OPINION: By Jupiter: the gas giant’s Trojans were captured, not pre-formed

An artist's concept of the first known Earth Trojan asteroid and its extreme orbit, shown in green. Earth's orbit around the sun is indicated by blue dots. Image: Paul Wiegert/University of Western Ontario You’ll remember that, about a year ago, Canadian astronomers announced the discovery of a small asteroid sharing the Earth’s orbit. The asteroid in question, 2010 TK7, is a “planetary Trojan” – an object sharing an orbit with a planet. While Earth only has one such companion (that we know of), the giant planets Jupiter and Neptune are accompanied by vast swarms of these objects. Both likely host at least a million Trojan asteroids larger than 1km in diameter, trapped in swarms that both lead and trail the host planet in its orbit. Just recently my fellow researchers and I discovered that a “Jovian” Trojan (sharing an orbit with Jupiter) discovered in 1930, (1173) Anchises, is actually unstable – that is, it will...

Read the whole article on Science Alert

More from Science Alert

Related