by Elsewhere 14 Replies latest jw friends
NASA has announced that they will hold a press conference to announce another significant discovery. The last time they did this they announced that they confirmed the past existence of large amounts of water.
I can't wait to see what the new announcement is about!
Elsewhere,
I started a thread awhile back about "would your faith be challenged if they found pre-life/life on Mars" ....or something like that. About 95% of those posted said it wouldn't phase their beliefs. It would mine.
Gumby
They found these guys demonstrating...
Finding life or past life on Mars wouldn't affect me one way or the other, but the WTS may have to do some flip flopping on the subject of life and how it came to be. Bug
Here is more info....
http://www.space.com/scienceastronomy/opportunity_announcement_040322.html
| NASA to Announce 'Major' Discovery by the Opportunity Mars Rover at 2 p.m. ET By Robert Roy Britt Senior Science Writerposted: 09:00 am ET 23 March 2004 |
Update: First posted March 22
NASA will announce a "major scientific finding" from its Mars rover mission today at 2 p.m. ET.
The announcement will be made at NASA Headquarters in Washington, D.C. and carried live on NASA TV. An article about the discovery will be posted to the SPACE.com home page, also at 2 p.m. ET.
The last time NASA promised something like this involving Mars, the result was the revelation that the Opportunity rover's landing site had once been soaked with water, providing the first evidence gleaned from the surface for past liquid water on Mars.
A spokesperson for NASA told SPACE.com that the big announcement would again involve a discovery by the Opportunity rover and not its twin, Spirit.
The agency did not provide detail regarding the science involved, and the spokesperson would not elaborate.
Rover scientists have said they were eagerly pursuing whether the water that once existed at the rover landing site was groundwater or might have been a lake or ocean. In fact, as of late last week they did not agree on what the most recent evidence revealed.
Experts have said they might learn the answer to that question with further investigation, but that they were not certain the answer would become clear.
One of the scientists that will help present the findings is Dave Rubin, a sedimentologist with the U.S. Geological Survey.
The rock outcropping studied in the shallow depression at the landing site was formed long ago as layers of sediment, scientists have said previously. But they've not yet been able to say how long ago, or for how long water was present.
The persistent presence of water is thought to be a prerequisite for life, though the fact that there was water does not mean there was biology. Biologists say life could work its magic either above or below the ground. But clearly the idea of a Martain lake would capture more public fancy.
All signs point to something important in the announcement, as NASA Administrator Sean O'Keefe will make opening remarks. He is typically not involved in science announcements and did not participate in the previous blockbuster presentation of Opportunity's water discovery.
Other speakers include Cornell University professor Steve Squyres, the principal investigator for the overall rover mission, and John Grotzinger, co-investigator for rover team from the Massachusetts Institute of Technology. Rounding out the presentation will be Jim Garvin, NASA lead scientist for Mars and the Moon, and Ed Weiler, NASA's associate administrator in the Office of Space Science.
Maybe they'll find that intelligent life once existed on Mars but they ruined their atmosphere and died off.
Sabrina
forgive me Jim Oberg, for I have sinned. Avoiding the 'F word' on Mars NASA won't speculate about possibility of fossils, but that doesn't mean others aren'tCOMMENTARY By James Oberg NBC News space analyst Special to MSNBC
People have imagined Mars as an abode of life for so long — centuries at least, probably much longer — that NASA’s recent self-styled “significant” announcement of strong evidence for liquid water long ago was, let’s face it, pretty ho-hum to both space enthusiasts and the general public.
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Sure, intellectually, it really is “significant” that the evidence is now in that there’s a location somewhere off Earth where “life as we know it” could once have survived if it had developed at all. It’s the first, but by no means the last, such location that our explorations will encounter.
But a habitat that’s only “potential” is empty, and leaves an emptiness inside us too. There is a seductive urge to fill that emptiness with imaginations in the suggestive shapes that the rovers have been seeing.
The one that intrigues me most — so far — was referred to by "New Scientist" magazine’s veteran space writer David Chandler with the delicate, neutral phrase, “resembling a piece of curly macaroni.” It’s also been called “the rotini pasta,” and similar gastronomic analogies.
There’s a word for what it might be. Everybody knows it, but it’s too risky to use it lest you get bundled up with the crackpot Martian visions of bunny rabbits, ski jumps, ribbed sandworms, capital letters, and stone faces that have been flooding the Net.
The word is “fossil”. But using it seems to be generally thought of as some sort of Howard Stern impersonation that could get a careless scientist ostracized for life.
Almost saying the forbidden wordNow, twice during NASA’s news conference, scientists danced very close to this line. They had the word on their minds, it seems, and they were determined not to pronounce it. Instead, they talked around it.
With what looked to me with a gleam in his eye, project scientist Stephen Squyres gave some background about the mineralogy in the crater that Opportunity had done its exploring of the bedrock layers.
"What kind of rocks preserve signs of ancient life?” he mused. “Minerals that precipitated from water. They can trap the evidence for that." And the minerals at Opportunity's site are exactly such minerals, the results indicate.
MIT’s Dr. John Grotzinger, in response to a question, cautioned that even on Earth, fossils were very rare in ancient rocks. But he too mentioned off-hand that "these minerals [provide] ideal candidates to be time capsules, to preserve something that was there."
“Fossils are rare in rocks from the era before multicellular life,” a NASA scientist explained to me privately, agreeing that microorganisms would be very difficult to ever find. “But larger fossils are fairly common in more recent strata. If Mars ever had macroscopic life, whether truly multicellular or in the form of large colonies like stromatolytes, fossils would be discoverable with a reasonable search.”
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“This feature has the team in Pasadena squirming,” my old friend told me. “They want it to be an artifact [that is, not ‘real’].”
More recent suggestions are that the curlicue wasn’t rock at all, but something created by the abrasion of the drill.
How long was Mars ‘alive’?There’s one big problem with accepting even the possibility of fossils in Martian rocks: The most recent models of the geologic evolution of Mars don’t allow anywhere near the time spans for life that were needed on Earth to produce recognizable fossils. Here on Earth, there was a more than 2 billion year gap between the first single-cell life and the development of organisms big and hard enough to leave recognizable traces.
Mars didn’t have anywhere near that long. Even if it had been “warm and wet” when young (or even “cold and damp,” as newer thinking suggests), the thicker atmosphere that provided a warming greenhouse effect would be torn away by asteroid impacts and wind-blasted away by a solar wind unconstrained by the planet’s dwindling magnetic field. Once this process was well advanced, the surface would become — and remain — far too cold for any biology.
If there were oceans, or even lakes, they might conceivably have lasted anywhere from a few years to millions or perhaps tens of millions of years – but not hundreds of millions, or even a billion or two. Could they have given birth to creatures that would have left recognizable fossils?
For a quarter of a century, as friend, colleague and co-conspirator, I’ve enjoyed the insights and imaginations of Chris McKay, whose dreams of Mars shaped his entire life. Now a senior planetary geologist at NASA’s Ames Research Center in California, he has long argued that the unique geology of Mars might have allowed a faster path to multicellular life than the one followed on Earth.
Earth’s early living things remained trapped small by the planet’s rapacious devouring of oxygen produced by the organisms. The energizing gas could not accumulate since it was being sucked up by the rocks as they eroded, circulated via plate tectonics, and formed vast seabed deposits. But Mars lacked those processes, and so any early life there could have much more quickly created enough free oxygen to permit the big step up to multi-cellular forms.
The time scale on which this might have happened, at best, seems shorter than the time scale on which any open oceans might have frozen up and eroded away, again at best. Likely? No. But impossible? No, too.
Looking at the picturesUnconstrained by scientific propriety, but still dedicated to testable theories, a number of non-NASA space enthusiasts have tackled the “fossil” theory head-on. One of the more impressive Web sites is “Mars Fossils, Pseudofossils or Problematica?”, by Canadian scientist Michael Davidson.
“If these are fossils, which is not certain but possible, then it is likely these organisms evolved during the watery epoch of Mars ...” he writes. What the rover found, he suggests, is “a marine reef of hard-shelled but eroded organism debris.”
But even in private, most NASA scientists cautioned against overinterpretation of suggestive shapes. “I would be extremely cautious about ascribing biological significance to any features that may be found in the rock,” one told me. “Since the geology is somewhat different than that of Earth, novel geologic features will occur.”
More good advice was provided by Oliver Morton at his blog “MainlyMartian.” Morton, author of "Mapping Mars: Science, Imagination and the Birth of a World,” offered a summary of the press conference that suggested we might indeed find out if there were fossils in the rocks. “Unlikely, but not inconceivable,” he concluded.
“If there are fossils, though,” he continued, “in order to be recognized as such they'll have to meet ‘the Knoll criterion.’” This is named after Andrew Knoll, an expert on fossilized Earth bacteria who is on the mission science team. He is the author of “Life on a Young Planet.”
Morton explains: “The Knoll criterion is that anything being put forward as a fossil must not only look like something that was once alive -- it must also not look like anything that can be made by non-biological means.”
And so far, on Mars, we’ve obviously just scratched the surface on the non-biological surprises that the planet has to offer. So however much we may be tempted by exotic shapes, we aren’t justified in classifying them with what on Earth we can prove were formed by living things.
Fossils? No, at least not yet. But something in “the form of fossils”, with many of the apparent visual characteristics of fossils? THAT’s a concept we can coin a useful word for, and I so propose: the fossiloids of Mars.
source: http://msnbc.msn.com/id/4480097/
http://www.space.com/scienceastronomy/opportunity_sea_040323.html
| Salty Sea Covered Part of Mars: 'Excellent' Site to Search for Past Life By Robert Roy Britt Senior Science Writerposted: 02:00 pm ET 23 March 2004 |
A salty sea once washed over the plains of Mars at the Opportunity rover's landing site, creating a life-friendly environment more earthlike than any known on another world, NASA scientists announced today.
The rover found evidence for the shores of a large body of surface water that contained currents, which left their marks in rocks that developed at the bottom of the sea. Opportunity found a distinct chemical makeup in the rocks and unique layering patterns that must have been generated by slow-moving water in an evaporating sea, researchers said.
The discovery casts fresh light on the possibility that critters could have gained a toehold on the red planet when it was younger, warmer and wetter.
Scientists don't yet know how deep the ocean was, exactly when it existed or for how long.
The finding builds on the March 2 announcement that Meridiani Planum, where Opportunity landed, had long ago been soaked with water. Geologists could not tell from those initial results whether the water was above the surface or only underground.
"We think Opportunity is now parked on what was once the shoreline of a salty sea on Mars," Cornell University's Steve Squyres, principal science investigator for the Mars rover mission, said in a statement provided to SPACE.com prior to a press conference today.
The rocks would be excellent preservers of biological signs, if life ever existed on Mars, Squyres said. That makes Meridiani Planum a prime target for future missions that would search for evidence of past biology.
An ancient sea also implies that early Mars was warmer than today, said University of Colorado geologist Bruce Jakosky, who was not directly involved in the finding. And he said it suggests that any possible microbes on Mars would not have had to rely only on relatively inefficient subsurface, geochemical energy, but might have used direct sunlight as an energy source.
"If it's surface water, that would allow the possibility of photosynthetic organisms," Jakosky told SPACE.com. "Once you can tap into sunlight, it leaves open the possibility for a much greater abundance of life if it was ever there."
Scientists so far have no firm evidence that Mars was ever inhabited, however.
Sedimentary signs
The crucial clues that came together in recent days included the detection of chlorine and bromine, indicating a salty sea had evaporated over time, scientists said. Also significant were crisscrossing layers of sediment in the rock that revealed they formed beneath currents of moving water.
Early interpretations of the same lines of research led to the previous discovery that the rocks were once soaked in water, but it wasn't clear if the water was present when the rocks formed, or if the water came later. Increased confidence in the bromine finding strengthened the case that the particles which formed the rocks had precipitated out of surface water, with salt concentrations that increased as the water evaporated.
Some layers within the rock are at telltale angles to the main layers. Scientists call the patterns "crossbedding." Other features, called festooned layers, involve smile-shaped curves produced by shifting, rippled shapes of loose sediments under a current of water.
The patterns indicate sediment the size of sand grains had bonded together into ripples in water that was at least 2 inches (5 centimeters) deep -- and possibly much deeper, said John Grotzinger, a rover science team member from the Massachusetts Institute of Technology. The water flowed at a rate somewhere between 4 and 20 inches every second (10 to 50 centimeters per second). That's up to about 1 mile an hour.
"Ripples that formed in wind look different than ripples formed in water," Grotzinger said.
The rocks may have been cast in a salt flat that was alternately wet and dry, Grotzinger added. Similar environments on Earth, at the edge of oceans or in desert basins, sometimes have currents of water that produce the type of ripples seen in the Mars rocks.
Brighter prospects
The discovery re-ignited enthusiasm over Mars as a potential well for biology, at least in the past. (Researchers are unsure whether any life that ever developed on Mars -- if it did -- could have endured into the present era, with Mars being cold and dry.)
"The particular type of rock Opportunity is finding, with evaporite sediments from standing water, offers excellent capability for preserving evidence of any biochemical or biological material that may have been in the water," said Squyres, the rover mission's chief scientist.
The discovery quite literally brightens the prospects for past life in another important way.
Had the water been only subsurface, life would have had to rely on geochemical energy, such as the decay of rocks into methane. On Earth, dependence on geochemical energy is a limiting factor for underground microbes, said Jakosky, the University of Colorado geologist who is also director of the university's NASA-sponsored Center for Astrobiology. He helped pick the rover landing sites but has not been directly involved in the science explorations.
Organisms that depend on geochemical energy are less diverse and of more limited scope than life that flourishes in sunlight, Jakosky explained.
"This dramatic confirmation of standing water in Mars' history builds on a progression of discoveries about that most earthlike of alien planets," said Ed Weiler, NASA associate administrator for space science. "This result gives us impetus to expand our ambitious program of exploring Mars to learn whether microbes have ever lived there and, ultimately, whether we can."
Most scientists agree that finding signs of past or present life will likely require sending a robot to bring back samples for study in laboratories on Earth. Meridiani Planum is, for now, the best destination for such a mission, which NASA has slated for launch sometime in the next decade.
"Someday we must collect these rocks and bring them back to terrestrial laboratories to read their records for clues to the biological potential of Mars," said James Garvin, lead scientist for Mars and lunar exploration at NASA Headquarters.
Hints at 'warm and wet' Mars
Finding a sea on Mars also hints at the past climate. Scientists have been arguing for decades over whether Mars was once warm and wet or just wetter and cold.
"I think that this seems to point toward Mars being warm enough and wet enough to allow standing water" in the distant past, Jakosky said.
Jakosky also explained that today's announcement means the water was present as the sedimentary rock formed. The rocks are known to be from Mars' early epochs, so the water was likely there in the very, very distant history of the planet's roughly 4.5 billion years of existence. Had the new evidence pointed only to groundwater altering the chemistry of the rocks, such water might have coursed through the rocks at any time during the planet's history, including well after the rocks themselves were formed.
Opportunity had spent its entire time on Mars, since landing in late January, inside a shallow crater studying soil and the exposed shelf of bedrock. The most recent and telling observations came by taking 152 microscopic pictures of a rock named Last Chance.
The findings add to previous rover discoveries of hematite, a mineral typically formed in water, and the layered rocks being laden with salts, which led scientists to conclude the region was at least soaked with groundwater.
Other investigations from orbiting spacecraft have revealed possible shorelines elsewhere on Mars, but no ground measurements have confirmed any of those findings, and some scientists had remained skeptical that Mars ever harbored any significant surface water.
Scientists have said they see no visible shorelines surrounding the Meridiani Planum, so they can't yet deduce the size of the ancient body of water.
The rover left the crater this week and will now try to examine what scientists think is a larger rock outcropping some distance away. The rover will roam across a vast plain that is, overall, the size of Oklahoma.
At the larger outcropping, researchers hope to find more extensive layers and read them like pages of a history book, to learn more about the depth, breadth and timing of the ocean that long ago graced the red planet.
I watched the program, it was an excellent presentation. The Q&A session was also very good.
Ironically, now the pressure is even greater on the scientific community to find some evidence of life itself on Mars. They must prove that life existed on Mars otherwise the creationists will have a hay day if water existed on Mars but no proof of life is found. Of course both evolutionists and creationists would find a way to explain things and still keep their beliefs intact. They spoke of others missions and seemed to be especially looking forward to the one launching in I believe 2009, landing in 2010, which they hope may take them further down that road to discovering evidence of life.
Whether there was life or not, the truth is what counts and I hope they find that truth.
Sabrina
Maybe this is what they found.
