Trojan Ahoy! Uranus Has a Plus-One
01/09/2013 15:49
Earth has one. Jupiter has more than 5,000. And now astronomers know that Uranus, despite its odd, sideways orbit around the sun, has a tag-along companion too.
This type of object, known as a “Trojan,” compatibly shares a planet’s path around the sun, thanks to a neat trick of orbital...