The silent 'companion' of the earth

Astronomers have discovered a large meteorite that moves on Earth for at least 250 thousand years.

Daily Science said the WISE space telescope - launched by the US in 2009 and capable of infrared photography - found a meteorite flying near the earth last year. They named it 2010 SO16 . Its diameter is about 200 to 400 m. So astronomers can observe it at night with medium-sized telescopes.

Apostolos Christou and David Asher, two scientists of Armagh Observatory in Northern Ireland, are very interested in this asteroid because the average distance between it and the sun is exactly the average distance from the sun to the earth.

' But what impresses me is that its trajectory is very similar to Earth ,' said Dr. Christou.

Most meteorites near the earth have an egg-shaped orbit. But 2010 SO16 moves in a nearly circular orbit, so it cannot reach any planet in the Solar System, except for the planet.

Meteorite 2010 SO16. Photo: scienceray.com.

After a period of research by model, Christou and Asher concluded that 2010 SO16 has been flying around the earth around the sun for at least 250 thousand years.

" It will still appear in the night sky for many years, " Asher said.

Although also flying around the sun, 2010 SO16 always kept a great distance from the earth. According to the two doctors, throughout the hundreds of thousands of years through its distance to the Earth, it is always 50 times the distance from the moon to the earth.

The two researchers put forward many theories about the origin of meteorites. For example, it may be a normal meteorite in the Meteorite Belt between Mars and Jupiter. Another theory is that 2010 SO16 is a fragment of the moon. After escaping the attraction of both the moon and the globe, the debris flew around the sun in an independent orbit.