Mars Images Reveal Recent Volcanic/Glacial Activity

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Fire and Ice: Mars Images Reveal Recent Volcanic and Glacial Activity

Mars isn't as sleepy as scientists suspected. An international

research team, which includes Brown University planetary geologist

James Head, has found evidence of recent glacial movement and

volcanic eruptions in 3-D images from the Mars Express mission. The

team's latest work, laid out in three Nature papers, also includes

evidence of a frozen sea close to the equator. These and other Mars

Express findings are stoking debate about the possibility of life on

the Red Planet.

 

 

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http://www.brown.edu/news/2004-05/04-097.jpg

 

PROVIDENCE, RI — Shifting glaciers and exploding volcanoes aren't

confined to Mars' distant past, according two new reports in the

journal Nature.

 

 

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Mars is very dynamic.

The shape and flow of this deposit near a Martian mountain almost 4

km. tall suggests ice-rich glacial movement. The image, taken on the

eastern rim of the Hellas Basin, was made by the Mars Express High-

Resolution Stereo Camera.

Photo: European Space Agency

 

 

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Glaciers moved from the poles to the tropics 350,000 to 4 million

years ago, depositing massive amounts of ice at the base of

mountains and volcanoes in the eastern Hellas region near the

planet's equator, based on a report by a team of scientists

analyzing images from the Mars Express mission. Scientists also

studied images of glacial remnants on the western side of Olympus

Mons, the largest volcano in the solar system. They found additional

evidence of recent ice formation and movement on these tropical

mountain glaciers, similar to ones on Mount Kilimanjaro in Africa.

 

In a second report, the international team reveals previously

unknown traces of a major eruption of Hecates Tholus less than 350

million years ago. In a depression on the volcano, researchers found

glacial deposits estimated to be 5 to 24 million years old.

 

James Head, professor of geological sciences at Brown University and

an author on the Nature papers, said the glacial data suggests

recent climate change in Mars' 4.6-billion-year history. The team

also concludes that Mars is in an "interglacial" period. As the

planet tilts closer to the sun, ice deposited in lower latitudes

will vaporize, changing the face of the Red Planet yet again.

 

Discovery of the explosive eruption of Hecates Tholus provides more

evidence of recent Mars rumblings. In December, members of the same

research team revealed that calderas on five major Mars volcanoes

were repeatedly active as little as 2 million years ago. The

volcanoes, scientists speculated, may even be active today.

 

"Mars is very dynamic," said Head, lead author of one of the Nature

reports. "We see that the climate change and geological forces that

drive evolution on Earth are happening there."

 

Head is part of a 33-institution team analyzing images from Mars

Express, launched in June 2003 by the European Space Agency. The

High Resolution Stereo Camera, or HRSC, on board the orbiter is

producing 3-D images of the planet's surface.

 

These sharp, panoramic, full-color pictures provided fodder for a

third Nature report. In it, the team offers evidence of a frozen

body of water, about the size and depth of the North Sea, in

southern Elysium.

 

A plethora of ice and active volcanoes could provide the water and

heat needed to sustain basic life forms on Mars. Fresh data from

Mars Express – and the announcement that live bacteria were found in

a 30,000-year-old chunk of Alaskan ice – is fueling discussion about

the possibility of past, even present, life on Mars. In a poll taken

at a European Space Agency conference last month, 75 percent of

scientists believe bacteria once existed on Mars and 25 percent

believe it might still survive there.

 

Head recently traveled to Antarctica to study glaciers, including

bacteria that can withstand the continent's dry, cold conditions.

The average temperature on Mars is estimated to be 67 degrees below

freezing. Similar temperatures are clocked in Antarctica's frigid

interior.

 

"We're now seeing geological characteristics on Mars that could be

related to life," Head said. "But we're a long way from knowing that

life does indeed exist. The glacial deposits we studied would be

accessible for sampling in future space missions. If we had ice to

study, we would know a lot more about climate change on Mars and

whether life is a possibility there."

 

The European Space Agency, the German Aerospace Center and the Freie

Universitaet in Berlin built and flew the HRSC and processed data

from the camera. The National Aeronautics and Space Administration

(NASA) supported Head's work.