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ATLANTA — Mars is spinning faster than it used to, according to data collected on Mars by NASA’s lander InSight.
The now retired Insight was equipped with an array of instruments, including antennas and a radio transponder called RISE (Rotating and Internal Structural Experiment). These instruments were used to track the rotation of Mars during the first 900 days of the Mars mission.
Astronomers have confirmed that Mars’ rotation is increasing by about 4 milliseconds per year². That means her day length on Mars is being shortened by a fraction of a millisecond per year. A day on Mars lasts about 40 minutes longer than a day on Earth.
The increase in acceleration seems incredibly small, but researchers aren’t sure why. However, they suggest that it could be due to the accumulation of ice at the poles of Mars, or the uplift of land masses after being covered by ice. This change in planetary mass can accelerate the rotation of the planet.
The findings are based on analysis of shared InSight data before the mission was decommissioned due to a power outage. June study published in Nature.
The InSight mission, the first mission to explore the interior of Mars, was originally scheduled to last about two years after landing in November 2018, but NASA has extended the mission for another two years.
The InSight mission continued to collect data on Mars until the end. Silent December 2022 Because the dust blocked the sunlight on the solar panel.
Scientists used a deep space network to send a signal to InSight’s RISE and bounce the signal back to Earth. These relayed signals helped researchers track small frequency changes caused by Doppler shifts that change the pitch of the siren with distance. Changes in frequency are correlated with the rotation of the planet.
“What we are looking for is just a few tens of centimeters of change on Mars over a one-year period,” said study lead author Sebastien Le Mestre, RISE principal investigator at the Royal Observatory of Belgium, in a statement. . “It takes a very long time and a lot of data to accumulate before we can see these fluctuations.”
Measuring the Mars Wobble
Previous research, made possible by the mission’s unique detection of Mars’ interior, has confirmed that Mars has a core of molten metal. The researchers then used RISE to measure the wobble of Mars as its core wobbles within its interior.
Tracking Mars’ wobble, or nutation, has allowed the team to measure the size of its core.
RISE data suggests a core radius of about 1,140 miles.
This new number was compared to the previous core radius estimate. Track and collect seismic waves as they traveled through the interior of Mars. Combining these measurements, the researchers estimate the radius of Mars’ core to be between 1,112 and 1,150 miles.
Although InSight is no longer operational, the gold mine of data collected over four years on the surface of Mars has changed the way scientists understand the Red Planet. The mission is the first to reveal some of the secrets of Mars’ interior, and scientists will be analyzing the data for decades to come.
“It’s really cool to get these latest measurements, and they’re accurate,” said Bruce Banert, who was InSight’s principal scientist until his retirement on August 1. He worked at NASA’s Jet Propulsion Laboratory in Pasadena, California for 46 years.
“I have long been involved in efforts to launch geophysical observatories like InSight to Mars, but results like this are well worth decades of effort.”