The European Space Agency’s (ESA) ExoMars Trace Gas Orbiter has finally begun its scientific mission around the Red Planet and scientists hope to use the data it collects to answer a particularly intriguing question: is there life on Mars?
Just over a month ago, the spacecraft concluded a year's worth of “aerobraking” using the Martian atmosphere to go from a 98,000-kilometer-high (60,890-mile-high) elliptical orbit to an almost circular one, 400 kilometers (250 miles) above the surface. The Trace Gas Orbiter has already sent us some incredible images of the Red Planet but now its true mission begins. It will try to sniff out life.
"This is a major milestone for our ExoMars programme, and a fantastic achievement for Europe," Pia Mitschdoerfer, Trace Gas Orbiter mission manager, said in a statement. "We have reached this orbit for the first time through aerobraking and with the heaviest orbiter ever sent to the Red Planet, ready to start searching for signs of life from orbit."
The probe's goal is to identify the Red Planet's “trace gases”, all the substances that make up less than 1 percent of the Martian atmosphere. But the scientists also hope to find gases that are produced through biological activity. Methane is one gas to look out for.
On Earth, methane is a byproduct of life and the great majority of it comes from biological processes. Volcanic and hydrothermal activities can also release methane. Either scenario is really exciting. On Mars, methane has a lifetime of about 400 years, which is quite short. If the Trace Gas Orbiter detects methane, it means that Mars has stuff going on below its surface.
"We will start our science mission in just a couple of weeks and are extremely excited about what the first measurements will reveal," Håkan Svedhem, the orbiter's project scientist, stated earlier this month. "We have the sensitivity to detect rare gases in minute proportions, with the potential to discover if Mars is still active today – biologically or geologically speaking."
Traces of methane have been detected by ESA’s Mars Express mission and more recently by NASA’s Curiosity rover, but the Trace Gas Orbiter will provide measurements a thousand times more accurate and could also help us distinguish between the potential sources of methane.
As early as a few months from now, we might finally have an answer to the Bowie-esque question and learn a lot more about our place in the universe.