Crater on Huge Asteroid Vesta Gets 3D Treatment

Dark Streaks on Huge Asteroid Vesta
This composite-color view from NASA's Dawn mission shows Cornelia Crater, streaked with dark materials, on the giant asteroid Vesta (Image credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA)

A new 3D photo from NASA's Dawn spacecraft reveals a stunning glimpse inside a massive crater on the huge asteroid Vesta. 

The new image shows dark streaks of carbon-rich material radiating out from the 9-mile-wide (15 kilometers) Cornelia Crater. The coal-black material speckles the rim and flanks of the crater, which is found in Vesta's southern half. Dawn captured the images that make up the 3D mosaic while orbiting Vesta from an altitude of 420 miles (680 km), researchers said.

The dark material is common around the edges of two enormous impact basins in the southern hemisphere of Vesta, which at 325 miles (523 km) wide is the second-largest body in the main asteroid belt between Mars and Jupiter.

These two basins, which are known as Veneneia and Rheasilvia, were likely formed by asteroids between 25 and 36 miles (40 to 60 km) wide, scientists have said. The Rheasilvia impact probably blasted out about 250,000 cubic miles (1.04 million cubic km) of material — enough to fill the Grand Canyon 1,000 times over.

These mosaic images from NASA's Dawn mission show how dark, carbon-rich materials tend to speckle the rims of smaller craters or their immediate surroundings on the giant asteroid Vesta. The image on the left is Numisia Crater and the image on the right is a shallow, unnamed crater in the Sextilia quadrangle. Image released Jan. 3, 2013. (Image credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA)

Veneneia, which apparently formed between two and three billion years ago, is about 250 miles (400 km) across. The younger Rheasilvia is even larger; at 310 miles (500 km) wide, it spans virtually all of Vesta's diameter.

A recent analysis of the carbon-rich dark stuff suggests that much of it was delivered by the object that created Veneneia, researchers said. Some of the material was then likely covered up by the massive impact that produced Rheasilvia.

Scientists think Vesta is a protoplanet left over from the solar system's early days, a building block whose progression toward full-fledged planet was halted by Jupiter's powerful gravitational pull.

The $466 million Dawn spacecraft arrived at Vesta in July 2011 and orbited the intriguing object for more than a year. In September 2012, Dawn departed for the dwarf planet Ceres, the largest resident of the asteroid belt. Dawn is slated to arrive at Ceres in early 2015.

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Mike Wall
Senior Space Writer

Michael Wall is a Senior Space Writer with and joined the team in 2010. He primarily covers exoplanets, spaceflight and military space, but has been known to dabble in the space art beat. His book about the search for alien life, "Out There," was published on Nov. 13, 2018. Before becoming a science writer, Michael worked as a herpetologist and wildlife biologist. He has a Ph.D. in evolutionary biology from the University of Sydney, Australia, a bachelor's degree from the University of Arizona, and a graduate certificate in science writing from the University of California, Santa Cruz. To find out what his latest project is, you can follow Michael on Twitter.