A team of astronomers have recently discovered an asteroid that has been following Earth around in the same motion about the Sun for at least 250,000 years.

The team, from Armagh Observatory in Northern Ireland, feel it might be related to the origin of our planet.

The scientists Apostolos Tolis Christou and David Asher first saw the asteroid about  two months after the WISE infrared survey satellite spotted it. It is the exact same distance from the Sun as the Earth, with a mimicked orbit. Most asteroids that are similar have odd, oval orbits, but this one is circular so it remains the same close distance to our planet.

To solve stability issues of the orbit and how long the asteroid has been there was difficult. Normally they would have to track it for years. In this case, they created virtual copies of the asteroid, and simulated their evolution for two million years past and in the future.

They found the copies remained in the same location to the Earth, mimicking its movement.

There are currently three others that are similar and known to exist, however, they move onto other orbits after a few thousand years. This one, too, is also the largest.

Christou and Asher are seeking to find out its evolution, although they believe it might be from the Main Belt between Mars and Jupiter or a piece of the Moon that left the Earth-Moon system and moved into an independent orbit around the Sun. It could also have leaked from a population of objects near the triangular equilibrium points 60 degrees ahead of and behind Earth in its orbit.

They are also researching its physical properties from the ground. Colour, for example, measures its reflectivity across the electromagnetic spectrum, which can give some indication on its origin.

The study was published in the journal Monthly Notices of the Royal Astronomical Society.

For more information visit Royal Astronomical Society (RAS).

Similar Posts:

Share