Rosetta To Drop By, Looking For Rubble
Sydney Morning Herald
Friday September 5, 2008
AS WORLDS go, it is tiny, little more than a lump of rubble left over from the birth of the solar system. But the voyage to reach it has taken 4 1/2 years.
Early tomorrow the European space probe Rosetta will sweep within 800 kilometres of an asteroid called Steins. The asteroid, just 4.6 kilometres across, orbits the sun between Mars and Jupiter, 360 million kilometres from Earth. Finding it had been an achievement, said John Holt, a former Telstra engineer who leads the team operating the New Norcia tracking station, near Perth, owned by the European Space Agency. Today New Norcia will beam up final commands, ensuring Rosetta is on course for the 8.6 kilometres-a-second fly-past. If all goes well, the station will begin receiving pictures beamed back by the probe over the weekend. "Ours is the prime tracking facility controlling the mission," Mr Holt said. "We are the central link between the Earth and the spacecraft."Rosetta is so distant that signals travelling at the speed of light take 20 minutes to arrive. "It is quite difficult just to estimate where the spacecraft is," he said. "To try to manoeuvre to within 800 kilometres of the asteroid is quite incredible."Astronomers believe this body of rock will provide clues to how the planets formed more than 4.6 billion years ago.
© 2008 Sydney Morning Herald