"Biomorphs" found on meteorites traced to Mars have been proposed as evidence that life has existed on the Red Planet
Posted on 05/04/2010 12:55:53 AM PDT by Palter
NASA's Mars Meteorite Research Team reopened a 14-year-old controversy on extraterrestrial life last week, reaffirming and offering support for its widely challenged assertion that a 4-billion-year-old meteorite that landed thousands of years ago on Antarctica shows evidence of microscopic life on Mars.
In addition to presenting research that they said disproved some of their critics, the scientists reported that additional Martian meteorites appear to house distinct and identifiable microbial fossils that point even more strongly to the existence of life.
"We feel more confident than ever that Mars probably once was, and maybe still is, home to life," team leader David McKay said at a NASA-sponsored conference on astrobiology.
The researchers' presentations were not met with any of the excited frenzy that greeted the original 1996 announcement about the meteorite -- which led to a televised statement by President Bill Clinton in which he announced a "space summit," the formation of a commission to examine its implications and the birth of a NASA-funded astrobiology program.
Fourteen years of relentless criticism have turned many scientists against the McKay results, and the Mars meteorite "discovery" has remained an unresolved and somewhat awkward issue. This has continued even though the team's central finding -- that Mars once had living creatures -- has gained broad acceptance among the biologists, chemists, geologists, astronomers and other scientists who make up the astrobiology community.
"Biomorphs" found on meteorites traced to Mars have been proposed as evidence that life has existed on the Red Planet
(Excerpt) Read more at washingtonpost.com ...
NASA PR flacks have already denounced this release. Too many of the geologists and “earth” science types at JPL would be put out of a job if this news got corroborated.
For that matter, could Obama and company withstand the likely public pressure for a manned expedition to investigate life on Mars if it ever appeared that such a thing was likely? Even their Defense Dept. budget eviscerations would have to be put on hold in such an event.
With all the evidence that Mars was once covered with flowing water. Its very ignorant for any scientist to say there is no life on mars, there never was or ever will be.
Just ask Helen. She saw it land.
How many scientists throughout history have proclaimed things to be impossible only to be punked later on? Too many to count.
OK, **IF** it is possible that ejecta from Mars made it to earth (and I see that as REMOTE) HOW can one establish that this particular piece of ejecta/meteorite came from MARS since there is no other sample to confirm/compare/verify? That this meteorite came from MARS is pure speculation, not science.
Doesn’t mean it’s not possible. But come on.
Also if ejecta from MARS could make it to earth, then the reverse is also true. Perhaps early life from earth colonized early MARS via ejecta. A plausible pan-spermism theory if you like those.
Clearly, the science is settled, so why do we continue the discussions?
The Viking Mission to Mars back in the 70s conducted remote tests on rocks there and did an isotope analysis. Some meteorites on Earth match up identically to them chemically. It is like a DNA match.
OK we have a decent correlation. Would not call it proof or even conclusive. IT is fun to speculate though.
I’m not sure if the NASA Viking mission did remote testing of Martian rocks. It may have only analyzed its atmosphere remotely and then matched it chemically to gases trapped within meteorites found on Earth.
“...unheralded measurement by the two NASA Viking spacecraft that landed on Mars in 1976. Although sent to conduct experiments to detect extant life in Martian soil (which they did not), the Viking landers gained redemption of sorts because the instruments measured the amounts of different gases in the thin Martian atmosphere. Those same gases were first found in 1983 by Donald Bogard and Pratt Johnson in very small amounts (but in the exact same proportions) trapped within shock glass veins and pockets in shergottite Elephant Moraine 79001, and now in at least five other Martian meteorites [on Earth].”
http://www.imca.cc/mars/martian-meteorites.htm
_____________________________________________
From NASA:
“Why are they from Mars?
The 31 meteorites are unusual igneous meteorites (SNC achondrites named Shergotty, Nakhla, Chassigny are type examples). Most martian meteorites are 1.3 billion years old or less, much younger than typical igneous meteorites from asteroids which are 4.5 billion years old. They also have higher contents of volatiles than igneous meteorites. The conclusive evidence that the SNC meteorites originated on Mars comes from the measurement of gases trapped in one meteorite’s interior. The trapped gases match those that Viking measured in the martian atmosphere.”
http://curator.jsc.nasa.gov/antmet/marsmets/index.cfm
OK, here’s where they reach a shaky conclusion: “The conclusive evidence that the SNC meteorites originated on Mars comes from the measurement of gases trapped in one meteorite’s interior. The trapped gases match those that Viking measured in the martian atmosphere.”
That only “proves” the gases match. For ONE meteorite. hmmm is THAT good science?
It enables a fun hypothesis, NOT a conclusion.
Still it would be nice to GO to MARS and prove/dis-prove all this.
From my first link:
“and now in at least five other Martian meteorites [on Earth].”
http://www.imca.cc/mars/martian-meteorites.htm
From NASA, Nov 2009:
New Study Adds to Finding of Ancient Life Signs in Mars Meteorite
HOUSTON — Using more advanced analytical instruments now available, a Johnson Space Center research team has reexamined the 1996 finding that a meteorite contains strong evidence that life may have existed on ancient Mars.
The new research focused on investigating alternate proposals for the creation of materials thought to be signs of ancient life found in the meteorite. The new study argues that ancient life remains the most plausible explanation for the materials and structures found in the meteorite. ...”
http://www.nasa.gov/centers/johnson/news/releases/2009/J09-030.html
This proves there has been life on Mars. Afterall someone was throwing those rocks at us.
“In 1983 it was suggested by Smith et al. [3] that meteorites in the so called SNC group (Shergottites, Nakhlites, Chassignites) originated from Mars, from evidence from an instrumental and radiochemical neutron activation analysis of the meteorites. They found that the SNC meteorites possess chemical, isotopic, and petrologic features consistent with data available from Mars at the time, findings further confirmed by Treiman et al. [4] a few years later, by similar methods. Then in late 1983, Bogard et al. [5] showed that the isotopic concentrations of various noble gases of some of the shergottites were consistent with the observations of the atmosphere of Mars made by the Viking spacecraft in the mid-to-late 1970s.
In 2000, an article by Treiman, Gleason and Bogard gave a survey of all the arguments used to conclude the SNC meteorites (of which 14 had been found at the time) were from Mars. They wrote, “There seems little likelihood that the SNCs are not from Mars. If they were from another planetary body, it would have to be substantially identical to Mars as it now is understood.”[6]
Composition
33 of the 34 Mars meteorites are divided into three rare groups of achondritic (stony) meteorites: shergottites (24), nakhlites (7), and chassignites (2), with the oddball meteorite ALH 84001 not usually placed in a group.[1] Consequently, Mars meteorites as a whole are sometimes referred to as the SNC group. They have isotope ratios that are said to be consistent with each other and inconsistent with the Earth. The names derive from the location of where the first meteorite of their type was discovered.”
http://en.wikipedia.org/wiki/Mars_meteorite
Ok I should have caught that. ;-)
But, the ‘scientist’ still concludes/presumes that the meteorites under study are definitively Martian ejecta.
It could be true. No doubt.
I still say that’s thin science to CONCLUDE those rocks ARE Martian surface ejecta.
I worked in the Life Sciences, not the planet sciences, so this is an honest question — do ‘scientists’ have lots of examples of ejecta from other planets?
Scientists on both sides of the debate (as to whether the sample contains evidence of past life on Mars) agree the rock in question came from Mars.
From NASA:
"The meteorite, called ALH84001, was found in 1984 in Allan Hills ice field, Antarctica, by an annual expedition of the National Science Foundation's Antarctic Meteorite Program. It was preserved for study in JSC's Meteorite Processing Laboratory and its possible Martian origin was not recognized until 1993. It is one of only 12 meteorites identified so far that match the unique Martian chemistry measured by the Viking spacecraft that landed on Mars in 1976. ALH84001 is by far the oldest of the 12 Martian meteorites, more than three times as old as any other.
Many of the team's findings were made possible only because of very recent technological advances in high- resolution scanning electron microscopy and laser mass spectrometry. Only a few years ago, many of the features that they report were undetectable. Although past studies of this meteorite and others of Martian origin failed to detect evidence of past life, they were generally performed using lower levels of magnification, without the benefit of the technology used in this research. The recent discovery of extremely small bacteria on Earth, called nanobacteria, prompted the team to perform this work at a much finer scale than past efforts. "
Alright then, for those of us less astute, please explain how a meteorite broke off of mars and came to earth. Did the planet feel playful and toss a few rocks at Earth hoping to start a game of catch? How could a fully formed planet shed meteorites? Just askin’.
 |
||
| · join · view topics · view or post blog · bookmark · post new topic · subscribe · | ||
 |
||
| · join · view topics · view or post blog · bookmark · post new topic · subscribe · | ||
| Google news searches: exoplanet · exosolar · extrasolar · | ||
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.