The European Space Agency has taken the closest look yet at the asteroid Lutetia in an extraordinary quest, 280 million miles from Earth in outer space between Mars and Jupiter.
The comet-chaser Rosetta transmitted its first pictures from the largest asteroid ever visited by a satellite Saturday night, after flying by Lutetia at a distance as close as 1,900 miles (3,200 kilometers).
"These are fantastic and exciting pictures," space agency scientist Rita Schulz said in a webcast presentation from the ESA operations center in Darmstadt, Germany. She said it would take several weeks before all 400 pictures and the other data from the high-precision instruments aboard Rosetta would come through to Earth.
"I am a very happy man," ESA manager David Southwood said. "It is a great day for European science and for world science."
Though Lutetia was discovered 150 years ago, for a long time it was little more than a point of light to those on Earth. It's only been recently that high-resolution, ground-based imaging has given a vague view of the asteroid, the agency said.
"At the moment we know very little about it," Schulz said.
Lutetia is believed to be 83.3 miles (134 kilometers) in diameter with a "pronounced elongation," but scientists have been puzzled as to what type of asteroid it is — a "primitive" one containing carbon compounds, or a metallic asteroid.
"We are now going to get the details of this asteroid, which is very important," Schulz said. "There will be a lot of science coming from that mission."
Scientists hope to find clues in the information and images gathered by Rosetta that will reveal more about the history of comets and asteroids and of the solar system, Schulz said.
For Rosetta, examining Lutetia and other asteroids is only a side event on its long journey to Comet 67P/Churyumov-Gerasimenko — the mission's destination, said project manager Gerhard Schwehm.
Rosetta was launched in 2004 and has taken pictures of Earth, Mars and the asteroid Steins during past flybys. It is expected to reach Churyumov-Gerasimenko in 2014.
Though the wait is long, scientists are certain it is going to be worthwhile, Schwehm said.
"We want to study the material out of which the planets formed," he said. This is possible only close up, he said.
This report was supplemented by msnbc.com.