Astronomers from U.S. space agency Nasa and the University of Leicester in the UK have discovered a giant black hole that is vaporising and devouring asteroids. This black hole is located at the centre of the Milky Way galaxy.

Astronomers have detected X-ray flares from Sagittarius A - a super massive black hole - at least once in a day. The brightness of the flares keeps varying from time to time and the flares last a few hours. These were detected from NASA's Chandra X-ray Observatory.

Sagittarius A is surrounded by a huge thick cloud that contains trillions of asteroids and comets. Asteroids passing within a 100 million miles of the black hole - roughly the distance between the Earth and the sun - seem to be torn into pieces by the tidal forces from the black hole. These fragments are then vaporized by friction as they pass through the hot, thin gas flowing onto Sagittarius A. The process is similar to a meteor heating up and glowing as it falls through the Earth's atmosphere. A flare is produced when it enters the black hole and the remains of the asteroid are swallowed eventually by the black hole.

According to the astronomers, a huge asteroid that is located near a black hole can generate the huge flares that can easily be observed through Chandra. However, the smaller asteroids could be difficult to spot because the flares they generate would be fainter.

Astronomers are also planning, sometime in the future, to learn more about the frequency and brightness of flares. The hope is that this work will help them understand the formation of asteroids and planets in the harsh environment of Sagittarius A.

"An asteroid's orbit can change if it ventures too close to a star or planet near Sagittarius A," said Sergei Nayakshin from the University of Leicester, "If it's thrown toward the black hole, it's doomed."