Mercury is spinning a whopping 9 seconds faster than originally thought
Scientists have already been aware that Mercury spins three times on its axis for every two revolutions around the sun. Originally, experts thought that the Sun was what influenced the planet’s rotation. It has recently come up in studies that Jupiter is possibly also influencing Mercury’s orbit and spin.
This has made them see that Mercury is more complex than originally believed: A planetary scientist with the University of California, Los Angeles, Jean-Luc Margot, a co-author of this new study, has found that Mercury is spinning on its axis about 9 seconds faster than scientists had originally thought, and it also does not spin smoothly.
How Information on Mercury Spins was Uncovered
A spacecraft called MESSENGER was sent up to Mercury to study the planet back in April 2011. Originally designed for a one year mission, the spacecraft lasted for 3,308 orbits around the planet, and then actually crashed into Mercury in April 2015. This has created the opportunity for scientists to study new data that includes the internal structure as well as how Mercury operates. They knew that Mercury had an 88-day rotation cycle that fluctuates in the amount of time based on where it is around the sun, but after the MESSENGER spacecraft sent back the acquired data, they realized that Jupiter’s gravitational pull is what could be creating a whole different cycle with Mercury. This pull is the cause of the Mercury spins turing out to be occur 9 seconds faster than originally thought.
Jupiter tugs on Mercury
Scientists have surmised that Jupiter has created a libration, or oscillating motion, within Mercury, that occurs every 12 years, to match Jupiter’s rotation around the sun, which also occurs every 12 years. They believe this could account for the constant slowing down and speeding up motions that Mercury has displayed.
Inside Mercury
Because of the way the planet oscillates, the researchers believe that the planet is not completely solid, but actually has a molten outer core. If this is the case, it means that the inner layers are not completely locked together, which will cause bigger oscillations between the outer core and the sun. This would especially happen when Mars is rotating closer to the sun.
Currently the data is still being analyzed and there is still a lot more to learn about the planet closest to the Sun.
