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Vesta vistas streaming in

Full-frame image of Vesta

NASA's Dawn spacecraft obtained this image of the giant asteroid Vesta with its framing camera on July 24, 2011. It was taken from a distance of about 5,200 kilometres. Dawn will spend a year orbiting the body. After that, the next stop on its itinerary will be an encounter with the dwarf planet Ceres.

  • Vesta is one of the largest asteroids
  • Dawn mission will spend a year investigating it
  • First close-up images now coming in

AFTER TRAVELLING NEARLY FOUR YEARS and 2.8 billion kilometres, NASA’s Dawn spacecraft has been captured by the Vesta’s gravity. The giant asteroid and its new companion are currently approximately 184 million kilometres from Earth.

The first spacecraft to orbit an object in the main asteroid belt, Dawn is now spiralling down towards its first of four intensive science orbits. That initial orbit of the rocky world—to begin on August 11, at an altitude of nearly 2,700 kilometres—will provide in-depth analysis of the asteroid.

Vesta, 530 kilometres wide, is the brightest object in the asteroid belt as seen from Earth and is thought to be the source of a large number of meteorites that fall to Earth.

Snowman craters on Vesta

A set of three craters, informally nicknamed 'Snowman' by the camera's team members, is located in the northern hemisphere of Vesta.

Craters on Vesta

Various craters are visible in this image of part of the southern equatorial region of the giant asteroid Vesta.

The smallest rocky ‘planet’

Images from Dawn’s framing camera, taken for navigation purposes and as preparation for scientific observations, are revealing the first surface details of the giant asteroid. These images go all the way around Vesta, since the giant asteroid turns on its axis once every five hours and 20 minutes.

“Now that we are in orbit around one of the last unexplored worlds in the inner Solar System, we can see that it’s a unique and fascinating place,” said Marc Rayman, Dawn’s chief engineer and mission manager at NASA’s Jet Propulsion Laboratory.

Download a Vesta wallpaper image, 1024 x 1024 pixels.

“We have been calling Vesta the smallest terrestrial planet,” said Chris Russell, Dawn’s principal investigator at UCLA. “The latest imagery provides much justification for our expectations.”

“They show that a variety of processes were once at work on the surface of Vesta and provide extensive evidence for Vesta’s planetary aspirations.”

Here’s a short video showing the different faces of Vesta as it rotates:

“The new observations of Vesta are an inspirational reminder of the wonders unveiled through ongoing exploration of our Solar System,” said Jim Green, planetary division director at NASA Headquarters in Washington.

Dawn launched in September 2007. Following a year at Vesta, the spacecraft will depart in July 2012 for Ceres, where it will arrive in 2015.

More information: NASA’s Dawn mission pages

Adapted from information issued by NASA. Images courtesy NASA / JPL-Caltech / UCLA / MPS / DLR / IDA.

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Dawn mission is a rock star

Latest Image of Vesta Captured by Dawn

NASA's Dawn spacecraft obtained this image with its framing camera on July 17, 2011. It was taken from a distance of about 15,000 kilometres from the protoplanet Vesta. Each pixel in the image corresponds to roughly 1.4 kilometres.

NASA’S DAWN SPACECRAFT has returned the first close-up image after beginning its orbit around the giant asteroid Vesta. On Friday, July 15, Dawn became the first probe to enter orbit around an object in the main asteroid belt between Mars and Jupiter.

The image—taken for navigation purposes—shows Vesta in greater detail than ever before. When Vesta captured Dawn into its orbit, there were approximately 16,000 kilometres between the spacecraft and asteroid.

Vesta is 530 kilometres in diameter and the second most massive object in the asteroid belt. Vesta and Dawn are currently approximately 188 million kilometres from Earth.

The onslaught of eons

Ground- and space-based telescopes have obtained images of Vesta for about two centuries, but they have not been able to see much detail on its surface.

“We are beginning the study of arguably the oldest extant primordial surface in the solar system,” said Dawn principal investigator Christopher Russell from the University of California, Los Angeles.

“This region of space has been ignored for far too long,” he added. “So far, the images received to date reveal a complex surface that seems to have preserved some of the earliest events in Vesta’s history, as well as logging the onslaught that Vesta has suffered in the intervening eons.”

Comparative sizes of eight asteroids

This composite image shows the comparative sizes of eight asteroids visited by spacecraft. Until now, Lutetia, with a diameter of 130 kilometres, was the largest asteroid visited, which occurred during a flyby of the Rosetta spacecraft in July 2010.

High thrust

The Dawn team will begin gathering science data in August. Observations will provide unprecedented data to help scientists understand the earliest chapter of our Solar System. The data also will help pave the way for future human space missions.

After travelling nearly four years and 2.8 billion kilometres, Dawn accomplished the largest propulsive acceleration of any spacecraft, with a change in velocity of more than 6.7 kilometres per second, courtesy of its ion engines. The engines expel ions (electrically charged atoms) to create continuous thrust and provide higher spacecraft speeds than any other technology currently available.

“Dawn slipped gently into orbit with the same grace it has displayed during its years of ion thrusting through interplanetary space,” said Marc Rayman, Dawn chief engineer and mission manager at NASA’s Jet Propulsion Laboratory.

“It is fantastically exciting that we will begin providing humankind its first detailed views of one of the last unexplored worlds in the inner solar system.”

Searching for moons

Although orbit capture is complete, the approach phase will continue for about three weeks. During approach, the Dawn team will continue a search for possible moons around the asteroid; obtain more images for navigation; observe Vesta’s physical properties; and obtain calibration data.

In addition, navigators will measure the strength of Vesta’s gravitational tug on the spacecraft to compute the asteroid’s mass with much greater accuracy than has been previously available. That will allow them to refine the time of orbit insertion.

Dawn will spend one year orbiting Vesta, then travel to a second destination, the dwarf planet Ceres, arriving in February 2015.

More information

Dawn mission

Dawn on Twitter

Adapted from information issued by NASA / JPL. Images courtesy NASA / JPL-Caltech / UCLA / MPS / DLR / IDA / JAXA / ESA.

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