Scientists Discover Mars’ Spin is Speeding Up
In a surprising discovery, scientists studying data gathered by NASA’s InSight lander have found that the spin of Mars is accelerating. The InSight lander, which fell silent in December due to accumulated dust on its solar panels, provided scientists with four years’ worth of data to analyze.
Most of the information collected about Mars came from InSight’s sensitive seismometer, which measured vibrations from marsquakes and meteor impacts. However, additional findings were recently published in the journal Nature, revealing insights gained from analyzing radio transmissions between Earth and InSight on Mars.
The Doppler effect, a phenomenon caused by the relative motion of two objects, was used to measure changes in the frequencies of radio waves. This allowed scientists to track shifts in Mars’ rotation by analyzing variations in the wavelengths and frequencies of the radio signals.
After accounting for the distortions caused by Earth’s atmosphere and the solar wind, scientists discovered leftover frequency variations that could be attributed to Mars’ wobbling rotation. By precisely measuring these wobbles, researchers were able to estimate the size and composition of Mars’ molten core.
The measurements indicated that the molten core of Mars is approximately 2,280 miles wide, matching seismic observations of the planet. Surprisingly, no solid inner core, similar to Earth’s, was detected. The core was found to consist mainly of molten iron but also contained lighter elements such as sulfur, oxygen, and carbon.
Researchers also observed the anticipated fluctuations in Mars’ rotation, which were influenced by the shifting distribution of frozen carbon dioxide in the ice caps throughout the seasons.
However, the most unexpected finding was a slight speeding up of Mars’ spin since measurements taken during NASA’s Viking missions in the 1970s. This acceleration has resulted in a shortening of a Martian day by about 1.5 millionths of a second per Martian year.
Scientists are currently unsure of the cause behind this increase in speed. While the moon Phobos falling closer to Mars does contribute to the acceleration, it does not fully explain the observed phenomenon. One proposed explanation is the long-term accumulation of ice at the poles, causing a change in the planet’s shape and thus speeding up its rotation. Another possibility is the melting of glaciers in the polar regions, resulting in the rebounding of the planetary crust.
Although less probable, asteroid impacts could also play a role in Mars’ increased spin. Further research and analysis will be conducted to determine the exact cause of this unexpected phenomenon.
While Earth experiences a lengthening of the day due to the moon’s gradual movement away from the planet, Mars seems to be defying this trend. Understanding the changes in Mars’ rotation will provide valuable insights into the planet’s internal structure and composition, shedding light on its formation and evolution over time.