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Mars Rock Supports Cross-Seeding Theory
914 writes "Mars rover Opportunity has found a rock (nicknamed 'Bounce') that "provides conclusive evidence not only of Martian meteorites on Earth, but also of the possibility of cross-seeding." Not only that, but according to the UPI article: 'The discovery of Bounce raises the distinct possibility that life arising from a common source could have existed for a time on both worlds.'"
Analysis: 'Bounce' rock's cosmic portent
By Phil Berardelli
United Press International
Published 4/16/2004 6:07 PM
WASHINGTON, April 16 (UPI) -- Opportunity's phenomenal luck continues.
Not only did NASA's rover land smack-dab in the middle of a neatly excavated and navigable crater on Mars, where it promptly uncovered persuasive evidence that water once flowed across the red planet, and not only has it been performing nearly flawlessly since it touched down on Jan. 24. Now, it also, essentially, has stubbed its toe on a rock whose discovery portends cosmic implications.
A few days ago, on its slow roll across the Martian terrain at its landing site at Meridiani Planum, an iron-oxide-rich area near the planet's equator, Opportunity's controllers noticed an odd-looking, football-shaped rock lying in the red dust. They named the rock "Bounce," because the lander most likely hit it as it bounced along the surface, cushioned by its airbags, before coming to rest inside the little crater called Eagle.
Controllers considered Bounce an odd find because it did not resemble any of the other rocks in the crater's vicinity -- nor did it resemble anything seen before on Mars, they said.
So they ordered Opportunity to train its formidable instruments on the rock, including the tool NASA engineers affectionately called the "RAT," for rock abrasion tool, which grinds away surface impurities to expose the undisturbed, primordial composition below.
The results stunned the NASA team.
The main ingredient in Bounce is a volcanic mineral called pyroxene, said rover science team member Deanne Rogers, of Arizona State University in Tempe. The high proportion of pyroxene means Bounce not only is unlike any other rock studied by Opportunity or Spirit, but also is unlike the volcanic deposits mapped extensively around Mars by NASA's Mars Global Surveyor orbiter, Rogers said.
Bounce is a unique rock, and it has been sitting at Opportunity's feet.
"We think we have a rock similar to something found on Earth," said Benton Clark of Lockheed Martin Space Systems in Denver, a science-team member for the missions of both Opportunity and its twin, Spirit.
Rather more than that. Bounce's chemical composition exactly matches that of a meteorite that hit the ground in Shergotty, India, on Aug. 25, 1865.
Called the Shergotty meteorite -- and the source name for a class of meteorites called shergottites -- its chemical composition is a "matching fingerprint" to Bounce, said David Grinspoon, professor of planetary science at the University of Colorado in Boulder.
The resemblance helps confirm something meteorite specialists and planetary scientists have suspected for more than two decades but until now have been unable to prove: Micro-bubbles of gas trapped in dozens of meteorites found on Earth -- including Shergotty -- match the recipe of Martian atmosphere so closely that they must have originated on Mars.
"There is a striking similarity in spectra," said Christian Schroeder, a rover science-team collaborator from the University of Mainz in Germany, which supplied both Mars rovers with Moessbauer spectrometers -- exceedingly sensitive instruments for identifying chemical compositions.
A less-distinctively named shergottite, EETA79001, found in Antarctica in 1979, has a composition even closer to Bounce's.
As a result, NASA scientists are convinced Shergotty, EETA79001 and Bounce -- and maybe a couple dozen other Martian rocks that found their way to Earth -- were ejected from Mars by the impact of a large asteroid or comet.
The instruments aboard another orbiter, Mars Odyssey, suggest Bounce may have originated at an impact crater about 16 miles wide that lies about 31 miles southwest of Opportunity. The orbiter's images show some of the rocks thrown outward by the impact that formed the crater flew as far as the distance to the rover.
"Some of us think (Bounce) could have been ejected from this crater," Roge
RTFA. Bubbles in the meteorites of this type found on Earth contain gas that matches the martian atmosphere, which strongly suggests they orginated on Mars. Then you have this rock already on Mars that matches them in composition suggesting that certain rocks found on both Earth and Mars have a common source.
Maybe look at two papers - he claims he found a meteorite carrying some weird liveforms in India during some 'Red rain'.
There isn't any kind of evidence there ever was life on Mars, yet this article raises the speculation that life from Mars survived a high temp impact, ejection through the harsh radiation and temperatures of space and "cross-polinated" earth?
This is not supported by any facts and is pure speculation. It doesn't even qualify as junk science.
The authors should wait until we get some data back from Mars confirming that life was even present there before publishing these kind of claims.
I heard physicist and astrobiologist Paul Davies give a talk on this subject just yesterday ;)
Davies proposes that the lower gravity of Mars makes it more likely for Martian rocks to reach earth, than vice versa, though transit both ways is statistically viable.
He also suggests that the faster cooling rate of the Mars crust, the lack of a global ocean, and some of the largest volcanoes in the solar system made Mars a more favorable place for microbial life to form.
http://aca.mq.edu.au/Research/research2003.html
As far as I can recall, we only have meteorites from the Moon and Mars. Worse, a Venus sample return mission seems unlikely for the near future...
Shocked rock: A rock in which its particles have been accelerated to higher than the speed of sound (in the rock). This causes an irreversible (high entropy) change in the rock, and possibly causes melting.
Yes, it's much more likely for meteroites to make it from Mars to Earth than the other way round. Several orders of magnitude more likely. They need much more delta V, although that said a considerable amount is needed just to escape from Mars' gravity well. In other words it is possible but considerably less probable. Whether any microbes would survive an impact of sufficient energy, as well as the long ride through cold vacuum is a different story...
"Studies have shown that people who eat peanuts live longer than those who do not eat."
Meanwhile, back here on earth, fundamentalists still insist that everythying was created in seven days. :-|
Thank you! This is a very important point.
Having searched for shergottite meteorite signatures using orbital data from Mars (no luck yet), and being a close colleague of many of the MER science team members, I can confirm that NO ONE on the MER team is suggesting anything about life on Mars or cross-contamination based on this week's (or any other week's) results.
Although one of the instrument teams (Alpha Particle X-ray Spectrometer - APXS) is suggesting that Meridiani could be the source region of one class of Martian meteorites, their data (bulk chemistry) cannot actually tell us that. (It's also worth noting that the Meridiani plain is believed to be billions of years older than the rocks in this class of meteorites.) Those who were watching the press conference (the press release ignores this) heard that another instrument, the Mini-TES (Thermal Emission Spectrometer), determined that the mineralogy of Bounce is similar in some ways, but NOT identical, to the shergottite meteorite that the APXS team favors, although it IS different than the majority of the rock types observed from orbit.
Mars is smaller than Earth and would have cooled first, allowing lakes and seas for form first.
CDE open sourced! https://sourceforge.net/projects/cdesktopenv/
(b) The Bounce discoveries do not necessarily support the conclusion that life orginated on Mars and came to Earth. All they do is further support the notion that some of the meterorites striking Earth have a Martian origin. Whether or not those meteorites carried biological payloads is a whole different question.
The "recipe" for meteorite identification usually includes the ratio of oxygen isotopes. This ratio varies as you head away from the Sun. So, if you can identify the ratio, you can match pebble A to pebble B (or planet B) fairly well.
Yes, it certainly is possible. However it is unlikely. The sort of analysis that goes into determining the source of origin of a rock is fairly accurate. There are a number of factors which are taken into account which, when combined, form a fairly unique "fingerprint" as to the origin of a piece of rock.
First of all, there is the relative amounts of elements. Mars has a different elemental mix than the Earth due to its distance from the Sun, its mass, the loss of atmosphere and water, among many other factors. Then there is the different proportions of isotopes of each element. Earth, partially due to the shielding afforded by its atmosphere and its magnetic field, has a different mix of isotopes of each element. Remember that each element often has 2 or 3 common isotopes, this significantly contributes to the complexity of the fingerprint.
Then there are differences in rock formation between Mars and the Earth. Rocks formed on Mars have gone through a different history of sedimentation, melting, crystallization, weathering, etc. than those formed on Earth. This results in not only different minerals being formed but also the patterns of how these minerals mix and the relative proportions that one mineral may be found in a mixture with others.
I'm probably missing a few other factors but you get the idea. Remember that the process of identifying rocks is not only used to tell if a rock is from Mars or the Earth but it is also accurate enough to possibly be used to tell if a rock is from near Moscow or from near Los Angeles. Scientists can get a fairly good idea of where on the Earth a diamond or a piece of uranium originated simply by using some of these techniques. Analysis of the isotope ratios alone is a strong indicator.
Sapere aude!
However, the one import thing that can mess with relative isotope concentrations is life itself.
Since I'm a plant biologist i give to examples:
Rubisco, an important enzyme for fotosynthesis, has a preference for lighter isotopes, thus it will carboxylate C-12 in preference to C-13 (and 14).
Heavy Oxygen (what we were discussing) isotopes transpire more slowly from a plant leaf than light oxygen isotopes. Changing the ratio of oxygen isotopes in organic tissues.
Now, I'm not saying you cannot use the gas in air bubbles to see where the rocks come from, I have no idea how much effect these processes have on the isotope ratios in the atmosphere. But you have to keep in might that if they came from a planet infested with life, it may have a slightly different isotope concentration that expected.
The Viking Landers carried, during their descent, mass spectrometers which sampled the Martian atmosphere on the way down. These provided our only measurements of Martian atmosphere isotope ratios to date.
It turns out that isotope ratios tell you a lot about the history of an atmosphere, as different isotopes get lost at different rates by different mechanisms.
The gas isotope ratios in these meteorites are unique to Mars, as measured by Viking. There are many other indications (most meteorites can be traced back to specific asteroid "families", these cannot, etc.), but it was the gas isotope ratios that were convincing.
I saw a debate about this in Paris back in 1985. The "non-Martian" advocate finally had to concede that these meteorites had to come from a planet very much like Mars in its size and history, and distance from the Sun, and were too new to come from any disrupted planet, so basically the only possible source was Mars.
Well the fossil record preserves much of earth history pre-humans, but the fact remains that humans, in our present iteration, haven't been around very long relative to the age of the planet. The human race surely hasn't been around "millions of years". At best we've been here as Homo Sapiens Sapiens for around 130,000 years. Anything that predates what we've found to be historical evidence of past civilizations is usually fiction.
Why are you citing sources such as UPI when posting in Slashdot? I find it hard to believe that sources other than UPI didn't cover the topics covered in UPI's article.
UPI's integrity as a news covering agency has disintegrated years ago and noone buys news from them any more. Just because robots like Google go fetch their articles doesn't mean they are any good.
UPI's integrity and news covering reliability has diminished to zero when a cult bought it, which dates back as long as 2000 which was followed by Helen Thomas leavingleaving in protest (UPI's leading reporter for over 20 years).