ExoMars: Revealing Mars's ancient past

ExoMars Trace Gas Orbiter


Mission status: Active

ExoMars rover

Launch window: to
Mission status: Preparing for launch

The ESA's ExoMars program is a two-part Mars exploration mission carried out in collaboration with Roscosmos.


The main scientific objective of the ExoMars program is to establish whether life ever existed on Mars. However, ExoMars and also aim to demonstrate key abilities that will help pave the way for future Mars missions:

Landing on Mars is notoriously difficult. In fact, only about half of all attempts to land on Mars have been successful. In , the Schiaparelli module crashed on the Martian surface. Data from the anomaly was investigated, and lessons learned will be applied to future missions.

The thinness of the Martian atmosphere means that an entry, descent, and landing sequence must happen quickly and with extreme precision. When the ExoMars descent module enters the Martian atmosphere, it will be travelling at about 20,000 km/h. Its thermal shield and parachute system will slow the vehicle down, and rocket engines will fire to land the rover gently on the surface.

The ExoMars mission will land in the Oxia Planum region on Mars, some of which is seen in this image captured by the Mars Reconnaissance Orbiter. The clay-rich area was chosen mainly because of its scientific value: researchers believe that volcanic activity covered early water deposits, a process that may have preserved fragments of ancient life. (Credit: NASA/JPL/University of Arizona)

Canada's role in the mission

Thanks to a cooperation agreement between Canada and ESA, Canadian companies were able to bid on contracts for the ExoMars missions:

ExoMars Trace Gas Orbiter

The ExoMars TGO searches for evidence of methane and other gases that could be signatures of active biological or geological processes on Mars. The TGO will also serve as a communications relay for the rover and science landing platform that will be launched in . (Credit: ESA–D. Ducros)

The Canadian Space Agency is also funding two Canadian scientists taking part in the Orbiter mission:

Together, the ExoMars  and missions will give scientists a better understanding of the Martian atmosphere, provide clues as to whether life ever existed on Mars, and help test technologies for a future possible Mars sample-return mission.

Why study methane in Mars's atmosphere?

Measuring the makeup of the Martian atmosphere is a critical part of the search for life on the red planet. Methane gas can be formed on Earth through geological processes (like volcanoes) or biological ones, as a by-product of life.

Within Mars's thin atmosphere, methane breaks down easily due to ultraviolet radiation from the Sun. Thanks to spacecraft like the TGO, researchers are tracking levels of methane and other trace gases, and taking a closer look at the cycle of formation and breakdown of methane in the Martian atmosphere. These careful measurements will help pinpoint its source – ultimately shedding light on the possibility of recent, microscopic life on Mars.

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