Bermuda is in line to be one of the best places on Earth to observe a once-in-a-millennium extreme close encounter with an asteroid hurtling through space.

A space rock with a diameter the length of a Panamax cruise ship will skim past the Earth as it is pulled off course by our planet's gravity.

Latest calculations from NASA, to be published in January, reveal the asteroid will shoot past at a distance of just 18,300 miles away — and its closest approach will be directly above the mid-Atlantic.

Such extreme close encounters are thought to happen only once every 800 to 1,000 years. Although the event is still just over 21 years away, scientists have worked out the asteroid will come so close it will duck under a congested ring of man-made satellites that circle the Earth and beam TV, telephone and other communications around the world.

For those watching the spectacle, the asteroid will appear as a particularly bright starlike object moving fairly rapidly across the sky.

The asteroid is called '99942 Apophis', named after an Egyptian demon, and has a diameter of 320 metres.

For the superstitious there is the added worry that the close encounter will occur on Friday the 13th in April 2029. And as if that is not enough, scientists are seeking more data to figure out whether the asteroid might collide with the Earth exactly seven years later, on Easter Sunday 2036, which is again the 13th.

The reason for the 2036 concern is the uncertainty that arises from the 'blurring' of the asteroid's predicted path when it is bent off course during its rendezvous with our planet in 2029.

Although highly unlikely, a tiny keyhole of probability exists that the asteroid, which orbits the sun, could go on to hit the Earth when it returns in 2036.

Important observations to confirm the asteroid's 2036 trajectory are due to be made once it has cleared the obstruction of the sun sometime between 2011 and 2013.

Paul Chodas, of NASA's Near Earth Object Programme, estimates that if the space rock hit it would devastate an area of land the size of Texas or, if it landed in an ocean cause widespread tsunamis.

Jon Giorgini, of the Jet Propulsion Laboratory, a NASA laboratory based in California, is lead author of the new paper on Apophis, which is published in the January issue of the scientific journal Icarus.

He concludes: "The future for Apophis on Friday, April 13 of 2029 includes an approach to Earth no closer than 29,470 km (18,300 miles) over the mid-Atlantic, appearing to the naked eye as a moderately bright point of light moving rapidly across the sky.

"Depending on its mechanical nature, it could experience shape or spin-state alteration due to tidal forces caused by Earth's gravity field.

"This is within the distance of Earth's geosynchronous satellites. However, it does not threaten the satellites in that heavily populated region.

"Using criteria developed in this research, new measurements possible in 2013 (if not 2011) will likely confirm that in 2036 Apophis will quietly pass more than 49 million km (30.5 million miles) from Earth on Easter Sunday of that year (April 13).