by Curiosity’s Sample Analysis at Mars (SAM) instrument suite.

Water-rock chemistry might have generated the methane, but scientists cannot rule out the possibility of biological origins. Methane previously had been detected in Mars' atmosphere in large, unpredictable plumes. This new result shows that low levels of methane within Gale Crater repeatedly peak in warm, summer months and drop in the winter every year. "This is the first time we've seen something repeatable in the methane story, so it offers us a handle in understanding it," said Chris Webster of NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, California, lead author of the second paper. "This is all possible because of Curiosity's longevity. The long duration has allowed us to see the patterns in this seasonal 'breathing.'"

To identify organic material in the Martian soil, Curiosity drilled into sedimentary rocks known as mudstone from four areas in Gale Crater. This mudstone gradually formed billions of years ago from silt that accumulated at the bottom of the ancient lake. The rock samples were analyzed by SAM, which uses an oven to heat the samples (in excess of 900 degrees Fahrenheit, or 500 degrees Celsius) to release organic molecules from the powdered rock. SAM measured small organic molecules that came off the mudstone sample – fragments of larger organic molecules that don’t vaporize easily. Some of these fragments contain sulfur, which could have helped preserve them in the same way sulfur is used to make car tires more durable, according to Eigenbrode.

The results also indicate organic carbon concentrations on the order of 10 parts per million or more. This is close to the amount observed in Martian meteorites and about 100 times greater than prior detections of organic carbon on Mars’ surface. Some of the molecules identified include thiophenes, benzene, toluene, and small carbon chains, such as propane or butene. In 2013, SAM detected some organic molecules containing chlorine in rocks at the deepest point in the crater. This new discovery builds on the inventory of molecules detected in the ancient lake sediments on Mars and helps explains why they were preserved.

Finding methane in the atmosphere and ancient carbon preserved on the surface gives scientists confidence that NASA's Mars 2020 rover and ESA’s (European Space Agency's) ExoMars rover will find even more organics, both on the surface and in the shallow subsurface. These results also inform scientists’ decisions as they work to find answers to questions concerning the possibility of life on Mars. “Are there signs of life on Mars?” said Michael Meyer, lead scientist for NASA's Mars Exploration Program, at NASA Headquarters. “We don’t know, but these results tell us we are on the right track.”

[Despite all of the obvious issues (and those we’ve hardly considered) I still have high hopes that life will eventually be found on Mars. Likely to exist underground – maybe in caves where it’s much warmer, sheltered from dangerous surface conditions and, more importantly, possibly wet – it might even consist of primitive multi-cellular life forms. I doubt very much if we could hold a conversation with it but I expect it will be visible to the naked eye. At least I hope so!]

Light shed on mystery space radio pulses

By Paul Rincon for BBC News

10 January 2018

Astronomers have fresh insight on a mysterious source of recurring radio pulses from space. Fast radio bursts (FRB) are one of the most persistent puzzles in astronomy. While usually short-lived, one source in the sky was sending out repeated flashes. Now, a team says the emission may be caused by a dead star located in a very powerful magnetic environment. Details were reported here at the 231st American Astronomical Society meeting. The first FRB was discovered in 2007, in archived data from the Parkes Radio Telescope in Australia. Astronomers were searching for new examples of magnetised neutron stars called pulsars, but found a new phenomenon - a radio burst from 2001. Since then, 18 FRBs - also referred to as "flashes" or "sizzles" - have been found in total. The mystery surrounding their nature has spawned a variety of different possible explanations, from black holes to extra-terrestrial intelligence. Only one of these sources of radio energy has erupted more than once - a so-called burster catalogued as FRB 121102. This FRB has sent out around 150 flashes since its discovery in 2012. Now, in the journal Nature, a team of scientists explains how the emission might come from a neutron star, perhaps one near a black hole or one embedded in a nebula.

The researchers found something interesting about the polarisation of the radio waves - which describes the direction in which they vibrate. When polarised radio waves pass through a region with a magnetic field, the polarisation gets "twisted" by an effect known as Faraday rotation. And the stronger the magnetic field, the greater the twisting. "The only sources in the Milky Way that are twisted as much as FRB121102 are in the galactic centre, which is a dynamic region near a massive black hole. Maybe FRB121102 is in a similar environment in its host galaxy," said Daniele Michilli, a co-author from the University of Amsterdam. "However, the twisting of the radio bursts could also be explained if the source is located in a powerful nebula or supernova remnant," he added. Vishal Gajjar, from the Breakthrough Listen project and the Berkeley SETI Research Center, commented: "At this point, we don't really know the mechanism. There are many questions, such as, how can a rotating neutron star produce the high amount of energy typical of an FRB?" The team used the Arecibo radio observatory in Puerto Rico and the Green Bank telescope in West Virginia to probe the source at higher frequencies than ever before.

Andrew Seymour, a staff astronomer at the Arecibo Observatory, said: "The polarisation properties and shapes of these bursts are similar to radio emission from young, energetic neutron stars in our galaxy. This provides support to the models that the radio bursts are produced by a neutron star." A year ago, the research team pinpointed the location of FRB121102 and reported that it lies in a star-forming region of a dwarf galaxy at a distance of more than three billion light-years from Earth. The enormous distance to the source implies that it releases a monstrous amount of energy in each burst - roughly as much energy in a single burst of one millisecond as the Sun releases in an entire day.

[The Universe is indeed a very strange place and chocked full of strange phenomena like this. I’d never heard of FRB’s until today. They are truly bizarre events. I can see why some people immediately jumped on the ET bandwagon. But if they are natural phenomena as suggested at least we still have hope that at some point in the future they’ll pick up a message or a warp signature or something and we’ll finally know we’re not alone…. At least we can hope….. [grin]]

Saturn moon 'able to support life'

By Jonathan Amos BBC Science Correspondent

13 April 2017

Saturn's ice-crusted moon Enceladus may now be the single best place to go to look for life beyond Earth. The assessment comes on the heels of new observations at the 500km-wide world made by the Cassini probe. It has flown through and sampled the waters from a subsurface ocean that is being jetted into space. Cassini’s chemistry analysis strongly suggests the Enceladean seafloor has hot fluid vents - places that on Earth are known to teem with life. To be clear: the existence of such hydrothermal systems is not a guarantee that organisms are present on the little moon; its environment may still be sterile. But the new results make a compelling case to return to this world with more sophisticated instrumentation - technologies that can re-sample the ejected water for clear evidence that biology is also at play.

"We're pretty darn sure that the internal ocean of Enceladus is habitable and we need to go back and investigate it further," said Cassini scientist Dr Hunter Waite from the Southwest Research Institute in San Antonio, Texas. "If there is no life there, why not? And if there is, all the better. But you certainly want to ask the question because it's almost as equally as interesting if there is no life there, given the conditions," he told BBC News.

The sub-surface ocean on Enceladus is thought to be many kilometres deep, kept liquid by the heat generated from the constant gravitational squeezing the moon receives from the mighty Saturn. Cassini has already established that this voluminous liquid is in contact with the rock bed from the types of salts and silica that have also been detected in the jets. But what scientists really wanted to know is if a particular interactive process seen at Earth was taking place in the distant abyss - something called serpentinisation. At the mid-ocean ridges on our planet, seawater is drawn through, and reacts with, hot upwelling rocks that are rich in iron and magnesium. As the minerals in these rocks incorporate H2O molecules into their crystal structure, they release hydrogen - a byproduct that can be used by some microbes as an energy source to drive their metabolism. It is the definitive signal for molecular hydrogen in the plumes of Enceladus that Cassini has now confirmed. "If you were a micro-organism, hydrogen would be like candy - it's your favourite food," explained Dr Chris McKay, an astrobiologist with the US space agency (Nasa). "It's very good energetically; it can support micro-organisms in grand style. Finding hydrogen is certainly a big plus; icing on the cake for the habitability argument, and a very tasty one at that." The type of microbes described by Dr McKay are called methanogens because they make methane as they react the hydrogen with carbon dioxide.

Nasa, which leads the Cassini mission, was due to make the hydrogen announcement a couple of months after the probe's last fly-through of the moon's jets in October 2015. But the agency held off. One of the concerns was that the Ion and Neutral Mass Spectrometer on the satellite can actually make molecular hydrogen inside itself if water enters the instrument in a particular way. Dr Waite's group has spent a year analysing the data to make sure the hydrogen signal is intrinsic to the jets and not merely some artefact of the INMS's operation. And although serpentinisation is arguably the best explanation for the signal, it is possible to produce the gas also from the heating of very primitive (meteoritic) rock. The Cassini mission is coming to a close. Having spent 12 years circling Saturn, it is now running low on fuel and will be dumped in the atmosphere of the ringed planet in September - to ensure it cannot collide with Enceladus at some future date and contaminate it.

As brilliant as the probe's instruments are, they were never designed to make a direct life detection at the bright white moon. This would need a whole new class of spectrometers. A proposal is being put together to fly them in 2026. Nasa has already green-lit a mission to Europa, an ocean moon of Jupiter. It very likely has serpentinisation going on as well. But its ice shell is very much thicker and it could be that very little of the water escapes to space. The appeal of Enceladus is the ease with which its subsurface can be studied because of the material carried into space by its network of geysers. A probe only needs fly through the emission to make the investigation. "The Cassini mission has really brought Enceladus to the fore in terms of the search for life elsewhere in the Solar System," commented British Cassini scientist Dr Andrew Coates. “The top three now I would say are about equal. There's Mars, which may have had life 3.8 billion years ago when conditions were very different to what they are now. There's Europa, which has a subsurface ocean; and now Enceladus. Those three may have, or had, the right conditions for life." Dr Waite added: “For life, you need liquid water, organics, and the CHNOPS elements (carbon, hydrogen, nitrogen, oxygen, phosphorus, sulphur). OK, we haven't yet measured phosphorus and sulphur at Enceladus. But you also need some kind of metabolic energy source, and the new Cassini results are an important contribution in that regard." A paper describing the work of Dr Waite's group is published in the journal Science.

[From what I’ve read over the past few years Enceladus is THE mostly likely location for life outside Earth. We really need to get back there ASAP and start seriously looking for it. Just imagine if we find life there are it has NO connection to life on Earth. If it can be proved to have evolved independently that would be mind-blowing plus open up the possibility of life on a whole host of worlds previously ignored as unlikely. I think knowing that it worth the price of a small pointless war somewhere, right?]

Kepler telescope discovers 100 Earth-sized planets

By Paul Rincon, Science editor BBC News

10th May 2016

Nasa's Kepler telescope has discovered more than 100 Earth-sized planets orbiting alien stars. It has also detected nine small planets within so-called habitable zones, where conditions are favourable for liquid water - and potentially life. The finds are contained within a catalogue of 1,284 new planets detected by Kepler - which more than doubles the previous tally. Nasa said it was the biggest single announcement of new exoplanets. Space agency scientists discussed the new findings in a teleconference on Tuesday.

Statistical analyses of the expanding sample of worlds help astronomers understand how common planets like our own might be. Dr Natalie Batalha, Kepler mission scientist at Nasa's Ames Research Center in California, said calculations suggested there could be more than 10 billion potentially habitable planets in the Milky Way. "About 24% of the stars harbour potentially habitable planets that are smaller than about 1.6 times the size of the Earth. That's a number that we like because it's below that size that we estimate planets are likely to be rocky," said Dr Batalha. "If you ask yourself where is the next habitable planet likely to be, it's within about 11 light-years, which is very close."

Future observatories such as the James Webb Space Telescope could examine starlight filtered through the atmospheres of exoplanets for potential markers of biology. "The ultimate goal of our search is to detect the light from a habitable exoplanet and analyse that light for gases like water vapour, oxygen, methane and carbon dioxide - gases that might indicate the presence of a biological ecosystem," said Paul Hertz, director of astrophysics at Nasa. Of the telescope's finds to date, the planets Kepler-186f and Kepler-452b are arguably the most Earth-like in terms of properties such as their size, the temperature of their host star and the energy received from their star. Dr Batalha said the new finds Kepler 1638b and Kepler-1229b were intriguing targets in the search for habitable planets.

The Nasa Ames researcher said the Kepler mission was part of a "larger strategic goal of finding evidence of life beyond Earth - knowing whether we're alone or not, to know... how life manifests itself in the galaxy and what is the diversity". She added: "Being able to look up to a point of light and being able to say: 'That star has a living world orbiting it.' I think that's very profound and answers questions about why we're here." Dr Timothy Morton, from Princeton University in New Jersey, said the overwhelming majority of exoplanets found by Kepler fell into the super-Earth (1.2-1.9 times bigger than the radius of Earth) and sub-Neptune sized (1.9-3.1 times bigger than Earth's radius). He noted that planets in this size range had no known analogues in our Solar System.

Scientists used a new statistical technique to validate the 1,284 new exoplanets from a pool of 4,302 targets from Kepler's July 2015 catalogue of planet candidates. The technique involves folded in different types of information about the candidates from simulations, giving the astronomers a reliability score for each potential new world. Candidates with a reliability greater than 99% were designated as "validated planets". The team identified a further 1,327 candidates that are more likely than not to be planets, but do not meet the 99% threshold and will require further study. Kepler employs the transit method to detect planets orbiting other stars. This involves measuring the slight dimming of a star's light when an orbiting planet passes between it and the Earth. The same orbital phenomenon was involved when Mercury passed across the face of the Sun on Monday 9 May.

The Kepler telescope, named after the Renaissance astronomer Johannes Kepler, was launched on 7 March 2009. In May 2013, the second of four reaction wheels - used to control a spacecraft's orientation - failed on Kepler. This robbed the orbiting observatory of its ability to stay pointed at a target without drifting off course. However, engineers came up with an innovative solution: using the pressure of sunlight to stabilise the spacecraft, allowing it to continue its planet hunt. The resulting mission was dubbed K2.

[So, there’s a 10 billion to one chance that we’re the only habited planet in the Galaxy. That’s rather long. I suggest just on that calculation alone we’re not the only one….]

Planetary Scientists Find Meteoritic Evidence of Mars Water Reservoir 

From NASA

December 18, 2014

Recent research provides evidence for the existence of a third reservoir that is intermediate in isotopic composition between the Red Planet’s mantle and its current atmosphere. These results support the hypothesis that a buried cryosphere accounts for a large part of the initial water budget of Mars.

NASA and an international team of planetary scientists have found evidence in meteorites on Earth that indicates Mars has a distinct and global reservoir of water or ice near its surface.

Though controversy still surrounds the origin, abundance and history of water on Mars, this discovery helps resolve the question of where the “missing Martian water” may have gone. Scientists continue to study the planet’s historical record, trying to understand the apparent shift from an early wet and warm climate to today’s dry and cool surface conditions.

The reservoir’s existence also may be a key to understanding climate history and the potential for life on Mars. The team’s findings are reported in the journal Earth and Planetary Science Letters.

“There have been hints of a third planetary water reservoir in previous studies of Martian meteorites, but our new data require the existence of a water or ice reservoir that also appears to have exchanged with a diverse set of Martian samples,” said Tomohiro Usui of Tokyo Institute of Technology in Japan, lead author of the paper and a former NASA/Lunar and Planetary Institute postdoctoral fellow. “Until this study there was no direct evidence for this surface reservoir or interaction of it with rocks that have landed on Earth from the surface of Mars.”

Researchers from the Tokyo Institute of Technology, the Lunar and Planetary Institute in Houston, the Carnegie Institution for Science in Washington and NASA’s Astromaterials Research and Exploration Science Division, located at the agency’s Johnson Space Center in Houston, studied three Martian meteorites.

The samples revealed water comprised of hydrogen atoms that have a ratio of isotopes distinct from that found in water in the Red Planet’s mantle and current atmosphere. Isotopes are atoms of the same element with differing numbers of neutrons.

While recent orbiter missions have confirmed the presence of subsurface ice, and melting ground-ice is believed to have formed some geomorphologic features on Mars, this study used meteorites of different ages to show that significant ground water-ice may have existed relatively intact over time.

Researchers emphasize that the distinct hydrogen isotopic signature of the water reservoir must be of sufficient size that it has not reached isotopic equilibrium with the atmosphere.

“The hydrogen isotopic composition of the current atmosphere could be fixed by a quasi-steady-state process that involves rapid loss of hydrogen to space and the sublimation from a widespread ice layer,” said co-author John Jones, a JSC experimental petrologist and member of NASA’s Mars Curiosity rover team.

Curiosity’s observations in a lakebed, in an area called Mount Sharp, indicate Mars lost its water in a gradual process over a significant period of time.

“In the absence of returned samples from Mars, this study emphasizes the importance of finding more Martian meteorites and continuing to study the ones we have with the ever-improving analytical techniques at our disposal,” said co-author Conel Alexander, a cosmochemist at the Carnegie Institution for Science.

In this investigation, scientists compared water, other volatile element concentrations and hydrogen isotopic compositions of glasses within the meteorites, which may have formed as the rocks erupted to the surface of Mars in ancient volcanic activity or by impact events that hit the Martian surface, knocking them off the planet.

“We examined two possibilities, that the signature for the newly identified hydrogen reservoir either reflects near surface ice interbedded with sediment or that it reflects hydrated rock near the top of the Martian crust,” said co-author and JSC cosmochemist Justin Simon. “Both are possible, but the fact that the measurements with higher water concentrations appear uncorrelated with the concentrations of some of the other measured volatile elements, in particular chlorine, suggests the hydrogen reservoir likely existed as ice.”

The information being gathered about Mars from studies on Earth, and data being returned from a fleet of robotic spacecraft and rovers on and around the Red Planet, are paving the way for future human missions on a journey to Mars in the 2030s.

[As much as I admire the time, effort and money that has gone into the very successful probes orbiting Mars as well as those trundling across the surface I still think that we could have a major leap in understanding the Red Planet if we had some people up there. I’m pretty sure that for the cost of a small war or a year’s purchase of pet treats we could have 6-10 scientists based on Mars for a year or so. Just imagine what they might find! Maybe they’d even find life – we’ll never know as long as we depend on robots, no matter how good they are.]

Hubble Finds Three Surprisingly Dry Exoplanets 

From NASA

July 24, 2014

Astronomers using NASA's Hubble Space Telescope have gone looking for water vapor in the atmospheres of three planets orbiting stars similar to the sun -- and have come up nearly dry.

The three planets, known as HD 189733b, HD 209458b, and WASP-12b, are between 60 and 900 light-years away from Earth and were thought to be ideal candidates for detecting water vapor in their atmospheres because of their high temperatures where water turns into a measurable vapor.

These so-called “hot Jupiters” are so close to their star they have temperatures between 1,500 and 4,000 degrees Fahrenheit, however, the planets were found to have only one-tenth to one one-thousandth the amount of water predicted by standard planet-formation theories.

"Our water measurement in one of the planets, HD 209458b, is the highest-precision measurement of any chemical compound in a planet outside our solar system, and we can now say with much greater certainty than ever before that we've found water in an exoplanet," said Nikku Madhusudhan of the Institute of Astronomy at the University of Cambridge, England. "However, the low water abundance we have found so far is quite astonishing."

Madhusudhan, who led the research, said that this finding presents a major challenge to exoplanet theory. "It basically opens a whole can of worms in planet formation. We expected all these planets to have lots of water in them. We have to revisit planet formation and migration models of giant planets, especially “hot Jupiters,” and investigate how they're formed."

He emphasizes that these results may have major implications in the search for water in potentially habitable Earth-sized exoplanets. Instruments on future space telescopes may need to be designed with a higher sensitivity if target planets are drier than predicted. "We should be prepared for much lower water abundances than predicted when looking at super-Earths (rocky planets that are several times the mass of Earth)," Madhusudhan said.

Using near-infrared spectra of the planets observed with Hubble, Madhusudhan and his collaborators estimated the amount of water vapor in each of the planetary atmospheres that explains the data. The planets were selected because they orbit relatively bright stars that provide enough radiation for an infrared-light spectrum to be taken. Absorption features from the water vapor in the planet's atmosphere are detected because they are superimposed on the small amount of starlight that glances through the planet's atmosphere.

Detecting water is almost impossible for transiting planets from the ground because Earth's atmosphere has a lot of water in it, which contaminates the observation. "We really need the Hubble Space Telescope to make such observations," said Nicolas Crouzet of the Dunlap Institute at the University of Toronto and co-author of the study.

The currently accepted theory on how giant planets in our solar system formed, known as core accretion, states a planet is formed around the young star in a protoplanetary disk made primarily of hydrogen, helium, and particles of ices and dust composed of other chemical elements. The dust particles stick to each other, eventually forming larger and larger grains. The gravitational forces of the disk draw in these grains and larger particles until a solid core forms. This then leads to runaway accretion of both solids and gas to eventually form a giant planet.

This theory predicts that the proportions of the different elements in the planet are enhanced relative to those in its star, especially oxygen, which is supposed to be the most enhanced. Once the giant planet forms, its atmospheric oxygen is expected to be largely encompassed within water molecules. The very low levels of water vapor found by this research raise a number of questions about the chemical ingredients that lead to planet formation.

"There are so many things we still don't know about exoplanets, so this opens up a new chapter in understanding how planets and solar systems form," said Drake Deming of the University of Maryland, who led one of the precursor studies. "The problem is that we are assuming the water to be as abundant as in our own solar system. What our study has shown is that water features could be a lot weaker than our expectations."

The findings are published July 24 in The Astrophysical Journal Letters.

[Basic rule of thumb I think – no water, no life. But these are still very much early days in the discovery and understanding of exo-planets. There is much we can do remotely – fortunately given the distances involved and the present impossibility of sending probes outside the Solar System at any reasonable speed or expectation of encountering another world in a reasonable timeframe. But maybe one day in the not too distant future – though long after I’m dead unfortunately – we’ll be any to send remote probes to orbit these worlds and beam back accurate data on the conditions for life that at least some of them will hold.]

The Most Precise Measurement of an Alien World's Size.

From NASA

24th July 2014

Thanks to NASA's Kepler and Spitzer Space Telescopes, scientists have made the most precise measurement ever of the radius of a planet outside our solar system. The size of the exoplanet, dubbed Kepler-93b, is now known to an uncertainty of just 74 miles (119 kilometers) on either side of the planetary body.

The findings confirm Kepler-93b as a "super-Earth" that is about one-and-a-half times the size of our planet. Although super-Earths are common in the galaxy, none exist in our solar system. Exoplanets like Kepler-93b are therefore our only laboratories to study this major class of planet.

With good limits on the sizes and masses of super-Earths, scientists can finally start to theorize about what makes up these weird worlds. Previous measurements, by the Keck Observatory in Hawaii, had put Kepler-93b's mass at about 3.8 times that of Earth. The density of Kepler-93b, derived from its mass and newly obtained radius, indicates the planet is in fact very likely made of iron and rock, like Earth.

"With Kepler and Spitzer, we've captured the most precise measurement to date of an alien planet's size, which is critical for understanding these far-off worlds," said Sarah Ballard, a NASA Carl Sagan Fellow at the University of Washington in Seattle and lead author of a paper on the findings published in the Astrophysical Journal.

"The measurement is so precise that it's literally like being able to measure the height of a six-foot tall person to within three quarters of an inch -- if that person were standing on Jupiter," said Ballard.

Kepler-93b orbits a star located about 300 light-years away, with approximately 90 percent of the sun's mass and radius. The exoplanet's orbital distance -- only about one-sixth that of Mercury's from the sun -- implies a scorching surface temperature around 1,400 degrees Fahrenheit (760 degrees Celsius). Despite its newfound similarities in composition to Earth, Kepler-93b is far too hot for life.

To make the key measurement about this toasty exoplanet's radius, the Kepler and Spitzer telescopes each watched Kepler-93b cross, or transit, the face of its star, eclipsing a tiny portion of starlight. Kepler's unflinching gaze also simultaneously tracked the dimming of the star caused by seismic waves moving within its interior. These readings encode precise information about the star's interior. The team leveraged them to narrowly gauge the star's radius, which is crucial for measuring the planetary radius.

Spitzer, meanwhile, confirmed that the exoplanet's transit looked the same in infrared light as in Kepler's visible-light observations. These corroborating data from Spitzer -- some of which were gathered in a new, precision observing mode -- ruled out the possibility that Kepler's detection of the exoplanet was bogus, or a so-called false positive.

Taken together, the data boast an error bar of just one percent of the radius of Kepler-93b. The measurements mean that the planet, estimated at about 11,700 miles (18,800 kilometers) in diameter, could be bigger or smaller by about 150 miles (240 kilometers), the approximate distance between Washington, D.C., and Philadelphia.

Spitzer racked up a total of seven transits of Kepler-93b between 2010 and 2011. Three of the transits were snapped using a "peak-up" observational technique. In 2011, Spitzer engineers repurposed the spacecraft's peak-up camera, originally used to point the telescope precisely, to control where light lands on individual pixels within Spitzer's infrared camera.

The upshot of this rejiggering: Ballard and her colleagues were able to cut in half the range of uncertainty of the Spitzer measurements of the exoplanet radius, improving the agreement between the Spitzer and Kepler measurements.

"Ballard and her team have made a major scientific advance while demonstrating the power of Spitzer's new approach to exoplanet observations," said Michael Werner, project scientist for the Spitzer Space Telescope at NASA's Jet Propulsion Laboratory, Pasadena, California.

JPL manages the Spitzer Space Telescope mission for NASA's Science Mission Directorate, Washington. Science operations are conducted at the Spitzer Science Center at the California Institute of Technology in Pasadena. Spacecraft operations are based at Lockheed Martin Space Systems Company, Littleton, Colorado. Data are archived at the Infrared Science Archive housed at the Infrared Processing and Analysis Center at Caltech. Caltech manages JPL for NASA.

NASA's Ames Research Center in Moffett Field, California, is responsible for Kepler's ground system development, mission operations and science data analysis. JPL managed Kepler mission development. Ball Aerospace & Technologies Corp. in Boulder, Colorado, developed the Kepler flight system and supports mission operations with the Laboratory for Atmospheric and Space Physics at the University of Colorado in Boulder. The Space Telescope Science Institute in Baltimore archives, hosts and distributes Kepler science data. Kepler is NASA's 10th Discovery Mission and was funded by the agency's Science Mission Directorate.

[Impressive. We’re getting really good at this sort of thing. Now to actually GO to these places!]

New Study Outlines 'Water World' Theory of Life's Origins

From  JPL NASA

April 15, 2014


Life took root more than four billion years ago on our nascent Earth, a wetter and harsher place than now, bathed in sizzling ultraviolet rays. What started out as simple cells ultimately transformed into slime molds, frogs, elephants, humans and the rest of our planet's living kingdoms. How did it all begin?

A new study from researchers at NASA's Jet Propulsion Laboratory in Pasadena, Calif., and the Icy Worlds team at NASA's Astrobiology Institute, based at NASA's Ames Research Center in Moffett Field, Calif., describes how electrical energy naturally produced at the sea floor might have given rise to life. While the scientists had already proposed this hypothesis -- called "submarine alkaline hydrothermal emergence of life" -- the new report assembles decades of field, laboratory and theoretical research into a grand, unified picture.

According to the findings, which also can be thought of as the "water world" theory, life may have begun inside warm, gentle springs on the sea floor, at a time long ago when Earth's oceans churned across the entire planet. This idea of hydrothermal vents as possible places for life's origins was first proposed in 1980 by other researchers, who found them on the sea floor near Cabo San Lucas, Mexico. Called "black smokers," those vents bubble with scalding hot, acidic fluids. In contrast, the vents in the new study -- first hypothesized by scientist Michael Russell of JPL in 1989 -- are gentler, cooler and percolate with alkaline fluids. One such towering complex of these alkaline vents was found serendipitously in the North Atlantic Ocean in 2000, and dubbed the Lost City.

"Life takes advantage of unbalanced states on the planet, which may have been the case billions of years ago at the alkaline hydrothermal vents," said Russell. "Life is the process that resolves these disequilibria." Russell is lead author of the new study, published in the April issue of the journal Astrobiology.

Other theories of life's origins describe ponds, or "soups," of chemicals, pockmarking Earth's battered, rocky surface. In some of those chemical soup models, lightning or ultraviolet light is thought to have fueled life in the ponds.

The water world theory from Russell and his team says that the warm, alkaline hydrothermal vents maintained an unbalanced state with respect to the surrounding ancient, acidic ocean -- one that could have provided so-called free energy to drive the emergence of life. In fact, the vents could have created two chemical imbalances. The first was a proton gradient, where protons -- which are hydrogen ions -- were concentrated more on the outside of the vent's chimneys, also called mineral membranes. The proton gradient could have been tapped for energy -- something our own bodies do all the time in cellular structures called mitochondria.

The second imbalance could have involved an electrical gradient between the hydrothermal fluids and the ocean. Billions of years ago, when Earth was young, its oceans were rich with carbon dioxide. When the carbon dioxide from the ocean and fuels from the vent -- hydrogen and methane -- met across the chimney wall, electrons may have been transferred. These reactions could have produced more complex carbon-containing, or organic compounds -- essential ingredients of life as we know it. Like proton gradients, electron transfer processes occur regularly in mitochondria.

"Within these vents, we have a geological system that already does one aspect of what life does," said Laurie Barge, second author of the study at JPL. "Life lives off proton gradients and the transfer of electrons."

As is the case with all advanced life forms, enzymes are the key to making chemical reactions happen. In our ancient oceans, minerals may have acted like enzymes, interacting with chemicals swimming around and driving reactions. In the water world theory, two different types of mineral "engines" might have lined the walls of the chimney structures.

"These mineral engines may be compared to what's in modern cars," said Russell.
"They make life 'go' like the car engines by consuming fuel and expelling exhaust. DNA and RNA, on the other hand, are more like the car's computers because they guide processes rather than make them happen."

One of the tiny engines is thought to have used a mineral known as green rust, allowing it to take advantage of the proton gradient to produce a phosphate-containing molecule that stores energy. The other engine is thought to have depended on a rare metal called molybdenum. This metal also is at work in our bodies, in a variety of enzymes. It assists with the transfer of two electrons at a time rather than the usual one, which is useful in driving certain key chemical reactions.

"We call molybdenum the Douglas Adams element," said Russell, explaining that the atomic number of molybdenum is 42, which also happens to be the answer to the "ultimate question of life, the universe and everything" in Adams' popular book, "The Hitchhiker's Guide to the Galaxy." Russell joked, "Forty-two may in fact be one answer to the ultimate question of life!"

The team's origins of life theory applies not just to Earth but also to other wet, rocky worlds.

"Michael Russell's theory originated 25 years ago and, in that time, JPL space missions have found strong evidence for liquid water oceans and rocky sea floors on Europa and Enceladus," said Barge. "We have learned much about the history of water on Mars, and soon we may find Earth-like planets around faraway stars. By testing this origin-of-life hypothesis in the lab at JPL, we may explain how life might have arisen on these other places in our solar system or beyond, and also get an idea of how to look for it."

For now, the ultimate question of whether the alkaline hydrothermal vents are the hatcheries of life remains unanswered. Russell says the necessary experiments are jaw-droppingly difficult to design and carry out, but decades later, these are problems he and his team are still happy to tackle.

[Looking good for life – indeed complex life – on Europa and Enceladus. Definitely sitting here with seriously crossed fingers!]

NASA Space Assets Detect Ocean inside Saturn Moon 

From NASA

April 3, 2014

NASA's Cassini spacecraft and Deep Space Network have uncovered evidence Saturn's moon Enceladus harbors a large underground ocean of liquid water, furthering scientific interest in the moon as a potential home to extraterrestrial microbes.

Researchers theorized the presence of an interior reservoir of water in 2005 when Cassini discovered water vapor and ice spewing from vents near the moon's south pole. The new data provide the first geophysical measurements of the internal structure of Enceladus, consistent with the existence of a hidden ocean inside the moon. Findings from the gravity measurements are in the Friday April 4 edition of the journal Science.

"The way we deduce gravity variations is a concept in physics called the Doppler Effect, the same principle used with a speed-measuring radar gun," said Sami Asmar of NASA's Jet Propulsion Laboratory (JPL) in Pasadena, Calif., a coauthor of the paper. "As the spacecraft flies by Enceladus, its velocity is perturbed by an amount that depends on variations in the gravity field that we're trying to measure. We see the change in velocity as a change in radio frequency, received at our ground stations here all the way across the solar system."

The gravity measurements suggest a large, possibly regional, ocean about 6 miles (10 kilometers) deep, beneath an ice shell about 19 to 25 miles (30 to 40 kilometers) thick. The subsurface ocean evidence supports the inclusion of Enceladus among the most likely places in our solar system to host microbial life. Before Cassini reached Saturn in July 2004, no version of that short list included this icy moon, barely 300 miles (500 kilometers) in diameter.

"This then provides one possible story to explain why water is gushing out of these fractures we see at the south pole," said David Stevenson of the California Institute of Technology, Pasadena, one of the paper's co-authors.

Cassini has flown near Enceladus 19 times. Three flybys, from 2010 to 2012, yielded precise trajectory measurements. The gravitational tug of a planetary body, such as Enceladus, alters a spacecraft's flight path. Variations in the gravity field, such as those caused by mountains on the surface or differences in underground composition, can be detected as changes in the spacecraft's velocity, measured from Earth.

The technique of analyzing a radio signal between Cassini and the Deep Space Network can detect changes in velocity as small as less than one foot per hour (90 microns per second). With this precision, the flyby data yielded evidence of a zone inside the southern end of the moon with higher density than other portions of the interior.

The south pole area has a surface depression that causes a dip in the local tug of gravity. However, the magnitude of the dip is less than expected given the size of the depression, leading researchers to conclude the depression's effect is partially offset by a high-density feature in the region, beneath the surface.

"The Cassini gravity measurements show a negative gravity anomaly at the south pole that however is not as large as expected from the deep depression detected by the onboard camera," said the paper's lead author, Luciano Iess of Sapienza University of Rome. "Hence the conclusion that there must be a denser material at depth that compensates the missing mass: very likely liquid water, which is seven percent denser than ice. The magnitude of the anomaly gave us the size of the water reservoir."
There is no certainty the subsurface ocean supplies the water plume spraying out of surface fractures near the south pole of Enceladus, however, scientists reason it is a real possibility. The fractures may lead down to a part of the moon that is tidally heated by the moon's repeated flexing, as it follows an eccentric orbit around Saturn.

Much of the excitement about the Cassini mission's discovery of the Enceladus water plume stems from the possibility that it originates from a wet environment that could be a favorable environment for microbial life.

"Material from Enceladus’ south polar jets contains salty water and organic molecules, the basic chemical ingredients for life," said Linda Spilker, Cassini's project scientist at JPL. "Their discovery expanded our view of the 'habitable zone' within our solar system and in planetary systems of other stars. This new validation that an ocean of water underlies the jets furthers understanding about this intriguing environment."

[Old news but still excellent news. An ocean of any size, and I’m guessing that this one is going to be huge, is a valuable multi-niche environment that has endless possibilities for life. A chemical soup, even under miles of ice, left to its own devices for countless millions of years (most probably) has had plenty of time and opportunity to get very creative. Personally I would be overjoyed if they just found the predicted microbes but I’m guessing that there’s probably much more down there. I don’t see any reason why higher life forms couldn’t have evolved. After all we have the weird and wonderful creatures at the bottom of our own oceans to go by and guide us as to what’s possible in the dark depths. I’d be very surprised if we don’t find actual fish down there. If we found completely alien aquatic animals – completely divorced from anything here on Earth then the possibilities for life on far flung worlds becomes a practical certainty in my mind. Let’s hope that they can get a submersible mission to Enceladus soon and go fishing!]

Kepler Finds a Very Wobbly Planet 

From NASA

February 4, 2014


Imagine living on a planet with seasons so erratic you would hardly know whether to wear Bermuda shorts or a heavy overcoat. That is the situation on a weird, wobbly world found by NASA's planet-hunting Kepler space telescope.

The planet, designated Kepler-413b, precesses, or wobbles, wildly on its spin axis, much like a child's top. The tilt of the planet's spin axis can vary by as much as 30 degrees over 11 years, leading to rapid and erratic changes in seasons. In contrast, Earth's rotational precession is 23.5 degrees over 26,000 years. Researchers are amazed that this far-off planet is precessing on a human timescale.

Kepler 413-b is located 2,300 light-years away in the constellation Cygnus. It circles a close pair of orange and red dwarf stars every 66 days. The planet's orbit around the binary stars appears to wobble, too, because the plane of its orbit is tilted 2.5 degrees with respect to the plane of the star pair's orbit. As seen from Earth, the wobbling orbit moves up and down continuously. Kepler finds planets by noticing the dimming of a star or stars when a planet transits, or travels in front of them. Normally, planets transit like clockwork. Astronomers using Kepler discovered the wobbling when they found an unusual pattern of transiting for Kepler-413b.

"Looking at the Kepler data over the course of 1,500 days, we saw three transits in the first 180 days -- one transit every 66 days -- then we had 800 days with no transits at all. After that, we saw five more transits in a row," said Veselin Kostov, the principal investigator on the observation. Kostov is affiliated with the Space Telescope Science Institute and Johns Hopkins University in Baltimore, Md. The next transit visible from Earth's point of view is not predicted to occur until 2020. This is because the orbit moves up and down, a result of the wobbling, in such a great degree that it sometimes does not transit the stars as viewed from Earth.

Astronomers are still trying to explain why this planet is out of alignment with its stars. There could be other planetary bodies in the system that tilted the orbit. Or, it could be that a third star nearby that is a visual companion may actually be gravitationally bound to the system and exerting an influence. "Presumably there are planets out there like this one that we're not seeing because we're in the unfavorable period," said Peter McCullough, a team member with the Space Telescope Science Institute and Johns Hopkins University. "And that's one of the things that Veselin is researching: Is there a silent majority of things that we're not seeing?"

Even with its changing seasons, Kepler-413b is too warm for life as we know it. Because it orbits so close to the stars, its temperatures are too high for liquid water to exist, making it inhabitable. It also is a super Neptune -- a giant gas planet with a mass about 65 times that of Earth -- so there is no surface on which to stand.

NASA's Ames Research Center at Moffett Field, Calif., is responsible for the Kepler mission concept, ground system development, mission operations and science data analysis. NASA's Jet Propulsion Laboratory in Pasadena, Calif., managed Kepler mission development. Ball Aerospace & Technologies Corp. in Boulder, Colo., developed the Kepler flight system and supports mission operations with the Laboratory for Atmospheric and Space Physics at the University of Colorado in Boulder. The Space Telescope Science Institute in Baltimore archives, hosts and distributes Kepler science data. Kepler is NASA's 10th Discovery mission and was funded by the agency's Science Mission Directorate.

[OK, not a chance in hell of life here but….. WEIRD! What a strange Galaxy it is out there. No matter what SF writers come up with I bet that Nature can come up with stranger yet!]

NASA's Cassini Spacecraft Reveals Clues About Saturn Moon 

From NASA

December 12, 2013

NASA's Cassini spacecraft is providing scientists with key clues about Saturn's moon Titan, and in particular, its hydrocarbon lakes and seas. Titan is one of the most Earth-like places in the solar system, and the only place other than our planet that has stable liquid on its surface.

Cassini's recent close flybys are bringing into sharper focus a region in Titan's northern hemisphere that sparkles with almost all of the moon's seas and lakes. Scientists working with the spacecraft's radar instrument have put together the most detailed multi-image mosaic of that region to date. The image includes all the seas and most of the major lakes. Some of the flybys tracked over areas that previously were seen at a different angle, so researchers have been able to create a flyover of the area around Titan's largest and second largest seas, known as Kraken Mare and Ligeia Mare, and some of the nearby lakes.

"Learning about surface features like lakes and seas helps us to understand how Titan's liquids, solids and gases interact to make it so Earth-like," said Steve Wall, acting radar team lead at NASA's Jet Propulsion Laboratory (JPL) in Pasadena, Calif. "While these two worlds aren't exactly the same, it shows us more and more Earth-like processes as we get new views."

These new images show Kraken Mare is more extensive and complex than previously thought. They also show nearly all of the lakes on Titan fall into an area covering about 600 miles by 1,100 miles (900 kilometers by 1,800 kilometers). Only 3 percent of the liquid at Titan falls outside of this area.

"Scientists have been wondering why Titan's lakes are where they are. These images show us that the bedrock and geology must be creating a particularly inviting environment for lakes in this box," said Randolph Kirk, a Cassini radar team member at the U.S. Geological Survey in Flagstaff, Ariz. "We think it may be something like the formation of the prehistoric lake called Lake Lahontan near Lake Tahoe in Nevada and California, where deformation of the crust created fissures that could be filled up with liquid."

A creative application of a method previously used to analyze data at Mars also revealed that Ligeia Mare is about 560 feet (170 meters) deep. This is the first time scientists have been able to plumb the bottom of a lake or sea on Titan. This was possible partly because the liquid turned out to be very pure, allowing the radar signal to pass through it easily. The liquid surface may be as smooth as the paint on our cars, and is very clear to radar eyes. The new results indicate the liquid is mostly methane, somewhat similar to a liquid form of natural gas on Earth.

"Ligeia Mare turned out to be just the right depth for radar to detect a signal back from the sea floor, which is a signal we didn't think we'd be able to get," said Marco Mastrogiuseppe, a Cassini radar team associate at Sapienza University of Rome. "The measurement we made shows Ligeia to be deeper in at least one place than the average depth of Lake Michigan."

One implication is that Cassini scientists now can estimate the total volume of the liquids on Titan. Based on Mastrogiuseppe’s work, calculations made by Alexander Hayes, of Cornell University in Ithaca, N.Y., show there are about 2,000 cubic miles (9,000 cubic kilometers) of liquid hydrocarbon, about 40 times more than in all the proven oil reservoirs on Earth. As Cassini gets closer to northern summer in the Saturn system, mission scientists look forward to potentially the most exciting time for weather at Titan's northern hemisphere.

The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency, and the Italian Space Agency. JPL, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate in Washington. JPL designed, developed and assembled the Cassini orbiter. JPL and the Italian Space Agency, working with team members from the US and several European countries, built the radar instrument.

[I wonder if anything can live in that? I mean, that’s a LOT of liquid and its rich in all kinds of interesting chemicals. I wonder….?]