LEAGUE CITY, TEXAS - Europe's Mars Express spacecraft is casting new light
on the past and present status of the red planet, wowing scientists with an
impressive set of distinctive observations and in some quarters promoting a
tinge of jealousy.
Europe's first and on-going mission to Mars has spotted signs of very recent
volcanic activity along with the vestiges of glaciers and gigantic waterfalls.
Given these and other findings from the Mars orbiting spacecraft, it is not
unreasonable to suggest that life on Mars not only emerged but could have survived
to the present in underground niches.
The latest in Mars Express data and what's ahead for the mission is being shared
between some 1,500 space scientists attending the 36th Lunar and
Planetary Science Conference, held here March 14-18 and co-sponsored by the
Lunar and Planetary Institute and NASA's Johnson Space Center.
"Clearly, thanks to the instruments on Mars Express, we are seeing a new
Mars ... a Mars that we didn't expect," said Bernard Foing, Chief Scientist
of the European Space Agency's (ESA) Science Program. "We have found evidence
of recent volcanism, which is yesterday in the scale of martian history, as
well as very recent glacial activity and ice deposits."
Foing told SPACE.com that some people thought Mars volcanism is dead.
"No, it could start up again tomorrow," he said.
Operating in orbit around the red planet for more than a year now, ESA's Mars
Express data confirms that Mars was wet and possibly warm very early in its
history. Extended amounts of liquid water were present, Foing said. But with
the erosion of the martian atmosphere, the last three billion years have left
Mars cold and dry, he said.
Look globally and locally
What is important now, Foing added, is to identify what niches life on Mars
could have retreated to and then survived within for the last three billion
years.
Mars Express has found levels of methane in the planet's atmosphere. These
measurements are puzzling, Foing said, and could be interpreted as the possible
signature of life on Mars today.
"We did not expect to have it," he said, "so it's a discovery."
Another cause of the methane could be from the presence of active volcanism.
Indeed, Mars Express is prodding scientists to consider currently active volcanism
in terms of thermal vents that could serve as comfy niches for potential ecosystems.
"Because Mars has a large variety of potential habitats for life, there
is need for follow-up measurement to better understand Mars globally and also
locally," Foing said.
Grasping the data: long, hard haul
While on one hand there is excitement regarding the Mars Express findings,
there is also a "not so fast" feeling drifting through the conference
here.
There is a bonanza of data being churned out by dual Mars rovers - Spirit and
Opportunity - as well as two U.S. orbiters, the Mars Global Surveyor and Mars
Odyssey.
"I don't think there's ever been a time where we've had this much information
about Mars coming down at once," said Matt Golombek, a Mars geologist at
the Jet Propulsion Laboratory in Pasadena, California.
"I see some things beginning to emerge," Golombek said. "But
there's so much information coming down now that we're just trying to grapple
with it." It's not the first time. With the Viking missions, a 1970's Mars orbiter/lander
program, "it almost took 10 years to get our arms around what that data was
trying to tell us."
Similarly, the newly gained Mars Express data will take time to calibrate and
decipher what the instruments are telling the scientific community, said Joseph
Boyce, on the research faculty at the Hawaii Institute of Geophysics and Planetology,
University of Hawaii at Manoa in Honolulu.
"But right now, what you see initially is pretty spectacular," Boyce said.
"The images are absolutely incredible. They've done a good job."
The European community has arrived
One Mars Express instrument still to be activated also promises to yield unique
data. In May, the spacecraft is due to activate its Sub-Surface Sounding Radar
Altimeter (MARSIS). It will look for signs of frozen ice underground, as well
as search for reserves of liquid water.
The Mars Express is already producing data that you can take to the bank, with
other payoffs yet to come, said Ray Arvidson, the Mars Exploration Rover mission
deputy principal investigator of Washington University in St. Louis, Missouri.
He is also a U.S. collaborator on the Mars Express visible and near infrared
mapping spectrometer - called OMEGA -- designed to provide the mineralogical
and molecular composition of the surface and atmosphere of Mars.
"I look at it as the European community has arrived," Arvidson noted.
As for the detection of methane, and speculation about its origin, Arvidson
said: "I think it will be controversial for years...but it's exciting. I
think that measurement will probably stand ... but the interpretation will be
subject to scrutiny for a long time."
Credibility gap?
Within the next few weeks the Mars Express data will be distributed widely.
"It will take a while for everything to filter down to the U.S. community,"
Arvidson advised, "so they can look at the same data sets themselves and
come to the same conclusions and then go on to other new conclusions."
Arvidson underscored not only the success of Mars Express, but also ESA's SMART-1
lunar orbiter now orbiting the Moon, and the recent landing of the European-supplied
Huygens probe on Titan, a moon of Saturn.
"They are pumped up and rightly so," Arvidson said. "It bodes
well for the independent future of Europeans exploring the solar system and
also for joint activities."
In some scientific circles, however, there have been subtle jabs at the Mars
Express team for hyping data and making claims as firsts that don't deserve
such a label. In essence, the specter of a credibility gap has been chatted
about.
"I think that's just a few people," Arvidson said. "The not-invented-here
[in the U.S.] is a little bit of the shock effect of seeing all these new data
from people whose primary language is not English."