What is this “semi-moon” that has followed the Earth for thousands of years?

“2023 FW13” is the name of the “semi-“moon It was discovered on March 28 from the PanSTARRS observatory in Hawaii (United State). according to Futura Sciences And TF1 NewsIt is actually a small asteroid about twenty meters in diameter Land during its journey around the sun.

According to the Astronomy scientists, This celestial body is currently more than 10 million kilometers away from the blue planet, or 25 times the distance separating the Earth from the real moon. Astronomer at the University of Geneva Observatory and science journalist for our colleagues from Futura, Adrien Coffinet detailed the discovery.

More than 2000 years of history

According to him, theasteroid It was orbiting the Sun when it crossed paths with the Earth. This encounter disrupted its orbit slightly. “If we look from the Earth, we already have the impression that it revolves around us, but it is not the Earth’s gravity that determines its orbit,” Jeremy Vaupillon, assistant astronomer at the Paris Observatory, told our colleagues from Figaro Sciences. In other words, the asteroid is orbiting sun while remaining close to Earth, hence the name “quasi-satellite” used by Adrien Coffinet.

With the help of amateur astronomer Tony Dunn, the latter entered the orbital parameters of “2023 FW13” into a simulator. The two researchers then found that the asteroid had been in this vicinity for more than two thousand years.

A “starting point” for Mars?

“It appears to be the longest planet-like satellite known to date,” Adrian Covenet told Sky and Telescope magazine. Usually, these objects follow the Earth for a few centuries at most. According to the French astronomer, “2023 FW13” should continue to defy the rule by staying close to our planet until the year 3700 AD.

Planetary scientist Richard Penzel, an instructor at the Massachusetts Institute of Technology (MIT), considers that these “quasi-satellites” could serve as a “stepping stone” in the perspective of a journey to Mars. He believes spacecraft can reach these slow-moving asteroids in just a few months.

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