Earth trojan

This is a trojan asteroid which shares an orbit around the Sun with the Earth.  The story begins, however, with Jupiter which was discovered to have a large number of these asteroids in its orbit. The latest estimate is that there are about 1 million Jupiter trojans over 1km in diameter. They form swarms or families. The naming policy is to call them after the heroes of the Trojan War. The asteroids in the leading orbit are given the names of Greek heroes in the war and those trailing are given the names of Trojan heroes. And so collectively they are known as the Trojan asteroids.

But then similar asteroids were discovered in orbit with other planets. Mars, Venus, Uranus and Neptune all have them. In 2010 Earth was discovered to have one. Early this year scientists confirmed that we have another Earth trojan which has the name 2010 XL5. This one is larger than the first and is expected to stay in Earth’s orbit for about 4,000 years before deviating away. Both Earth trojans are ahead of us in the orbit.