Tag: martian atmosphere

News From Space: We Come From Mars!

Mars_Earth_Comparison-580x356Men are from Mars, women are… also from Mars? That is the controversial theory that was proposed yesterday at the annual Goldschmidt Conference of geochemists being held in Florence, Italy. The proposal was made by Professor Steven Benner of the Westheimer Institute of Science and Technology in Florida and is the result of new evidence uncovered by his research team.

The theory that life on Earth originated on Mars has been argued before, but has remained contentious amongst the scientific community. However, Benner claims that new evidence supports the conclusion that the Red Planet really is our ancestral home by demonstrating that the elements for life here could only form on Mars, and came here via a Martian meteorite.

Asteroid-Impacts-MarsAccording to the theory, rocks violently flung up from the Red Planet’s surface during mammoth collisions with asteroids or comets then traveled millions of kilometers across interplanetary space to Earth. Once they reached Earth’s atmosphere. they melted, heated and exploded violently before the remnants crashed into the solid or liquid surface.

All that would be needed is for a few of those space born rocks to contain microbes from Mars surface. These building blocks of life would have to survive the journey through space and the impact on Earth to make this happen. But research into Exogenesis – the possibility that life was transplanted on Earth by meteorites – has already shown that this is possible.

curiosity_sol-177-1What’s more, NASA’s Curiosity Rover was expressly created to search for the the environmental conditions that would support life. Less than half a year into its mission it accomplished just that, locating proof of the existence of water and a habitable zone. Between it and the Opportunity Rover, the search to determine if life still exists – in the form of organic molecules – continues and is expected to yield results very soon.

But of course, Benner was quick to point out that there is a difference between habitability (i.e. where can life live) and origins (where might life have originated). The presence organic molecules alone is not enough when it comes to the mystery of life’s creation, and when it comes to making the great leap between having the necessarily elements and the existence of living organisms, scientists remain hung up on two paradoxes.

These are known as the tar paradox and the water paradox, respectively. The former paradox addresses how life as we know it comes down to the presence of organic molecules, which are produced by the chemistry of carbon and its compounds. However, the presence of these compounds does not ensure the creation of life, and laboratory experiments to combine and heat them has only ever produced tar.

mars_lifeAs he puts it, the origin of life involves “deserts” and oxidized forms of the elements Boron (B) and Molybdenum (Mo) – namely borate and molybdate. Essentially, these elements are the difference between the formation of tar and RNA, the very building block of life:

Certain elements seem able to control the propensity of organic materials to turn into tar, particularly boron and molybdenum, so we believe that minerals containing both were fundamental to life first starting. Analysis of a Martian meteorite recently showed that there was boron on Mars; we now believe that the oxidized form of molybdenum was there too.

The second paradox relates to water, which is believed to be intrinsic for life to flourish, but can be also hazardous to its formation. According to modern research, RNA forms prebiotically, requiring mineral species like borate to capture organic elements before they devolve into tar and molybdate to arrange the material to give it ribose – organic sugars, also intrinsic to life.

Mars-snow-header-640x353This can only occur in deserts, he claims, because water is detrimental to RNA and inhibits the formation of borates and molybdates. And from a geological standpoint, there was simply too much water covering the early Earth’s surface to allow for this creation process to take place:

[W]ater is corrosive to RNA, which scientists believe was the first genetic molecule to appear. Although there was water on Mars, it covered much smaller areas than on early Earth. Various geologists will not let us have these [borates and molybdates] on early Earth, but they will let us have them on Mars. So IF you believe what the geologists are telling you about the structure of early Earth, AND you think that you need our chemistry to get RNA, AND IF you think that life began with RNA, THEN you place life’s origins on Mars,

All of this has served to throw the previously-held theory – that life came to Earth through water, minerals and organics being transported by comets – into disarray. Based on this new theory, comets are a bad candidate for organic life since they lack the hot, dry conditions for borate and molybdate formation.

Living-Mars.2If the new theory is to be believed, Mars boasted the proper conditions to create the elements for life, while Earth possessed the water to help it flourish. If such a partnership is needed for the creation of organic life, then scientists will need to reevaluate the likelihood of finding it elsewhere in the universe. Between the existence of water and hot dry environments, life would seem to require more specialized conditions than previously though.

But of course, the debate on whether Earthlings are really Martians will continue as scientific research progresses and definitive proof is discovered and accepted by the majority of the scientific community. In the meantime, Curiosity is expected to rendezvous with Mount Sharp sometime next spring or summer, where it will determine if organic molecules and elements like Boron and Molybdenum exist there.

And on Nov. 18th, NASA will launch its next mission to Mars – the MAVEN orbiter – which will begin studying the upper Martian atmosphere for the first time, determining its previous composition, and where all the water went and when was it lost. So we can expect plenty more news to come to us from our neighboring Red Planet. Wait and see!

Source: universetoday.com

News From Space: MAVEN’s “Time-Machine” for Mars

marsYes, the name is a bit of a attention-getter, but when you come to understand the purpose behind Lockheed Martin’s new spacecraft, the description does appear to be quite apt. It’s known as MAVEN, which stands for Mars Atmosphere and Volatile EvolutioN, and it is currently being produced in Lockheed Martin’s Martin Space Systems facility in Denver, Colorado.

People may recall how earlier this year, MAVEN was mentioned as part of the “Going to Mars” campaign. A project that is being organized by the University of Colorado at Boulder’s Laboratory for Atmospheric and Space Physics (CU/LASP), the Martian orbiter will be carrying a DVD featuring the names of everyone who applies, as well as three specially-selected haikus.

However, it is MAVEN’s larger mission which is now the focus of much interest. Later this year, NASA will be launching the orbiter to Mars for the sake of examine the atmosphere and answering some burning questions that remain about the planet. Thanks to evidence provided by Curiosity, Opportunity, and other missions, scientists now know that the Martian surface once boasted conditions suitable for life, including liquid water.

maven_orbitHence, Maven’s ultimate purpose, which will be will to orbit the planet and examine whether the atmosphere could also have provided life support. Scientists working on the Maven mission want to understand what this atmosphere was like, and the processes that led to its destruction. As Guy Beutelschies, Maven Programme Manager at Lockheed Martin, put it:

What we know from our missions looking at the surface of Mars is that there used to be water there. We can see the outlines of ancient rivers, the shorelines of ancient oceans. But water can’t exist there now – the atmosphere is too thin and too dry, any water would just evaporate or freeze. 

So the big question is what happened to Mars’ atmosphere? Short of being able to travel back in time into the Martian past, how would anyone go about tackling these questions with a mission today? Beutelshcies explained it as follows:

[The atmosphere] used to be thicker, warmer, wetter, now it’s thin and dry. How did we get there? In a sense we are building a little bit of a time machine. What we’re doing is understanding the processes.

maven_atmosphereJust last week, evidence provided by the Curiosity rover supports the theory that Mars may have lost most of its atmosphere billions of years ago. Still, scientists remain skeptical that Mars once had an atmosphere comparable to that of Earth. Today, that atmosphere is roughly one-hundredth the thickness of Earth’s, made up mostly of carbon dioxide and a tiny fraction of water vapor. What little remains is being stripped away by the solar wind.

And unlike Earth, Mars does not have a magnetosphere to protect its atmosphere from being blown away – at least not anymore. Such a fragile, thin band around is now unlikely to support any sort of life, as far as we know. But the atmosphere in the past must have been more substantial to allow the formation of rivers, lakes and oceans.

mars_sunsetBruce Jakosky, the Principal Investigator for Maven who is based at the University of Colorado’s CU/LASP lab in Boulder, claims:

We think that Mars used to have a magnetic field. We see places on the surface that retain some remnant magnetism, they were imprinted when they formed with whatever magnetism was there. We think that some four billion years ago, when the magnetic field turned off, that turn-off of the magnetic field allowed [for the] turn-on of the stripping by the solar wind.

To investigate the processes taking place today, Maven will dip into the Martian upper atmosphere with each orbit, measuring the particles, sampling gases, monitoring the magnetic field and solar wind. Whereas the rovers have looked at the atmosphere from the ground up, MAVEN will look at it from the top down. At this point, both are needed to put together a picture of what’s controlling the Mars environment.

maven_atmo1As well as filling in the blanks about Mars’ depleted atmosphere, Maven will also provide clues to the habitability of other planets beyond the solar system. As Jakosky said, the research conducted will have far-reaching implication for our understanding:

In trying to understand the distribution of life throughout the Universe, this is a really important indicator. Understanding the environmental conditions that allow [life] to exist, or don’t allow it to exist, is key to being able to extrapolate elsewhere.

What’s more, understanding what happened to Mars will provide some key insight into the history of our Solar System, and how it went from being a star with two planets that had oceans and atmospheres to just one. Knowing why things continued to operate on Earth, while on Mars they went horribly wrong, is likely to be quite the eye-opener, and make us all thankful we evolved here on Earth.

Source: bbc.com

 

News from Mars: Evidence of Falling Snow

Mars-snow-header-640x353Ever since astronomers first looked up at Mars, they discerned features that few could accurately identify. For many years, speculations about irrigation, canals, and a Martian civilization abounded, firing people’s imaginations and fiction. It was not until more recently, with the deployment of the Viking probe, that Mars’ surface features have come to be seen for what they are.

Thanks several more probes, and the tireless work of rover such as Opptorunity and Curiosity, scientists have been able to amass evidence and get a first hand look at the surface. Nevertheless, they are still hard-pressed to explain everything that they’ve seen. And while much evidence exists that rivers and lakes once dotted the landscape, other geological features exist which don’t fit that model.

curiosity_rocksHowever, a recent report from Brown University has presented evidence that snowfall may be one answer. It has long been known that ice exists at the polar caps, but actual snowfall is a very specific meteorological feature, one that has serious implications for early Martian conditions. This is just another indication that Mars hosted an environment that was very much like Earths.

And this is not the first time that snow on Mars has been suggested. In 2008, NASA announced having detected snow falling from Martian clouds, but it was entirely vaporized before reaching the ground. The Brown researchers claim that snowfall in the past, and buildup on the surface leading to melting and runoff, could have created many of the tributary networks observed near tall mountain-ranges.

mars_atmoTo back this claim up, the team used a computer simulation from the Laboratoire de Météorologie Dynamique called the Mars global circulation model (GCM). This model compiles evidence about the early composition of the red planet’s atmosphere to predict global circulation patterns. And since other models predict that Mars was quite cold, the program indicated the highest probability of snowfall over the densest valley systems.

Lead researcher Kat Scanlon also relied on her background in orographic studies (science for “studying mountains”) in Hawaii to arrive at this hypothesis. This includes how tall mountains lead to divergent weather patterns on either side, with warm, wet conditions one and cold, dry ones on the other. NASA’s Curiosity rover also was intrinsic, thanks to recent information that might explain why Mars no longer displays this kind of behavior.

Curiosity-Laser-BeamIn short, Curiosity determined that the planet is losing its atmosphere. It has taken detailed assays of the current atmosphere, which is almost entirely carbon dioxide and about 0.6% the pressure of Earth’s at sea-level. More notably, it has used its ability to laser-blast solid samples and analyze the resulting vapor to determine that Mars has an unusually high ratio of heavy to light isotopes — most importantly of deuterium to hydrogen.

The main explanation for this is atmospheric loss, since light isotopes will escape slightly more quickly than heavy. Over billions of years, this can lead to non-standard isotope levels the show a loss of atmosphere. One major theory that might explain this loss say that about 4.2 million years ago Mars collided with an object about the size of Pluto. An impact from this body would have caused a huge expulsion of atmosphere, followed by a slow, continued loss from then on.

All of this plays into the larger question of life on Mars. Is there, or was there, ever life? Most likely, there was, as all the elements – water, atmosphere, clay minerals – appear to have been there at one time. And while scientists might still stumble upon a Lake Vostok-like reserve of microbial life under the surface, it seems most likely that Mars most fertile days is behind it.

However, that doesn’t mean that it can’t once again host life-sustaining conditions. And with some tweaking, of the ecological engineering – aka. terraforming – variety, it could once again.

Living-Mars.2Source: extremetech.com