Posted on 05/28/2002 10:32:52 AM PDT by RightWhale
Water Ice Discovery on Mars May Be 'Tip of an Iceberg'
By Robert Roy Britt Senior Science Writer
posted: 10:15 am ET 28 May 2002
Scientists are reporting this week detailed evidence for vast amounts of water ice just beneath the surface of Mars. The finding, which confirms preliminary data released earlier this year, should help answer an age-old question regarding where ancient Mars' water went, and it is likely to fuel greater interest in probing the Red Planet for signs of life.
The new data, provided by the Mars Odyssey spacecraft, will be reported in Friday's issue of the journal Science. The findings were embargoed for release Thursday afternoon, but some news outlets in the U.S. and Britain reported on them last week and over the weekend.
The journal lifted the embargo this morning.
The researchers report they have extensive data confirming a layer of hydrogen across much of the planet within 3 feet (1 meter) the dusty surface of both hemispheres -- well within reach of robots or humans who might venture to Mars. The scientists believe the hydrogen is strong evidence for water ice, a finding they first announced in March. The ice would be locked in pores of rock and pockets of soil.
Tip of an iceberg
"The results, even after only a month of mapping observations, are stunning," writes James Bell of Cornell University in an accompanying analysis for the journal. "Separate lines of evidence suggest a loose and/or porous regolith [soil] that could exceed a kilometer or more in thickness, implying that the subsurface ice detected by Odyssey may represent only the tip of an iceberg frozen underground."
The highest concentrations of water ice may be 1-3 feet (30-60 centimeters) below the surface from the edge of the polar ice caps to mid-latitudes of 60 degrees, the scientists say. In March, they had not yet collected data on the planet's northern hemisphere.
Odyssey, which arrived at Mars last fall, measured neutrons and gamma rays escaping from the Martian surface, finding signs that hydrogen is present in several pockets of the Martian crust. Hydrogen is one component of water but can exist alone and as a part of other substances; even the newest data will be subjected to further verification, the researchers say.
Scientists are very optimistic about the quantities of water. The data suggest that 20 to 35 percent of the weight of the ice-bearing layer is water ice, filling in most of the pores of a loose jumble of dust and broken rock.
Further, the researchers speculate that though their instruments cannot detecting anything deeper than about about 3 feet (1 meters), other geologic evidence suggests the reservoir may extend .62 miles (1 kilometer) deep or more.
"There's a lot of ice on Mars," University of Arizona researcher William Boynton stated back in March, when initial findings were released. "We really have a whopping large signal."
Boynton, lead author on one of three papers that will be published in Science, is the principal investigator for the Gamma Ray Spectrometer suite of instruments, used to make the discovery. Another instrument, called a Neutron Spectrometer, was also employed.
Ingredients of life
Biologists say liquid water is essential for life as we know it. But frozen water near the surface of Mars may be a remnant of past liquid oceans, which might have existed millions or billions of years ago when researchers believe Mars was warmer and may have harbored a thicker atmosphere.
Researchers have cited canyons and river-like features as evidence.
Scientists already knew there was water locked up in the northern ice cap, along with carbon dioxide ice. But finding water ice away from the permanently frozen polar caps would greatly boost the chances that it might melt seasonally or at least periodically, or that pocket of underground water might exist and could therefore potentially support life.
For water to exist in underground pools, some internal heat source would be needed. Though Mars appears volcanically inactive to the eye, researchers say there could be magma inside the planet and it would be a source of heat that could melt ice.
Scientists have also said fossils could be locked up in the Martian soil. Dormant life might remain in the ice -- something researchers have found to occur on Earth.
Many leading researchers believe only by putting humans on Mars will they be able to answer these questions. NASA has been reluctant to commit to any sort of timetable for such a mission. But speculation of such a mission -- either by NASA or by Europeans -- now runs rampant.
Speculation: Mission to Mars
As a result of the finding, "NASA may now commit itself to a manned landing within 20 years," according to a story on the BBC's web site. That claim was not attributed to any official and has not been verified. Other published reports carried similar unsubstantiated claims.
If NASA did commit to a timetable for putting humans on Mars, it would be a stark shift in policy. The agency has said that not enough is known about the hazards on Mars, including potentially lethal radiation, to make firm plans. Odyssey also caries an instrument designed to measure the radiation environment, but no results from that device have been announced.
Water at mid-latitudes on Mars, even if frozen, would make a crewed mission more practical by providing a source of drinking water. More important, it could also be broken down into hydrogen, for rocket fuel, and oxygen.
Odyssey's Gamma Ray Spectrometer will be extended further from the orbiting, $300 million spacecraft in coming weeks, which should provide better measurements of hydrogen and other chemicals on and under the surface of Mars. The instrument measures the speed of neutrons bouncing off the surface and near surface. Neutrons that have hit hydrogen atoms move more slowly.
The results will be "used to guide the selection of landing sites for future rovers and landers, sample returns, and eventual human exploration," Bell said. "In that sense, the most important implications of the detection of subsurface water ice deposits on Mars may not be realized for decades. It is likely to be worth the wait, however."
The lead authors of the other papers are William Feldman of Los Alamos National Laboratory and Igor Mitrofanov of the Space Research Institute in Moscow. NASA had planned a press conference for this Thursday to discuss the findings, according to unconfirmed press reports.
Odyssey launched April 7, 2001. The spacecraft is 7.2 feet (2.2 meters) long, 5.6 feet (1.7 meters) tall and 8.5 feet (2.6 meters) wide. It will study Mars for at least three years from 249 miles (400 kilometers) above, mapping the planet in visible and infrared light in unprecedented detail, scientists say.
Looks like a joint mission to Mars will be proposed, Russia and America with America paying the bill. ESA and NASDA might join in with their usual token contributions. China has already said they are going to Mars eventually, so perhaps the race is on.
You all got your resumes updated? NASA may be hiring. Won't be me, though, somebody has to stay behind to keep the moose browse shrubs in the yard trimmed and orderly.
However, IMHO, we should should not go to Mars in partnership with Russia. They are unreliable and hopelessly corrupt. In the end, if we do enter into a parntership with them, the Russians will hold us back, as they did with the ISS -- and as they did with their own country these past 100 years.
It might be that a geosynch base [22,000 miles high earth orbit] will be built as an intermediate step, and a base on the moon will be developed to gain the necessary experience before they embark to Mars.
Total Recall. Enclosed cities.
As for this making a manned Mars mission "a certainty," that is a ludicrous assertion, obviously made by some media nitwit who actually believes NASA press releases. It still costs > $ 100 B and a decade (or more) to send people to Mars. Anybody here think such a sum is likely to be forthcoming? If so, I have some swampland and a bridge to sell you.
In short, no news here. Nothing to see. Move along.
Nope, sorry. Of the ~ $13 B budget, about $ 8 B goes to STS (shuttle) operations; the trip from Earth to LEO is the first step, so that's a recurring cost, not a disposable one. Even if we abandoned ISS, we would still need ~ $ 10-12 B per year, in addition to the current NASA budget to fund the program. Believe it or not; these numbers have been cooked over and over again for the last 20 years. the answer always comes out the same (or more).
And Who -- it may not be NASA.
Finding an ocean of subsurface ice -- which is not old news
They haven't found "an ocean" -- they've found extensive buried water ice. The "ocean" part is an interpretation; nobody knows how thick this ice layer is.
-- can only serve to move that date up.
Because???
Why geosynchronous? What would be the advantage?
If you're relying on chemical rockets, the crew support requirements are prohibitive. However, a VASIMR engine or a nuclear rocket could get you there much more quickly, thus reducing the support requirements while increasing the cargo capacity.
Secondly unless they rid in a ship composed of at least 5 inches of lead, the cosmic radiation their ship would be exposed to would kill them in a couple of months.
You don't need any shielding. Protect the crew the way the Earth does it, by using magnets.
Dream on about Terraforming this planet. The idea of using greenhouse gases to heat it up are Science Fiction just as the Global Warming crowd have been proven wrong time and time again!
Are you suggesting that the greenhouse effect doesn't work? It does, whether or not it is responsible for recent changes in the Earth's climate.
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.