The search for life on Mars has entered a new era with the launch of a spacecraft built to sniff out waste gases released by alien organisms.
The ExoMars Trace Gas Orbiter (TGO) blasted into an overcast sky on a Proton rocket from Baikonur cosmodrome in Kazakhstan at 09:31 GMT on Monday.
A joint mission by the European and Russian space agencies, the probe will circle the red planet and measure minute levels of atmospheric gases, among which may be the natural waste products of microbial Martians.
Mission scientists hope in particular to get to the bottom of the Martian methane mystery. The gas is produced in abundance by life on Earth, and its presence on Mars could signify alien bugs on, or under, the surface. But the gas is also released by chemical reactions in rocks, so on Mars at least, scientists cannot yet be sure of its origins.
“Maybe, maybe we can find out if there’s life extant on the red planet,” said Mark McCaughrean, senior science adviser at the European Space Agency (ESA), moments before the launch.
Scientists have detected whiffs of methane on Mars before. In 2004, ESA’s Mars Express orbiter measured levels of methane in the atmosphere at about 10 parts in a billion, suggesting there is at least some being produced on the planet. Ten years later, Nasa’s Curiosity rover recorded spikes in methane levels on the Martian surface, pointing to localised sources of the gas.
The Russian rocket carrying the TGO burned 400 tonnes of fuel and reached a speed of 6,000km per hour in the first two minutes of its journey into space. Fifteen minutes into the flight, Micha Schmidt, a spacecraft operations manager at ESA, said the launch and initial burns that put the Proton rocket on course for Mars were “reading like a picture book performance”.
Sensors on board the TGO will sniff out traces of gases in the Martian atmosphere that should help researchers work out the source of methane on the planet. Specifically, if methane is detected alongside other complex hydrocarbons, such as propane or ethane, the source is more likely to be life than lumps of rock. But if the probe detects sulphur dioxide instead of large organic compounds, the odds will favour a geological origin for the methane.
The TGO will take seven months to travel the 308m miles to Mars. Once there, the main spacecraft will release a small lander, Schiaparelli, which will test heat shields and parachutes in preparation for future landings on the planet. It will send back data for several days after touching down.
Hopes for finding life on Mars, either past or present, received a boost last September when Nasa researchers discovered flowing water on the planet in the form of damp patches that appear on crater walls in the spring and summer months and dry up later in the year. The wet regions are likely to be off limits to rovers because of the risk of contaminating the soil with bugs carried up from Earth, but the TGO will examine them in more detail with its high-resolution camera.
The TGO is the first part of the ExoMars mission and will be followed by a rover capable of drilling up to two metres beneath the surface in search of microbial life. The rover will collect samples of Martian soil from different depths, grind them up, and analyse them for telltale organic compounds.
The six-wheeled rover is expected to trundle over several kilometres of Mars during its mission. The rover is scheduled for launch in 2018, though ESA has warned the mission may be delayed by funding problems.
