'Asteroid 2005 YU55', a rock measuring 400 metres in length and 55 million tonnes in weight, will fly by at its closest distance from the Earth at around 3.25 lakh km, smaller than the Earth-Moon average distance of 3.84 lakh km.
Although classified as a potentially hazardous object, asteroid 2005 YU55 poses no threat to the Earth in at least the next 100 years according to scientists from all over the world, Director of M P Birla Planetarium D P Duari said.
"However, this will be the closest approach to date by an object discovered on December 28, 2005," he said.
Mr Duari said the asteroid, jet black in its appearance, spherical in shape and bigger than an aircraft carrier, goes around the Sun once in 1.22 years.
He said although the asteroid is in an orbit that regularly brings it to the vicinity of the Earth, the Venus and the Mars, the 2011 encounter with the Earth is the closest this space rock has come for at least the last 200 years.
The next time a known asteroid this large will come this close to the Earth will be in 2028 when it passes at a distance of 2.48 lakh km from the planet.
According to Duari, scientists are planning to have detailed observations of the approaching asteroid by using radio antennae at Goldstone and Arecibo to bounce radio waves off the space rock.
NASA scientists hope to obtain images of the asteroid.