Mike Brown A planetary astronomer: Asteroid is a Dance Partner for Earth

A team of Canadian scientists have discovered a "Trojan" asteroid that is caught in a synchronized orbit with the Earth. Many such asteroids have been found near other planets.

We get an explanation from Mike Brown,who is a planetary astronomer at the California Institute of Technology  told, It's only been watched for a little bit of time right now and it's on the very intricate dance in front of the Earth. It's not between the Earth and the sun. It's actually in the same orbit as the Earth, so it goes around the sun in one year, just like the Earth goes around the sun in one year. And, on average, it's about the same distance from the sun as the Earth is.

 It's close.on average, we overtake its position about every two months. So, in two months from now, we are going to be where it is right now.

The reason it takes so long to see, the reason it has been so long to find one of these things is because, most of the time when we're looking for asteroids or anything else in the solar system, we look out beyond the Earth. We look into the night sky. To find these things that are actually in the same orbit of the Earth, you really have to look in the very early morning or the very, very early evening, as the sky is really quite bright, so no one has found these things up until now.

It stays 60 degrees in front of the Earth as it goes. But it doesn't really stay in that spot. It goes ahead and then comes back behind and then keeps circling around.

And so it's in this position where it's a stable orbit, where it can stay in that place for a long time. But because of the Earth and because of the sun, it keeps on moving it around.

He told, I think they're interesting much more because of their scientific interest. They really are these windows into the very earliest solar system. They are materials that are left over from when the sun and the Earth and the planets formed. And they have been sitting around in space for that past 4.5 billion years.

And if we can find them and study them and figure out where they are and where they have come from, we have learned an awful lot about our very own origins.

This is actually a really good one to have found, because even though it has the same orbit as us, it can never come any closer to us than a certain distance, because it's stuck by the Earth, never or maybe in 20,000 years. We don't know what is going to happen then.

But, for the foreseeable future, it's going to be staying there. We are going to be watching it. It's going to be a really fun dance to watch.