The first color image to come from a camera aboard the ExoMars Trace Gas Orbiter in its Mars-mapping orbit shows the ice-coated rim of Korolev Crater in sharply shadowed detail.

“We were really pleased to see how good this picture was, given the lighting conditions,” Antoine Pommerol, a member of the science team for the Color and Stereo Surface Imaging System, said today in a news release. “It shows that CaSSIS can make a major contribution to studies of the carbon dioxide and water cycles on Mars.”

The ExoMars Trace Gas Orbiter, a mission jointly supported by the European and Russian space agencies, is built to measure the composition of Mars’ thin atmosphere with unprecedented accuracy. Its top task is to look for methane and other trace gases that could hint at biological or geological activity.

The car-sized probe was launched in 2016, and after a series of aerobraking maneuvers, it reached its final 250-mile-high orbit around Mars this month. Its spectrometers began “sniffing” atmospheric molecules just last weekend.

CaSSIS has been going through a test phase for more than a month, in preparation for a primary science mission that’s due to begin on Saturday. (The camera sent back images of Mars and a color view of the Martian moon Phobos during earlier orbital tests going back to 2016.)

“We have had a couple of minor software issues in the initial test phase,” the camera’s principal investigator, Nicolas Thomas of the University of Bern in Switzerland, said in a news release. “But the instrument is actually in good health and ready to work.”

Three CaSSIS images in different wavelengths were captured on April 15 and combined to produce the picture of Korolev Crater, named after pioneering Soviet rocket engineer Sergei Korolev.

CaSSIS and the sniffing spectrometers are part of an array of scientific instruments that will track seasonal changes in the atmosphere’s composition and temperature, and link those changes to features on the Martian surface. For example, CaSSIS could conceivably spot volcanoes or ice deposits that are associated with trace methane emissions.

“Our aim is to fully automate the image production process,” Thomas said. “Once we achieve this, we can distribute the data to the community quickly for analysis.”

The Trace Gas Orbiter is part of a European-led scientific campaign that also includes a Mars rover and a surface science platform, due for launch in 2020. In addition to its scientific duties, the orbiter will serve as a communications relay satellite for those robotic probes.

That relay capability was successfully tested this week with NASA’s Curiosity rover, ESA said.