Michael Mumma, lead NASA scientist behind the infrared telescope that first discovered the presence of atmospheric methane on Mars in 2003, recently told Seeker that instruments aboard the Indian Space Research Organization (IRSO) Mars Orbiter are inadequate for measuring the planet’s methane.
"The engineers know how to build a good instrument. That's not the issue. The problem is they didn't have the scientific guidance needed to tell them exactly what they needed to do," Mumma said, adding that while the news is "really unfortunate," the sensor can still can be useful for tasks such as measuring the planet’s reflected sunlight.
The spectrometer can pick up levels of atmospheric methane, but it cannot reliably isolate the hydrocarbon during the detection process. The device also picks up signals of other gases, ruining the integrity of methane data.
Mumma described the problem with a simple analogy. Consider four fingers of the human hand, stretched out. The methane lines run along the fingers, which the sensor detects. The sensor then detects the space between the fingers. With these two numbers, IRSO thought it could deduce reliable methane measures.
"The problem, of course, is that when you have other spectral lines … like carbon dioxide lines which vary widely with temperature in terms of their intensity, then those two numbers … don't represent methane alone. The net effect is that there is no way that one can back out those two signals in order to retrieve a methane signal," he told Seeker.
When asked about the flaw, ISRO spokesman Deviprasad Karnik dodged the question. India’s Mars Orbiter Mission reached the planet two years ago but has yet to publish methane data.
