NASA - National Aeronautics and Space Administration

By: Jim Hodges

Michael Mumma asked the question: "Methane on Mars – Geology, Biology, Neither or Both?" on Tuesday at the Reid Center.

Then he answered that there is no answer … yet.

"Much follow-up work is needed to address this fundamental question," Mumma told the NASA Langley April Colloquium crowd.

A team led by Mumma, senior scientist in the Solar System Exploration Division at Goddard Space Flight Center, announced the discovery of plumes of methane on Mars last fall, during a symposium on the planet in Williamsburg. The discovery gained wider circulation when a group of newspaper and magazine articles in January followed a paper online in the online version of Science magazine.

A team led by Michael Mumma determined that there is methane on Mars, and that its release is seasonal and from specific locations. But questions remain as to its source. Credit: NASA/Sean Smith

Click image to enlarge

The group showed through spectrometer readings taken with powerful telescopes, such as those at the W.M. Keck Observatory in Hawaii, that methane is present at several locations on Mars and that its emissions are more pronounced during the planet's summer.

The quest now is to find the other gasses that will better define the origin of the methane and verify the seasons.

For example, if ethane and/or propane are found, the source is the methane is probably geology. If ammonia and/or nitrous oxide is present with the methane, the answer is probably biology, indicating life could well exist on Mars.

"And why is it released only annually, instead of continuously?" Mumma said. "There are several possibilities that could explain that."

But the issue, at least for now, is research time with a telescope powerful enough to get the spectroscopy readings available from as many as 12 chemicals on Mars. And, when the time is available, the variables of weather on Earth and on Mars both are issues.

And then the issue is better defining the region on Mars from which the methane originates. The discovery of methane by Mumma's team was done on a 400 kilometer scale. He's hoping to reduce that to 30 kilometers, using adaptive optics.

"We want to know, are there local places?" he asked. "I mean, local vents, on the scale of meters. Or do we only see methane released from a general area, 400 kilometers in size, representing a wide-spead release in the soil."

And then the issue is mapping that region.

"We can't do the ultimate measurements from ground-based observing," Mumma said. "We have to have a mission to Mars that maps the whole planet every day for two years with high, special resolution on the surface."

He laughed slightly, then offered, "What about an airplane? Would that do the job?"

Mumma was jibing his Langley host, Joel Levine, who is the chief scientist on ARES, the Mars airplane developed and tested on the center, but yet to be selected by NASA for a mission.

"I think it would," Mumma said.

And after ARES, a lander needs to go to Mars. The Mars Science Laboratory is scheduled to go in two years, and it will have the ability to detect methane. But the question remains where to land it?

Mumma wonders if the order of the missions ahead needs to be reconsidered.

"This is not something I thought of 15 years ago or 10 years ago or two years ago," Mumma said. "This is based on discovery of the active vents (of methane)."

The process would take years, given the economic climate.

"Economically, it's only $2 billion for all three missions," Mumma said. "That's a bargain for anybody's checkbook."

At stake is the value of a potential Mars landing by humans, scheduled roughly for the 2030 time period. Mumma said Tuesday that human exploration is not being considered in his group's work but acknowledged that NASA's human space exploration program could benefit by the Mars scientists.

"The issue of what humans should do when they go to Mars is still open," he said. "I was quite surprised to learn … that the initial human missions to Mars are supposed to avoid any sites where biology might exist. The intent is to avoid what is known as 'forward contamination.' "

And so, missions suggested by Mumma could determine where that biology might exist, where humans should not go.

"When you think about this, it changes your mind about what we should do in advance of humans going to Mars. It's a very important question … and I believe that the sequence of events I have outlined can determine" the answer.


 
NASA Langley Research Center
Managing Editor: Jim Hodges
Executive Editor and Responsible NASA Official: H. Keith Henry
Editor and Curator: Denise Lineberry