There’s a new step in our journey to learn more about the planet Mars, beyond just the fact that it turns, but that its poles constantly move as it rotates.
The finding comes from a study by Geophysical Research Letter, which also outlines that it is the first planet discovered to have a balance beyond Earth.
It’s known as a ‘Chandler wobble’, in honour of Carlo Chandler who discovered the movement more than a century ago.
An effect of the wobble is that the rotation is not a perfect sphere, more like an ellipsis, which loses speed as it rotates.
In this case, the poles become displaced by 10 centimetres, far less than the nine metres which the Earth shifts with each rotation. The process takes 207 days, compared to 433 days on earth.
“In general, the signal of Chandler’s wobble is very small, it would need many years and high-quality data to detect it,” said Alex Kanopliv, aerospace engineer at NASA’s Jet Propulsion Lab.
This research was possible thanks to the Mars Odyssey and Mars Reconnaissance Orbiter, which have been working for 18 years to collect data.