We’ve known for some time that water exists in some forms on Mars. The Viking program, which consisted of both orbiter and lander craft, showed that Mars’ surface had many characteristics that must have been shaped by water. Further probes such as Mars Odyssey and the Phoenix Lander showed that much of the present day water that Mars holds is present at the poles, trapped in the vast frozen tundra. There’s been a lot of speculation about how liquid water could exist on Mars today however no conclusive proof had been found. That was until today when NASA announced it had proof that liquid water flows on Mars, albeit in a very salty form.
The report comes out of the Georgia Institute of Technology with collaborators from NASA’s Ames Research Center, Johns Hopkins University, University of Arizona and the Laboratoire de Planétologie et Géodynamique. Using data gathered from the Mars Reconnaissance Orbiter the researchers had identified that there were seasonal geologic features on Mars’ surface. These dark lines (pictured above) were dubbed recurring slope lineae would change over time, darkening and appearing to flow during the warmer months and then fading during the colder months. It has been thought for some time that these slopes were indicative of liquid water flows however there wasn’t any evidence to support that theory.
This is where the MRO’s Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) comes into play. This instrument was specifically designed to detect water on Mars by looking at varying wavelengths of light emitted from the planet’s surface. Once the target sites were identified CRISM was then pointed at them and their surface composition analysed. What was found at the RSL sites were minerals called hydrated salts which, when mixed with water, would lower the freezing point of the water significantly. Interestingly these hydrated salts were only detected in places were the RSL features were particularly wide as other places, where the RSLs were slimmer, did not show any signs of hydrated salts.
These salts, called perchlorates, have been seen before by several other Mars missions although they’ve never been witnessed in hydrated form before. These perchlorates can potentially keep water from freezing at temperatures down to -70°C. Additionally some of these perchlorates can be used in the manufacturing of rocket fuel, something which could prove to be quite valuable for future missions to Mars. Of course they’re likely not in their readily usable form, requiring some processing on site before they can be utilized.
Data like this presents many new opportunities for further research on Mars. It’s currently postulated that these RSLs are likely the result of a shallow subsurface flow which is wicking up to the surface when the conditions are warmer. If this is the case then these sites would be the perfect place for a rover to investigate as there’s every chance it could directly sample martian water at these sites. Considering that wherever we find liquid water on Earth we find life then there’s great potential for the same thing to happen on Mars. If there isn’t then that will also tell us a lot which means its very much worth investigating.
There are some things that, at first glance, seem so absurd that you have to wonder why it was being done. Many are quick to point out even if something looks stupid, but it works, then it isn’t stupid. Indeed that’s what I first thought when I heard that Los Angeles Department of Water and Power was filling up their water reservoirs with millions upon millions of plastic balls as it sounded like some form of a joke. As it turns out it’s anything but and compared to other solutions to the problem it’s actually quite an ingenious project (not to mention how soothing dumping that many balls out of a truck sounds):
The first thing that comes to mind is why use millions of plastic balls instead of say, a giant shade structure to cover the resevoir? As it turns out constructing something like that would be an order of magnitude more expensive, on the order of $300 million compared to the total project cost of the shade balls of approximately $34 million. The balls themselves will last approximately 10 years before they start degrading at which point they’ll likely start splitting in half. Putting that in perspective you’d need the shade structure to last almost 100 years before it would be a better option than the balls, a pretty staggering statistic.
The balls provide numerous benefits, the largest of which is the reduction of water lost to evaporation in the reservoirs. The current reservoirs, which stretch over some 175 acres, hold about 3.3 billion gallons of water and about 10% of that is lost every year to evaporation. These little balls will then save some 300 million gallons of water a year from being lost. Additionally chemicals such as chlorine and bromide can combine into bromate (a potential carcinogen) under sunlight, something which these little plastic balls will help prevent.
In all honesty when I first saw this I thought it was a joke, a viral video that was advertising a plastic company or something equally as banal. However digging further into it the science of it is sound, the cost is far cheaper than the alternatives and the benefits of doing it outweigh the costs.
Colour me impressed.
Whilst the mainstream media would have you believe that the bright spots on Ceres were a surprise to everyone they’ve actually been something we’ve known about for quite some time. However in the past they seemed to come and go making consistent observations of them rather difficult. With the Dawn craft now in a stable orbit around Ceres we are now in the position to observe them much more closely, bringing us ever closer to understanding what the heck it is. There’s still a lot more for us to understand but the first round of preliminary observations have provided some very good insight into the bright spot’s composition and its likely origin.
The first revelation to come out of Dawn’s observations was that the bright spot was in fact not a singular entity and is made up of several spots. There’s 2 large primary bright spots that are accompanied by a bunch of smaller ones which indicates that, as we make better observations, that those larger spots are most likely made up of multiple smaller spots as well. As the above ground map indicates there are actually a bunch of other bright spots dotted over Ceres’ landscape however none of them were close enough together to be observable before Dawn began making closer approaches. The origins of these spots remain something of a mystery however there are several prevailing theories about how they could have been created.
Ceres has been observed as having a very tenuous atmosphere which could only have arisen from outgassing or sublimation from its core. In early 2014 observations of Ceres detected some localized cryovolcanoes which are dumping some 3KG of water out into space every second supporting the theory that there’s some form of water hidden within Ceres. This supports the theory that these bright spots are most likely water ice (which would have the required reflectivity) but at the same time water in a vacuum tends to sublimate very quickly which begs the question of how long these bright spots have been around and how long they’ll last.
It’s quite possible that the ice in the crater was revealed by a recent impact and thus we’re just lucky that the bright spot is there for us to observe it. Considering that Ceres sits within the asteroid belt between Mars and Jupiter this is a very real possibility although that does then raise the question of why we’re not seeing more bright spots than we currently are. This is what then fuels other, more exotic, theories about what’s at the base of that crater such as a large metallic deposit. However evidence to support those theories isn’t yet forthcoming however once Dawn starts making closer approaches there is potential for some to come to light.
Needless to say the next few months of observations will prove extremely valuable in determining the bright spots’ elusive nature. Whilst the reality is likely to be far more dull and boring than any of the exotic theories make it out to be it’s still an exciting prospect, one that will give us insight into how solar systems like ours form.
We’ve known for a long time now that Mars once contained vast reservoirs of water and that even in its apparently dry state there was indications of water still hiding in various places. The search for water on Mars is a twofold with the two main objectives being finding environments suitable to life and secondly for potential use by future manned missions. Whilst we’ve succeed in confirming that yes, water once covered Mars and it still exists there today, we’re still finding out just how extensive the reservoirs are. As it turns out Mars may be flush with more water than we first expected and it’s been right under our noses this entire time.
The surface of Mars is a barren wasteland, covered in the same monotonous coloring that gives it that signature red tinge. The poles are the exception to this, harboring large water ice caps that get blanketed with a layer of dry ice (frozen carbon dioxide) in the winter. The reason for this is that due to the low pressure of Mars’ atmosphere exposed water anywhere else on the planet simply subliminates, turning straight from ice to water vapor before being swept away by Mars’ turbulent winds. However new research from the University of Copenhagen has revealed that water ice has managed to survive in other places around Mars and has done so in great quantities.
As it turns out many of the geological features we’ve observed on Mars that we’ve assumed to simply be mountains or hills are in fact dust covered glaciers which pepper the martian surface near the poles. This thick layer of dust has protected them from Mars’ atmosphere, preventing the ice from sublimation away. This dust also makes them appear like any other geological feature that you’d find on Mars’ surface instead of the towering walls of ice that we’re used to seeing here on Earth. The researchers were able to determine that these were water ice glaciers by using radar measurements from the numerous spacecraft we have orbiting the red planet and how they’re flowing under their protective dust blankets.
The amount of ice that these glaciers contain is quite staggering, enough that if it was spread out over the surface of Mars it would blanket it in a layer 1.1m thick. Such giant reservoirs provide huge opportunities for both exploration and scientific purposes and potentially paves a way for a sustainable human settlement. Whilst liquid water is always the most viable place to look for life we’ve found dozens of examples of microbial life living in some pretty harsh conditions and these glaciers might be a great place to start looking. That and water is one of the main components in several types of rocket fuel, something we’ll need if we want to do multiple return missions to Mars.
It’s incredible to note that our view of Mars has changed so drastically over the past couple decades, going from a barren wasteland that could never have housed life to a viable candidate, flush with water reserves everywhere. This latest discovery just goes to show that we can’t simply rely on visual data alone as even a well studied planet like Mars can still hide things from us and can do it in plain sight. The next step is to dig beneath Mars’ thick dust blanket to peer into these glaciers and, potentially, find something wriggling down there.
There’s many ways to look for life on other planets. Most of our efforts currently focus on first finding environments that could sustain life as we know it which is why the search (and subsequent discovery) of water on other celestial bodies is always a cause for celebration. Once we’ve got a target though the search needs to become more nuanced as we have to seek out the clues that life leaves behind or the blocks that build it. For life as we know it one of the first things we can look for is the presence of organic molecules, the essential parts that make up all of life as we know it. One of these such molecules is methane, reknown for being a component in flatulence, something which Curiosity recently detected on Mars.
Methane, and other organic compounds, don’t necessarily require life in order to form however their presence does indicate that there was an environment favourable to life at one point in time. For Mars this was some time ago, on the order of billions of years, and so it’s highly unlikely that any remaining methane is due to microbial activity. However there has to be some local source of methane near Curiosity as it detected a ten fold spike in the amount of methane in Mars’ atmosphere, something which it has never seen before. Additionally Curiosity detected other organic molecules in a rock it drilled into recently, indicating that there was a time when organics must have been prevalent across the entire surface of Mars.
The discovery was made sometime ago however the researchers needed to rule out the possibility that the reading was caused by organics that were trapped in Curiosity’s sensors from Earth. Things like this happen more often than you think as whilst we take every precaution to ensure that there isn’t any contaminations on craft like this it’s inevitable that the sensors, all of which are highly complex machines, end up having stray molecules trapped within them. Because of that however we’ve gotten pretty good at identifying when things came along for the ride and this particular methane spike didn’t originate from Earth.
The organics in the rock are most intriguing however as they tell a story of Mars’ atmosphere that stretches back to the point where it still held liquid water on its surface. The ratio of isotopes in the water (which I talked about yesterday in regards to the discoveries Rosetta has made) indicates that the mineral formed some time after Mars lost much of its water, if we assume that the water on Mars and Earth came from the same place. However the ratio is also radically different to the water in Mars’ atmosphere today indicating that it formed before Mars lost the rest of its surface water. It will be interesting to see how this sample compares to other places around Mars as it will paint a detailed picture of the planet’s surface over time.
It seems like it will be only a matter of time before we find a large source of water on Mars, buried deep beneath the surface somewhere. From there we’ll have an exciting period of analysis to determine if microbial life still thrives on what appears to be a dead planet. Unfortunately that’s not likely to happen any time soon, at least not until we get people there anyway, but with NASA recommitting themselves to such an endeavour it might come sooner than many first thought. Honestly I can’t wait for that to occur as it will shed so much light on how life evolves and, possibly, what it can become.
The origin of Earth’s water is still something of an open debate. The popular theory at the moment is that the primordial Earth was far too hot to contain any form of liquid water, its molten surface still reeling from the cataclysmic events that led to its creation. However others postulate that the water was trapped deep below the surface, only to arise later on as the Earth cooled and an atmosphere developed. It’s an interesting question not only because of how fundamental water is to life but also because we seem to have a lot more of it than any other planet in the solar system. Thus the question of where it came from, and why it’s managed to stick around for so long, is one of continuous scientific enquiry, including such missions as the recently celebrated Rosetta probe.
If we run with the theory that Earth’s water came from some extraplanetary source then the question turns to what the original source might be. Comets seem like a good candidate as they’re primarily water ice by composition and were far more common during the early stages of Earth’s life than they are now. However measurements of isotopes within water of several comets, including Halley, Hyakutake and Hale-Bopp has shown that they are not likely the primary source of water that’s currently on Earth’s surface. The composition of water found on asteroids and other water formed minerals on the Moon seem to indicate that a source closer to home is far more likely which Rosetta’s latest data appears to confirm.
The comet that Rosetta was investigating, the romantically named 67P/Churyumov–Gerasimenko, has a ratio of isotopes that is completely different to anything that’s seen on Earth. The reason that this is important is due to it’s orbit as 67P is what we call a Jupiter class comet, a collection of various comets that have orbits that don’t extend far past Jupiter. It was thought that these kinds of comets would have been more likely to have been involved in the creation of Earth’s oceans than comets from further out, due to their proximity. However 67P, with its wildly different composition to Earth (and even other bodies in the same vicinity), lends credence to the idea that comets aren’t the likely source of Earth’s oceans. Indeed it’s far more likely that water and minerals trapped in asteroids are the likely source, based on how similar their composition is.
Now this doesn’t rule out comets completely as there’s potential for further out Kuiper belt class comets to have the composition we’re looking for but it’s looking far more likely that objects from within the asteroid belt are responsible for the oceans we have today. What the mechanism was for them making their way to Earth, whether it was early on in the cataclysmic forming of our solar system or later on when things calmed down, is something that’s still an open question. It’s one we might also have answers to very soon as Dawn is scheduled to arrive at Ceres early next year, the biggest object in the asteroid belt. What Dawn finds there might be the key to unlocking the secrets of our Earth’s oceans and, potentially, the asteroid belt itself.
All life as we know it has one basic need: water. The amount of water required to sustain life is a highly variable thing, from creatures that live out their whole lives in our oceans to others who can survive for months at a time without a single drop of water. However it would be short sighted of us to think that water was the be all and end all of all life in our universe as such broad assumptions have rarely panned out to be true under sustained scrutiny. That does leave us with the rather puzzling question of what environments and factors are required to give rise to life, something we don’t have a good answer to since we haven’t yet created life ourselves. We can study how some of the known biological processes function in other environments and whether that might be a viable place for life to arise.
Researchers at the Washington State University have been investigating the possibility of fluids that could potentially take the place of water in life on other planets. Water has a lot of properties that make it conducive to producing life (as we know it) like dissolving minerals, forming bonds and so on. The theory goes that should a liquid have similar properties to that of water then, potentially, an environment rich in said substance could give rise to life that uses that liquid as its base rather than water. Of course finding something with those exact properties is a tricky endeavour but these researchers may have stumbled onto an unlikely candidate.
Most people are familiar with the triple point of substances, the point where a slight change in pressure or temperature can change it from any of its one three states (solid, liquid, gas) instantly. Above there however there’s another transition called the supercritical point where the properties of the gaseous and liquid phases of the substance converge producing a supercritical fluid. For carbon dioxide this results in a substance that behaves like a gas with the density of its liquid form, a rather peculiar state of matter. It’s this form of carbon dioxide that the researchers believe could replace water as the fluid of life elsewhere, potentially life that’s even more efficient than what we find here.
Specifically they looked at how enzymes behaved in supercritical CO2 and found that they were far more stable than the same ones that they had residing in water. Additionally the enzymes became far more selective about the molecules that they bound to, making the overall process far more efficient than it otherwise would have been. Perhaps the most interesting thing about this was that they found organisms were highly tolerant of this kind of fluid as several bacteria and their enzymes were found to be present in the fluid. Whilst this isn’t definitive proof for life being able to use supercritical CO2 as a replacement for water it does lend credence to the idea that life could arise in places where water is absent.
Of course whether that life would look like anything we’d recognise is something that we won’t really know for a long time to come. An atmosphere of supercritical C02 would likely be an extremely hostile place to our kind of life, more akin to Venus than our comfortable Earth, making exploration quite difficult. Still this idea greatly expands our concept of what life might be and what might give rise to it, something which has had an incredibly inward view for far too long. I have little doubt that one day we’ll find life not as we know it, I’m just not sure if we’ll know it when we see it.
It may seem like scientists spend an inordinate time studying water but there’s a pretty good reason for that. Water is fundamental to all forms of life on Earth so understanding its origins and what roles it plays is crucial to understanding how life came to be and where we might find it. The vast majority of Earth’s water is contained in its oceans which were thought to have formed when comets bombarded its surface, seeding them across the world. However recent research has shown that the oceans may have formed in a different way and that Earth may have much more water contained in it than previously thought.
A recent study done by Steven Jacobsen and his team at Northwestern University has revealed that Earth has a subsurface reservoir that may contain 3 times the volume of the Earth’s surface oceans. They discovered this information by using data from a wide variety of seismometers, those instruments that measure the intensity of the pressure waves of earthquakes, and figuring out how the waves travelled through the Earth’s interior. This is nothing new, it’s how we’ve figured out the rough compositions of the different layers of the Earth’s inner layers previously, however Jacobsen postulated that water in ringwoodite would slow the waves. After testing a sample of ringwoodite to confirm this theory (shown above) his team found data to support the existence of a large layer of ringwoodite in the Earth’s mantle. Whilst this isn’t a subsurface ocean like some heavenly bodies in our solar system have it is a rather interesting discovery, one that supports an entirely different theory of how our surface oceans formed.
The initial hypothesis (at least the one I’m familiar with) is that the Earth bound itself together out of all the varying bits of debris that existed after the sun had formed itself. At this point Earth was a ball of lava, a fiendishly unfriendly environment devoid of any kind of life. Then, as the planet cooled, comets rained down on its surface, supplying the vast amounts of water we now see today. The discovery of this layer of ringwoodite on the other hand suggests that the water may have been present during the initial formation and that instead of other comets providing all the water it instead seeped up, filling all the crevices and crags of the Earth’s surface. It’s interesting because it now links Earth more directly to our other celestial neighbours, those which you’d never consider Earth-like at all.
Saturn’s Europa and Jupiter’s Ganymede for instance are both hypothesized to have vast bodies of water under their surfaces. Up until this discovery you would be forgiven for thinking that their initial formation was likely due to their immediate environment (I.E. those massive gas giants right next to them) however it’s more likely that all heavenly bodies form along a similar path. Thus oceans like ours are probably more likely than not for planets of similar size to ours. Of course there are also numerous other factors that can push things in one way or another (see Mars and Venus for examples of Earth like planets are nothing like Earth) but such similarities really can’t be ignored.
In all honesty this discovery surprised me as I had always been a subscriber to the “comet bombardment” theory of Earth’s oceans. This evidence however points towards an origin story where water formed a core part of Earth’s structure, only to worm its way to the surface long after it cooled. Come to think of it this probably also explains (at least partially) how Earth’s atmosphere likely came to existence, the gases slowly seeping out until it was blanketed in carbon dioxide, only to be turned into the atmosphere we know today by plants. I’m keen to see what other insights can be gleaned for this data as I’m sure this isn’t the only thing Jacobsen’s team discovered.
Correction: My good friend Louise correctly pointed out that our atmosphere started off being almost completely carbon dioxide and only had the composition we know today thanks to plans. She also pointed out I used the wrong “it’s” in the title which, if I didn’t know any better, would say to me that she wants to be my copy editor 😉
The search for life beyond that of our planet is a complicated one. As it stands we only know of life arising in a particular way, one we can’t be sure isn’t unique in the universe. Still it’s the best model we have to go by and so when we search for life we look for all the same signs as we do for anywhere here on Earth. The one constant that binds all life on Earth is water and so that is why we search so fervently for it anywhere in the solar system. Surprisingly there are many places to find it but none are more spectacular than Saturn’s moon Enceladus.
Enceladus is a strange world, truly unlike anything else in our solar system. Its surface is incredibly young, mostly devoid of the numerous pockmarks that are common among other atmosphereless celestial bodies. This is because it’s in a constant state of change, it’s icy surface splitting and cracking open to reveal a new unsullied surface. Enceladus is like this because Saturn’s massive girth warps the tiny moon as it makes its orbit, generating incredible amounts of heat in the process. The same process is responsible for the amazing cryovolcanoes that dot its south pole, spewing forth tons of water per day into the depths of space. Whilst it’s easy to confirm that there’s liquid water somewhere on Enceladus (those cryovolcanoes aren’t magical water spouts) the question of where the reservoir is, if there even is one, has been the subject of much scientific study.
It has long been thought that Enceladus was host to a vast underground ocean although its specifics have always been up for debate. Unlike Europa which is thought to have a layer of liquid water underneath the ice (or a layer of “warmer” ice) the nature of Enceladus’ ocean was less clear. However data gathered by the Cassini spacecraft during its flybys of the moon in 2010~2012 show that it’s very likely that there’s a subsurface ocean below the area where the plumes originate. How they did this is quite incredible and showcases the amazing precision of the instruments we have up in space.
The measurements were made by using the radio communications between Cassini and Earth. These stay at a relatively fixed frequency and thus any changes in the craft’s speed will manifest themselves as slight Doppler Shifts in the frequency. This is the same principle behind how the sound of an approaching ambulance changes as it gets closer and farther away and it allows us to detect even the smallest changes in Cassini’s speed. As it turns out when Cassini flew over Enceladus’ south pole, which has a great big depression in it (meaning there’s less gravity at that point) the change in speed was far less than what we expected. What that means is there’s something more dense below the depression that’s making up for the lack of matter in the depression and, since water is more dense than ice, a giant hidden sea is a very plausible explanation.
There may be other explanations of course, like a giant deposit of heavy elements or just plain rock, however the fact that there’s water gushing up from that location gives more credence to the theory that it’s an ocean. The question now turns to nailing down some of the other variables, like how big it actually is and how the water gets to the surface, which I’m not entirely sure the Cassini craft is capable of determining. Still I wasn’t completely sure it was capable of doing this before today so I’m sure the scientists at NASA have some very interesting ideas about what comes next for Enceladus.
There’s an argument to be made that we should be in total control of everything that goes into our bodies and I support that idea to an extent. However when your decision can adversely impact the lives of others that’s when I support intervention which is why I wholly support compulsory vaccination. This also extends to my support of water fluoridation as, again, whilst there’s numerous arguments that can be made against it the fact that it will benefit so many at almost no risk to others means it’s a net positive for us as a whole. Of course this hasn’t stopped a vocal minority from claiming all sorts of horrific things happening due to water fluoridation the worst of which being that it’ll make you stupid.
A single article on Huffington Post usually wouldn’t warrant my attention, it’s not exactly known as the bastion of sound scientific reporting, but it came across my path not long after a similar post from a Facebook page called The Mind Unleashed claiming that fluoride in water lowered IQ significantly. Because I couldn’t help myself I spent a good couple hours tracking down the research and other articles relating to it. Just like most reporting on scientific discoveries this one is completely overblown and, when you dig into the details, doesn’t support the conclusions that many would draw from it.
I’d love to say that I was surprised by this but this isn’t my first rodeo with bullshit.
A review of water fluoridation studies done researchers at Harvard University concluded that whilst water fluoridation may affect IQ scores the levels that were detected in the study were at least 10 times higher than what’s found in artificially fluoridated water. Additionally the studies failed to control for other variables which are known to affect brain development and IQ scores like the fact that many of the studies were conducted in highly polluted areas in China. Funnily enough the control group in one of the studies were consuming water with similar levels of fluoridation to that of developed countries which shows pretty clearly that the current dosage levels work without the noted side effects.
On the flip side there’s a lot of research that shows water fluoridation reduces cavities in children and adults by a significant percentage, even in those who already have access to it through other means (like toothpaste or as an additive in other food staples). Indeed if you’ll allow me to get hand wavy for a bit there’s evidence to suggest that the average IQ has been trending upwards for the last hundred years or so called the Flynn effect. If fluoridation had a significant impact on IQ scores then we should’ve seen a harsh dip around 1960 when in fact we see the exact opposite. Now correlation does not equal causation but it’s a pretty good indicator that the negative isn’t true.
I could go on but the fact is that water fluoridation works incredibly well as a public health policy, greatly helping those who are at risk at developing tooth cavities and even those who’d consider themselves not needing it. Therefore removing it would cause harm to those who can least afford it to happen to them and that’s why bad science reporting like this needs to be exposed for what it is. I know I’m probably preaching to the choir here but I know how hard it can be to debate people who spout nonsense as fact and hope that you can use this as a reference rather than having to disappear down the research hole that I did.