Three billion years ago, Earth was a very different place.
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More Evidence for Ancient Water on Mars
Three weeks ago the Mars science team announced evidence of aqueous chemical alteration of a rock outcropping in the Meridiani area of Mars. This evidence suggested that the rocks had either formed in a wet environment of subsequently been altered by liquid water percolating through the soil. Now the team has new evidence to suggest that these rocks were formed on the floor of a lake or shallow sea, where currents created distinctive ripple patterns called crossbedding. These are thus shown to be true sedimentary rocks, in contrast to the majority of rocks on the surface of Mars, which have ...
March 23, 2004 • Posted by: Shige Abe • Report issue
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Surviving With - and Without - Oxygen: An Interview With Christopher Chyba
Without oxygen, animal life on Earth would not be possible. But Earth’s atmosphere wasn’t always rich in oxygen.
March 22, 2004 • Posted by: Shige Abe • Report issue
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When Did Earth's Oceans Become Oxygenated?
Life on Earth has been modifying the environment for billions of years. Green-plant photosynthesis was essential for the development of our current oxygen-rich atmosphere. The history of increasing oxygen in the atmosphere and ocean is complex, however, and significant free oxygen has been available in the atmosphere only during the past 2.2 billion years. Now new measurements by University of Rochester geochemists have uncovered evidence that even after 2.2 billion years ago, the amount of oxygen in the oceans remained low, perhaps up to the time when multicelled life began to proliferate a few hundred million years ago ...
March 08, 2004 • Posted by: Shige Abe • Report issue
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Evidence of Water Found on Mars
NASA’s Opportunity rover has found convincing evidence that large quantities of water were once present in at least one location on Mars. “The rocks here were once soaked in liquid water,” said Steve Squyres, principle investigator for the Mars Exploration Rover (MER) mission, referring to the bedrock outcrop near the rover’s landing site in Meridiani Planum. Evidence suggests that, at some point in Mars’s past, water was present in sufficient quantity to make the region “capable of supporting life as we know it.”
Confirmation of water’s role came from a series of detailed measurements made over the ...
March 03, 2004 • Posted by: Yael Kovo • Report issue
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Evidence for Ancient Water on Mars
In a press conference today at NASA Headquarters, the Mars rover team described evidence that the Meridiani Planum region of Mars was once wet and perhaps “habitable.” The presence of ancient liquid water on Mars has frequently been inferred from large-scale landforms that appear to show water erosion, and ice is an important part of the martian polar caps. However, this is the first time chemical evidence for water has been found in the equatorial regions of the planet, which are the most accessible to spacecraft investigation.
The chemical evidence for past water was found in an outcropping of ...
March 02, 2004 • Posted by: Shige Abe • Report issue
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Can People Go to Mars?
Space radiation between Earth and Mars poses a hazard to astronauts. How dangerous is it out there? NASA scientists are working to find out.
February 29, 2004 • Posted by: Shige Abe • Report issue
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Into the Briny Deep - Perhaps
Opportunity has been getting the lion’s share of the attention in recent weeks, because its twin sister Spirit has been engaged mostly in long-distance driving. But it may be about to steal the spotlight. For several sols, Spirit has been working its way towards nearby Bonneville crater. But even before it gets there, the mobile robot may make a critical discovery. It may find evidence of liquid water on Mars.
Well, not exactly liquid water. Liquid brine, actually. Brine is water that contains dissolved salts. The salts lower the melting temperature of the mixture so that it remains liquid well ...
February 22, 2004 • Posted by: Yael Kovo • Report issue
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Could Opportunity Find Life on Mars?
Interview with Andy Knoll: Part II
Henry Bortman had the chance to talk with Andrew Knoll, a science team member for the Mars Exploration Rover missions and Fisher Professor of Natural History at Harvard University.
Astrobiology Magazine (AM): One of the intriguing aspects of Rio Tinto as a research site is that even though the water in the river is highly acidic, there are bacteria living in it. When you look at the ancient hematite deposits in that region, do you see fossil bacteria?
Andrew Knoll (AK): Yes, you do. In fact, one of the things that attracted me to ...
February 04, 2004 • Posted by: Yael Kovo • Report issue
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Mars Rover on Track of Watery Mineral
The Mars rover Opportunity, which rolled off its landing platform onto the Martian surface early on Saturday, has returned its first real science data to Earth.
February 04, 2004 • Posted by: Shige Abe • Report issue
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First Images of Opportunity Site Show Bizarre Landscape
NASA’s Opportunity rover returned the first pictures of its landing site early today, revealing a surreal, dark landscape unlike any ever seen before on Mars.
January 25, 2004 • Posted by: Shige Abe • Report issue
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Two for Two
Opportunity mission engineers reported at 9:06 pm PST Saturday night that the spacecraft had landed successfully on the Martian surface.
Opportunity descended through the martian atmosphere, then bounced and rolled to a stop exactly according to plan. Three weeks earlier, Opportunity’s twin sister, Spirit, also landed flawlessly.
Unlike Spirit, however, Opportunity came to rest on its side. Although the preferred landing orientation is right-side-up – Spirit landed this way – the rovers were designed to accommodate landing on any of their four sides.
While former Vice President Al Gore and California Governor, Arnold Schwartzenegger, looked on from the Jet ...
January 24, 2004 • Posted by: Yael Kovo • Report issue
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Spirit Scientists Plot a Course
The Spirit navigation team has figured out precisely where the rover landed and mission scientists are ready to go exploring.
“We know where we are now,” announced MER Principal Investigator Steve Squyres Tuesday. “And we also know where we’re going.”
Mission engineers expect the rover to roll down off its landing platform onto the martian surface late Wednesday night.
The first thing Spirit will do after getting all six wheels on the ground is sample the soil in the immediate vicinity of the landing platform. Once that task is complete, Spirit will head out toward a nearby crater ...
January 13, 2004 • Posted by: Yael Kovo • Report issue
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There's History in Them Thar Hills
Although it will be several more days, perhaps as much as a week, before Spirit engineers certify that the rover is ready to leave the safety of its landing platform and go exploring, scientists have already begun to make a list of places they’d like to visit. A cluster of distant hills to the east are high on their list.
“We certainly want to characterize the deposits in the immediate vicinity of the lander as soon as we’re off and roving,” says Ray Arvidson, deputy principal investigator for the MER missions. The next step will be to examine some ...
January 08, 2004 • Posted by: Yael Kovo • Report issue
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Location Is Everything
Within 24 hours after Pathfinder landed on Mars in 1997, NASA scientists had pinpointed its landing site. Spirit’s story is a bit different. Spirit landed six days ago, but scientists are still struggling to figure out exactly where.
According to Matt Golombek, who is leading the effort to tie down Spirit’s location, different groups of scientists working on the problem agree to within about 500 meters (about a quarter of a mile). But, says Golombek, “that’s really not good enough. I want to get it down to 50 to 100 meters” before Spirit starts driving across the landscape.
One problem ...
January 08, 2004 • Posted by: Yael Kovo • Report issue
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Interview With Nathalie Cabrol
asadena, Spirit Mission Sol 4
In this interview with Astrobiology Magazine’s managing editor Henry Bortman, conducted just after NASA released the first high-resolution color picture of Gusev on January 6th, Cabrol talks about her historic interest in the site and what stories she thinks Gusev Crater might have to tell about Mars.
Astrobiology Magazine (AM): When you look at the first color Pancam image of Gusev Crater, as a geologist, what do you see?
Nathalie Cabrol (NC): You see a flat plain. And you see different populations of rocks. This means that it’s a diverse site and has a very ...
January 07, 2004 • Posted by: Yael Kovo • Report issue