A 3D illustration showing NASA’s Opportunity rover in Perseverance Valley on Mars. Seán Doran/Flickr (CC BY-NC-ND 2.0); Business Insider

A satellite orbiting Mars has taken a remarkable yet potentially somber photo of NASA’s longest-lived robot on the red planet.

That robot is the Mars Opportunity rover, which is about the size of a golf cart, landed in January 2004, and was supposed to last 90 days. However, Opportunity has explored Mars for more than 15 years and trekked more than 28 miles across the planet using solar energy.

Its days may be numbered, though.

When a global dust storm began to envelope Mars about 100 days ago, Opportunity stopped getting enough sunlight to its solar panels. This triggered it to go to sleep on June 10 and conserve battery power, which the rover needs to run heaters that protect its circuits from blistering Martian cold.

“The rover’s team at NASA’s Jet Propulsion Laboratory in Pasadena, California, hasn’t heard from the rover since,” Andrew Good, a representative for the lab, wrote in a press release.

Though a new satellite image gives mission controllers hope that Opportunity will wake up, the mission may be nearing its end.