Asteroid 2004 FH passes about 43,000 km (26,500 miles) above the Earth's surface on March 18, 2004. Earth's gravity bends the trajectory of the asteroid by about 15 degrees. The asteroid crosses from one side of the Moon's orbit to the other in 31 hours.

A small near-Earth asteroid (NEA), discovered Monday night by the NASA-funded LINEAR asteroid survey, will make the closest approach to Earth ever recorded. There is no danger of a collision with the Earth during this encounter.

The object, designated 2004 FH, is roughly 30 meters (100 feet) in diameter and will pass just 43,000 km (26,500 miles, or about 3.4 Earth diameters) above the Earth's surface on March 18th at 5:08 PM EST (2:08 PM PST, 22:08 UTC).

On average, objects about the size of 2004 FH pass within this distance roughly once every two years, but most of these small objects pass by undetected. This particular close approach is unusual only in the sense that scientists know about it. The fact that an object as small as asteroid 2004 FH has been discovered now is mostly a matter of perseverance by the LINEAR team, which is funded by NASA to search for larger kilometer-sized NEAs, but also routinely detect much smaller objects.

Click on image to view 2.0 MB animation Images obtained by Stefano Sposetti, Switzerland on March 18, 2004. Animation made Raoul Behrend, Geneva Observatory, Switzerland.

The orbit of asteroid 2004 FH (shown in blue) is almost entirely within the Earth orbit. The locations of the asteroid and Earth are indistinguishable at this scale.

Asteroid 2004 FH's point of closest approach with the Earth will be over the South Atlantic Ocean. Using a good pair of binoculars, the object will be bright enough to be seen during this close approach from areas of Europe, Asia and most of the Southern Hemisphere.

Scientists look forward to the flyby as it will provide them an unprecedented opportunity to study a small NEA asteroid up close.