After a year of “aerobraking” that ended in February, The ESA-Roscosmos joint ventured rover-Trace Gas Orbiter (TGO) has finally reached its target orbit around Mars. In about two weeks’ time, the European Space Agency and Roscosmos orbiter will commence its operation of scanning the Martian atmosphere in search of traces gases, including those which could hint the possible life on the red planet.

In the second week of April, the spacecraft transitioned from a highly elliptical orbit to near-circular one which positions it 400 km (250 miles) above the surface of the Mars. ExoMars now orbits the planet once every two hours which enables it to proceed with its scientific objectives. After making some final calibrations and installation of new software, the probe will point its various gas-detecting instruments at the Martian atmosphere.

The atmosphere present in Mars is extremely thin- about 100 times thinner than Earth’s. It mostly consists of carbon dioxide (95 percent), followed by nitrogen (2.7 percent), and oxygen (1.6 percent). It also includes trace gases accounting for less than 1 percent of the atmospheric gases present in the planet. The scientists intend to search for the chemical gas Methane. Methane is released from the volcanoes, hydrothermal vents, and natural hydrocarbon gas reservoirs. It is also produced as a byproduct of biological organisms. The chemical lasts for about 400 years only. It gets broken down by the ultraviolet rays of the Sun and is dispersed by high atmospheric winds. If ExoMars can detect methane’s presence from the Mars’ atmosphere, it could mean that the planet is still very geologically active. It could also indicate the planet’s ability to support biological life.

Previously, scans to detect the gas were also attempted by ESA’s Mars Express and NASA’s Curiosity Rover. Both the missions hinted the presence of methane, but the results were found unconvincing. ExoMars is equipped with three times more powerful sensors in an attempt to obtain convincing results. With the help of various sensors and cameras, it will peek into the atmosphere, scan the Martian surface, and even detect what lies underneath.

The spacecraft launched in March 2016 as a part of the joint mission called ExoMars of ESA and Russian space agency Roscosmos is due to land on the planet in 2020 and lead the next phase of the mission. The rover will draw soil samples from beneath the surface and look for evidence of present or past life.