MARS HAS WET SPOTS IN GULLIES, RESEARCH SHOWS WASHINGTON -- Researchers using NASA's
Mars Global Surveyor spacecraft announced Thursday that they found puzzling signs of water seeping into what appear to be young, freshly-cut gullies and gaps in the Martian surface.The startling discovery of recently-formed, weeping layers of rock and sediment has planetary experts scratching their heads.
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The wet spots show up in more than 120 locations on Mars and in the coldest places on the planet, said Michael Malin of Malin Space Science Systems in San Diego, California, which built the spacecraft's camera.
And that presents a "perplexing problem," he said, because logic says that Mars sub-zero temperatures and thin atmosphere should have kept those wet spots from ever forming.
Most are in the Martian southern hemisphere and usually appear on slopes that get the least amount of sunlight during each day. They appear only at latitudes between 30 and 70 degrees. On Earth, that zone would stretch from New Orleans, Louisiana, to Point Barrow, Alaska, in the northern hemisphere and from Sydney, Australia to much of the Antarctic coast in the south.
The wet spots, which turn up in 200 to 250 different images from the Global Surveyor spacecraft, "could be a few million years old but we cannot rule out that some of them are so recent as to have formed yesterday," Malin said. He and colleague Kenneth Edgett detailed their findings at a news conference at NASA Headquarters after Science magazine
rushed their scientific paper into public release."We were quite surprised and confused" to find present-day evidence of water, Malin said, "because it doesn't really fit our models of what Mars is like."
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The best explanation for the presence of water is that repeated outbursts of
water and debris may occur on Mars, similar to flash floods on Earth."This story, I don't believe, will be answered until someone goes with a pick and shovel" to actually chip away at the landforms, Malin said.
Edgett, who is poring over the 65,000
images the spacecraft has returned since it arrived at Mars in 1997, could come up with no better explanation.
Michael Malin (left) of Malin Space Science Systems, seated next to colleague Kenneth Edgett. Malin and Edgett penned the scientific paper about the recent discovery of water on Mars.
"I was dragged kicking and screaming to this conclusion...Mars is like nothing we thought Mars was going to be like before this camera got there. It's not your mother's Mars," Edgett said.
The water supply is believed to be about 300 to 1,300 feet (100 to 400 meters) below the surface and limited to specific regions of Mars, according to a NASA release. Each flow that came down each gully may have had a volume of water enough to fill seven community-sized swimming pools or sustain 100 households for a month.
What Malin and Edgett found is "very intriguing" and holds "profound implications" for the possibility of finding past or present
life on Mars, said Ed Weiler, NASA space science chief.But the data still must undergo further scientific scrutiny. "In science you have to prove your hypothesis and there's a lot of work to be done," Weiler said.
NASA's space science chief Ed Weiler
He cautioned against jumping to conclusions. "They have not found lakes or rivers flowing on Mars. They have not found hot springs. They certainly have not found hot tubs with Martians in them...We are not saying we have found life on Mars," Weiler said.
But the finding does appear to have pushed forward the theory of when Mars -- once wet and warm -- might have lost all its water. The latest find could "set that clock back to perhaps a million years ago, perhaps a thousand years ago, perhaps yesterday," Weiler said.
The release of the research paper and the hastily-prepared news conference came after the discovery -- reported
two days earlier on SPACE.com -- triggered a blitz of news coverage about water on Mars. The scientists told NASA a month ago of the startling images, which were taken in January.
NASA's press conference about Mars
Most of the wet spots were found on the walls or central peaks of impact craters. Others turned up on the walls of "distinctive pits" in the south polar regions. Still more were discovered on the walls of two major Martian channel systems, Nirgal Vallis and Dao Vallis.
The "most striking" features found in these locations were "entrenched, steep-walled, V-shaped channels" that appear to be cut by water action within the gullies, the paper said.
This chart, presented at the Mars press conference Thursday, shows details of a Martian crater wall that has features formed by water.
Science
magazine will publish the Malin-Edgett paper in its June 30 issue. But the article was released on Thursday, two days after SPACE.com reported that scientists had found "seasonal deposits" of water from springs on the Martian surface. That, along with other reports, triggered a flurry of broadcast and print reports around the world. The barrage of publicity in turn prompted NASA to move up by a week its scheduled June 29 press conference to counter what it called "incorrect" accounts of the discovery.
If the findings can be confirmed, "it means Mars is not geologically dead," said Wes Huntress, NASA's former space science chief and now director of the Geophysical Laboratory, Carnegie Institution of Washington.
"We knew that there's really water below the surface but we didn't know where it was," he said.
Global Surveyor was launched in 1996 to make a detailed map of Mars with a suite of instruments designed to provide new details about the planet's craggy surface. With the latest find, the spacecraft has surpassed scientists' expectation, said Huntress, who oversaw its development.
"To find water is the holy grail of orbital reconnaissance," he said.
But scientists caution that finding water isn't a valid reason to rush into a decision to send humans to the planet. The discovery first requires confirmation and then should be studied much better by a series of spacecraft both orbiting the planet and landing on its surface.
"I don't think this is a signal to send humans to Mars right away but it does confirm that Mars is the right target to explore," Huntress said. "If water really is there and it's readily accessible, it becomes the place to set up a
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