The spacecraft this week completed its gentle spiral into its new science orbit, known as the high altitude mapping orbit (HAMO), to obtain an even closer view of the asteroid.
In this orbit, the average distance from the spacecraft to the Vesta surface is 420 miles (680 kilometers), which is four times closer than the previous survey orbit.
The spacecraft’s orbit around the asteroid will take a little over 12 hours, compared to three days previously. HAMO is scheduled to last about 30 Earth days, during which Dawn will circle Vesta more than 60 times.
When Dawn is over Vesta’s dayside, it will point its science instruments to the giant asteroid and acquire data, and when the spacecraft flies over the nightside, it will beam that data back to Earth.
Scientists will combine the pictures to create topographic maps, revealing the heights of mountains, the depths of craters and the slopes of plains. This will help scientists understand the geological processes that shaped Vesta.
“The team has been in awe of what they have seen on the surface of Vesta,” said Christopher Russell, Dawn principal investigator, at UCLA. “We are sharing those discoveries with the greater scientific community and with the public.”
Dawn launched in September 2007 and arrived at Vesta in July 2011. Following a year at Vesta, the spacecraft will depart in July 2012 for Ceres, where it will arrive in 2015
Meanwhile, NASA has announced that a Dawn mission news conference will be held Monday, Oct. 3, 2011 at 12:15 p.m. CEST (3:15 a.m. PDT/6:15 a.m. EDT). The conference will be streamed live online.
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