Mars is spinning faster than before. Such data was received by the NASA InSight lander. CNN writes about this.
The retired InSight was armed with a set of tools, including antennas and a radio transponder called RISE. The instruments were used to track the rotation of Mars during its first 900 days on the planet.
Astronomers have determined that the planet's rotation is increasing by about 4 milliseconds of arc per year², or shortening the length of a Martian day by a fraction of a millisecond per year. A Martian day is about 40 minutes longer than a day on Earth.
The increased acceleration seems incredibly small, and researchers aren't quite sure what causes it. However, they suggest that this may be due to the accumulation of ice at the Martian poles or the rise of the land after it was covered in ice. When the planet's mass shifts in this way, it can cause the planet's rotation to accelerate.
The findings, based on analysis of InSight data transmitted before the mission ran out of power and was closed, were presented in a June study published in the journal Nature .
The InSight mission, the first to explore the interior of Mars, was originally supposed to last about two years after it landed in November 2018. But the agency extended the mission for another two years.
The InSight mission continued to collect data on Mars until the very end, until dust blocked the solar panels from sunlight.