Commencing next July, Dawn will orbit Vesta for a year, carrying a elaborate study and becoming the 1st spacecraft ever to orbit a body in the asteroid belt. Former missions have depicted us a fistful of asteroids, but Vesta will be peculiar, scientists say.
“Vesta is going to amaze us,” said Marc Rayman, Dawn’s chief engineer at NASA’s Jet Propulsion Laboratory.
At 350 miles (565 km) across, Vesta is about a globe unto itself. It’s the second-largest body in the asteroid belt, bearing about 10 percent of the entire belt’s mass. The asteroid Ceres, so big it is believed a dwarf planet, is the only belt object greater than Vesta.
“It’s a big, rocky, terrestrial-type body more likely alike to the moon and Mercury than to the little bits of rocks we’ve flown by in the past,” Rayman said of Vesta. “For example, there’s a large crater at Vesta’s south pole, and inside the crater is a mountain bigger than asteroid Eros.”
Researchers hope Dawn’s mission will assist them interpret how planets form. Astronomers believe, after all, that Vesta was in the process of becoming a experienced planet when Jupiter disrupted its growth. The gas giant’s gravity stirred up the material in the asteroid belt so objects there could no longer coalesce.
Dawn, which of late set a record for the all-time greatest speed boost for a spacecraft engine, will start its Vesta surveys out slow. Its first orbits will be high and leisurely, and the craft will take days to loop around Vesta at altitudes of about 1,700 miles (2,735 km).
After taking pictures and gathering data from up high, Dawn will spiral down to lower and lower orbits, eventually settling in a little more than 100 miles (nearly 161 km) high lower than satellites orbiting Earth.
The great Vesta view Dawn gets won’t be restricted to astronomers: Researchers will quickly combine the images the probe captures into a movie, allowing the mission team and public all to vicariously ride along.
After a year orbiting Vesta, Dawn will move on to take a look at the asteroid belt’s largest body: the dwarf planet Ceres.
Dawn’s mission follows on the heels of several others, as astronomers have become increasingly interested lately in near-Earth objects.
For example, the European Space Agency’s Rosetta spacecraft just beamed back pictures of Lutetia, which at 62 miles (100 km) wide is the largest asteroid yet visited by a spacecraft.
And in June, the Japanese space agency’s Hayabusa probe returned to Earth after a seven-year journey to the asteroid Itokawa. Hayabusa’s goal was to return samples of an asteroid to Earth, which would be a first and it may have done so, though the jury is still out.