A bus-sized asteroid will pass by Earth this Friday, 27 January 2012, coming as close as one-fifth the distance to the moon.

NASA scientists say the 37 foot-wide space rock poses no danger to Earth.

The newly discovered asteroid 2012 BX34, is small by asteroid standards, and will pass within 59,044 kilometres of Earth at around 1530 GMT Friday.

Nasa used Twitter to announce the asteroid's arrival in our galactic neighbourhood via their @AsteroidWatch account.

The space agency said the asteroid could not harm our home planet, tweeting: "Asteroid 2012 BX34 is small, ~11 meters/37 ft diameter. It wouldn't get through our atmosphere intact even if it dared to try."

The asteroid was spotted from Chelmsford, UK, last night by British Astronomical Association member Nick James.

A large number of asteroids will pass close to earth this year, including four more in February. For the full list, see Nasa's Near Earth Object Program.

Image shows asteroid Lutetia.