May be the last image I can send: NASA's Insight rover says it is signing off from Mars

NASA’s InSight spacecraft, the first robotic lander designed to study the deep interior of a distant world, which touched down safely on the surface of Mars four years with instruments to detect planetary seismic rumblings has put out a post in its official Twiiter handle which is signalling the end of the rover in Mars.

“My power’s really low, so this may be the last image I can send. Don’t worry about me though: my time here has been both productive and serene. If I can keep talking to my mission team, I will – but I’ll be signing off here soon. Thanks for staying with me”, it posted.

NASA's InSight rover made the first-ever detection of quakes on the Red Planet. Its onboard seismometer has measured over 1,300 seismic events, and over 50 of them had clear enough signals for the team to derive information about their location on Mars.

The largest cluster of high-quality events came from Cerberus Fossae, a region that shows evidence of geologically recent volcanism – within the last two million years. The instrument picked up all six of the largest events of the mission since the middle of 2021. The most recent one, in May 2022, had an estimated magnitude of 5, with vibrations reverberating through the planet for at least six hours.

InSight gathered new information about Mars' three major layers – crust, mantle, and core. Scientists found that the crust beneath InSight is somewhat thinner than expected – about 15 to 25 miles (25 to 40 kilometers) thick, comprising three internal layers. The crust's top layer is about 6.2 miles (10 kilometers) thick, and less dense than the lower crust. Mars' core is molten and considerably larger than expected, about 1,120 miles (about 1,800 kilometers) in radius. The lower density means that there are lighter elements mixed with the molten iron, lowering its melting point. This helps explain how Mars’ core can still be molten despite having cooled considerably since its formation.

InSight also investigated the upper mantle using seismic waves traveling through depths of about 500 miles (800 kilometers) before returning to the surface. The strong, cold outer shell, the lithosphere, is about 310 miles (500 kilometers) thick, above a relatively cool mantle, compared to Earth's mantle.

Determining the composition and structure of the layers, and how quickly heat seeps out of them, helps us better understand the geologic history of Mars’ surface, and in particular its ability over time to support life.

InSight was the eighth spacecraft to have landed successfully on Mars, all of them operated by NASA.

The three-legged lander streaked into the thin Martian atmosphere at 12,300 miles (19,795 km) per hour and plunged 77 miles to the surface within seven minutes, slowed to a gentle touchdown by atmospheric friction, a giant parachute and retro rockets.

The stationary probe was programmed to pause for 16 minutes for the dust to settle, literally, around its landing site, before two disc-shaped solar panels were to be unfurled like wings to provide power to the spacecraft.

But scientists did not expect to verify successful deployment of the solar arrays for at least several hours.

The 880-pound (360 kg) InSight - its name is short for Interior Exploration Using Seismic Investigations, Geodesy and Heat Transport - marks the 21st U.S.-launched Mars mission, dating back to the Mariner fly-bys of the 1960s.