A DUMBELL SHAPED asteroid measuring four to five miles across will pass close by the Earth today.
Toutatis, considered one of the more unusual objects in the solar system because of its shape and elongated orbit, will come within just three million miles. Although approximately 12 times further away than the Moon - relatively near in astronomical terms - it will be observable low in the southern sky.
Scientists fear that a major collision could devastate life on the planet causing widespread extinction similar to those which wiped out the dinosaurs.
"Toutatis, if it landed on Earth, would have the force of exploding the entire world's nuclear arsenal," Dr Roderick Willstrop of Cambridge University's Institute of Astronomy warned.
"But it cannot have a collision in its present orbit. All orbits of the minor planets, however, are being affected by the gravitational pull of major planets and we do not know exactly what effect this could have in the future," he added.
"There are no asteroids known currently on a collision course with Earth although there are many which have not been discovered yet."
Toutatis, discovered in the early 1980s and numbered 4179, has its unusual shape because of the relatively low gravitational force at work on it, which makes larger celestial bodies spherical.
Leading scientists recently warned world governments that cosmic impact presents one of the major dangers to life. Some believe the chance of dying because of one is greater than being killed in an air crash. Military experts are even suggesting they get involved in defending the Earth from collision.
The theory that dinosaurs were killed by asteroids, resulting in massive climate change and so called nuclear winter where debris and dust thrown up from the explosion blocks out sunlight, has grown in recent years. Geological evidence also supports the notion that there may have been a major impact from space 65 million years ago - the same time that dinosaurs became extinct.