Like an ice skater tucking their arms for an elegant spin, the planet Mars appears to be rotating slightly faster with each passing year.
In a paper published June 14 in the journal Nature, astronomers used data from NASA's InSight mission to show that the Red Planet's spin is accelerating at a rate of 4 milliarcseconds — one one-thousandth of an arcsecond, a unit of angularity — per year. As a result, the length of a Martian day is getting shorter by fractions of a millisecond annually.
