European spacecraft approaches asteroid

Scientists at the European Space Agency's Operations Centre say the deep space Rosetta satellite has stopped sending its signal.

It's an important and welcome step as the satellite begins a flyby of an asteroid millions of kilometres from Earth.

Rosetta rendezvoused just after 2:45 p.m. ET today with the Steins asteroid — also known as Asteroid 2867 — which currently lies in the asteroid belt between the orbits of Mars and Jupiter.

ESA expects the signal to resume later, a sign that the flyby of the irregularly shaped asteroid was successful. The data and pictures taken by the satellite will be sent to the European Space Agency's control room and laboratories in Darmstadt, Germany.

The craft, launched in March 2005, is some 400 million kilometres from Earth and will pass within 800 km from the asteroid itself.

"Once we learn more about asteroids and comets, we have reached another big step in understanding how planets are formed, too," said Gerhard Schwehm, the Rosetta mission manager at ESA.

The timing of the flyby means that the sun will shine on the asteroid, making it likely the transmitted images will be clear and concise.

Astronomers have had to work with limited data from brief flybys, such as when ESA's Giotto probe swept by Halley's Comet in 1986, photographing long canyons, broad craters and 900-metre hills.

The Steins asteroid is Rosetta's first scientific target. Its eventual destination is the comet 67/P Churyumov-Gerasimenko, which it is scheduled to reach in 2014.