Spotlight on Research: Studying the Skies over Mars
Posted: July 7, 2004 at 1:00 am, Last Updated: November 30, -0001 at 12:00 am
By Lynn Burke
When Mike Summers, professor of planetary science and astronomy, was 10 years old, one of his neighbors had a remote-controlled plane. Summers wanted one in the worst way, but his family couldn’t afford it. Now, he has a remote-controlled plane—and it is out of this world.
The plane is the major component in NASA’s Aerial Regional-scale Environmental Survey (ARES) project, a Mars scout mission. Summers is a co-investigator on the project in which a plane will be dropped into the Mars atmosphere sometime around 2011 to gather data on the planet’s crustal magnetism, atmospheric chemistry, and mineral and geology. The mission should provide data that will help fill the gap between the limited resolution data of the Mars Orbiter missions and the very detailed but very local data coming out of the current Rover missions.
“The ARES plane will be folded into a four-foot-diameter canister that will be launched to Mars,” says Summers. “When it gets close to the planet, the canister will drop into its atmosphere. A parachute will then yank the plane out of the canister and cause it to unfold. Then, rockets will take over, the parachute will be cut, and the self-controlled plane will fly around a preprogrammed path.” Unfolded, the plane will have a wingspan of about 20 feet.
An artist’s conception of the ARES plane.
The mission is still in the developmental stage, but tests of a half-size prototype over Oregon have been very successful, says Summers. “The test was so flawless that we could have just folded up the airplane and taken it back up and flown it again,” he says. Video of the test flight and other mission information can be viewed on the ARES web site.
Summers’ goal is to help the team define what the Mars atmosphere is like in terms of winds, temperature, and pressure, thus developing a weather forecast model for the planet. He also will study the composition of the atmosphere. “In the cone of the plane, we’re going to have a mass spectrometer,” says Summers. “As the airplane flies along, gases from the atmosphere will go through a tube and be measured.”
Summers was invited to join the ARES mission after a paper of which he was the lead author was published in Geophysical Research Letters in 2002. The paper discussed how the presence of methane in the Martian atmosphere could be a biomarker of subsurface life on Mars. Now, the recent discovery of methane in Mars’ atmosphere by three separate research teams has made the already exciting ARES mission even more thrilling for Summers. He explains that methane’s importance comes from the fact that the combustible mix of oxygen and methane gives the gas a short chemical lifetime. Mars’ carbon dioxide atmosphere would cause methane to oxidize, so any methane in the Mars atmosphere would have to have been put there recently.
“It’s hard to believe that you can get so excited about a gas,” says Summers, “but methane is biogenic and could be the first indication of life on Mars.” On Earth, one source of methane is bacteria, some of which can exist in extreme conditions, such as high saline, intense heat, or intense cold environments. In rocks miles underneath the Earth’s surface are bacteria called chemolythophiles, which are possibly the oldest bacteria on Earth and one of the first, if not the first, form of single cell life on Earth, says Summers. These bacteria live off the chemical bonds that make up the rocks and produce methane. “Could that be what we are seeing on Mars? Many of us think this is a real possibility,” he says.
Summers speculates that perhaps the bacteria originated billions of years ago on Mars’ surface when the planet had water, evidence of which has been found by the recent Rover missions, and migrated underground as the environment on Mars became too hostile for them. Then again, Summers admits that the methane may be coming from sources other than bacteria, including volcanism, very deep hot water environments that could produce methane by chemical interactions with the rocks, or methane that was trapped when Mars formed billions of years ago.
During the ARES flight, the researchers will sample for methane over different parts of the planet. “By mapping the methane amounts in the atmosphere, we can then determine where it is coming from,” Summers says. “Seeing whether the source is biological is a bit more tricky, but there are ways of doing it.”
Summers also is working on two other major research projects: an Earth satellite mission to study high altitude clouds and climate called AIM and a Pluto mission called New Horizons. “Any one of these projects would be the highlight of a career,” he says, “but to be working on all three is a bit overwhelming.”