ExoMars is a European spacecraft that is currently orbiting Mars. It is reportedly ready to begin its search regarding signs indicating traces of life on Mars.
The ExoMars Trace Gas Orbiter (TGO) will start this mission in the following week or two. It has successfully completed a year-long aerobraking manoeuvre that was critical before beginning this mission.
Reports say that the primary objective of this mission is to “smell” the atmosphere in Mars, basically searching for the evidential presence of methane. Methane detection can indicate active life form that might be present on or even below the surface of the red planet.
Pia Mitschdoefer, the European Space Agency (Esa) mission manager calls this as a major milestone in their ExoMars programme and also ground breaking achievement for Europe as a whole. This is because the Martian orbit has been reached through aerobraking for the first time ever and also with one of the heaviest orbiter.
TCO is specially designed to be able to sample even minute quantities of trace gases that serve to make up less than 1% of the atmosphere of Mars and then analyze them. It is a scientifically known fact that methane in atmosphere would be broken down by sunlight and eventually disappear if it wasn`t replenished on a continuous basis. Hence, detection of methane even in traces in Martian atmosphere would prove a vital point about signs of life in the planet.
On Earth, methane gets produced by microbial activity. The gas is also released by certain geological activities like volcanic eruptions or from any naturally occurring reservoirs of hydrocarbons. However, TGO would be able to detect the difference between biological and geological origin of methane gas.