Data from NASA’s Insight lander has shown that Mars is spinning faster, according to a new study. The mysteries surrounding Mars just added one more.
NASA’s research team used the Deep Space Network, a space communication network on Earth, to track the Insight lander rotating with Mars for four years. They sent a radio signal from Earth to InSight and measured the change caused by the Doppler effect in the signal reflected back to the spacecraft. The Doppler effect is similar to the change in pitch of a siren as an ambulance or other vehicle passes by.
Over the life of the exploration mission, the researchers performed radio-scientific analyzes of the measurements to find out how fast Mars is currently rotating.
The rotation measurements obtained are about five times more accurate than those obtained by NASA’s Viking Mars lander in the 1970s. By the time the InSight ran out of power in December 2022 and ceased operations, the researchers found that Mars’ rotation was accelerating by a few centimeters each year.
Details of the study were recently published in the scientific journal Naturepaperreported in
According to NASA, the InSight’s RISE instrument found that Mars’ rotation is accelerating by about 4 milliseconds per year. This corresponds to the length of a day on Mars being shortened by less than 1/1000th of a second per year.
What causes rotational acceleration?
According to NASA, there are three main possibilities:
– Long-term motion of Mars interior materials and deep interior
Long-term trends in atmospheric circulation caused by atmospheric torque on Mars
Long-term accumulation of ice on the polar caps or post-glacial recoil when the underlying landmass rises (moving planetary landmasses can cause rotational acceleration. NASA explains that it’s similar to an ice skater spinning with their arms outstretched, who pulls their arms closer to their body to speed up their rotation.)
