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Tag: Vesta

  • Giant Asteroid “Speckles” Analyzed by NASA’s Dawn

    New images released by NASA have provided scientists their best view yet of the black spots seen on the surface of the giant asteroid Vesta. The new research suggests that the protoplanet may have received the carbon-rich material through large impacts with other objects.

    The new study, published in the journal Icarus, is the most complete analysis of the material yet. Researchers observed that the dark material appears around the edges of giant impact basins on the asteroid’s southern hemisphere, suggesting that the material was deposited by the impact that created the older of the two basins.

    “First, we created a map showing the distribution of dark material on Vesta using the framing camera data and found something remarkable,” said Lucille Le Corre, co-author of the study at the Max Planck Institute for Solar System Research.

    The map showed that the material had been spread by a slow impacting asteroid that created the Veneneia basin some 2 to 3 billion years ago. The material was then covered by a subsequent impact that created the younger basin.

    The images were taken by NASA’s Dawn mission, which completed its investigations of Vesta in September 2012 and is currently on-route to the dwarf planet Ceres. In the past few months, research based on Dawn mission data has uncovered strange gullies along the walls of Vesta craters and the fact that Vesta’s surface is constantly “stirring” and presenting a young sppearance.

    “The aim of our efforts was not only to reconstruct Vesta’s history, but also to understand the conditions in the early solar system,” said Holger Sierks, co-investigator on the Dawn mission at the Max Planck Institute.

    (Image courtesy NASA/JPL-Caltech/UCLA/MPS/DLR/IDA)

  • NASA Finds Mysterious Gullies on Asteroid Vesta’s Surface

    NASA’s Dawn mission has returned images from the giant asteroid Vesta that scientists say include long, narrow gullies along the walls of relatively young craters.

    The discovery has revealed a mystery that scientists are now trying to solve. The images from Dawn show two different types of gullies. Some are straight chutes, while others wind about and end in what NASA is calling “lobe-shaped” deposits.

    “The straight gullies we see on Vesta are textbook examples of flows of dry material, like sand, that we’ve seen on Earth’s moon and we expected to see on Vesta,” said Jennifer Scully, a Dawn team member at the University of California, Los Angeles. “But these sinuous gullies are an exciting, unexpected find that we are still trying to understand.”

    The “sinuous” gullies are longer, narrower, and curvier than the others. The also begin from V-shaped, collapsed regions researchers have described as “alcoves.” The current hypothesis is that two different processes formed the different gullies.

    “On Earth, similar features – seen at places like Meteor Crater in Arizona – are carved by liquid water,” said Christopher Russell, Dawn’s principal investigator at UCLA. “On Mars, there is still a debate about what has caused them. We need to analyze the Vesta gullies very carefully before definitively specifying their source.”

    Researchers are looking to Earth and Mars for clues about Vesta’s gullies, but mystery still remains. Scientists have been debating the explanation for Mars’ gullies for years. Some possible causes include liquid water and carbon-dioxide frost that causes fresh flows of Martian sand.

    (Image courtesy NASA/JPL-Caltech/UCLA/MPS/DLR/IDA)