• Dawn Identifies Age of Ceres' Brightest Area

    From baalke@1:2320/100 to sci.space.news on Mon Mar 20 20:08:52 2017
    From Newsgroup: sci.space.news


    https://www.jpl.nasa.gov/news/news.php?feature=6766

    Dawn Identifies Age of Ceres' Brightest Area
    Jet Propulsion Laboratory
    March 8, 2017

    The bright central area of Ceres' Occator Crater, known as Cerealia Facula,
    is approximately 30 million years younger than the crater in which it
    lies, according to a new study in the Astronomical Journal. Scientists
    used data from NASA's Dawn spacecraft to analyze Occator's central dome
    in detail, concluding that this intriguing bright feature on the dwarf
    planet is only about 4 million years old -- quite recent in terms of geological

    history.

    Researchers led by Andreas Nathues at the Max Planck Institute for Solar System Research (MPS) in Gottingen, Germany, analyzed data from two instruments

    on board NASA's Dawn spacecraft: the framing camera, and the visible and infrared mapping spectrometer.

    The new study supports earlier interpretations from the Dawn team that
    this reflective material -- comprising the brightest area on all of Ceres
    -- is made of carbonate salts, although it did not confirm a particular
    type of carbonate previously identified. The secondary, smaller bright
    areas of Occator, called Vinalia Faculae, are comprised of a mixture of carbonates and dark material, the study authors wrote.

    New evidence also suggests that Occator's bright dome likely rose in a
    process that took place over a long period of time, rather than forming
    in a single event. They believe the initial trigger was the impact that
    dug out the crater itself, causing briny liquid to rise closer to the
    surface. Water and dissolved gases, such as carbon dioxide and methane,
    came up and created a vent system. These rising gases also could have
    forced carbonate-rich materials to ascend toward the surface. During this period, the bright material would have erupted through fractures, eventually forming the dome that we see today.

    Read more from MPS

    The spacecraft is currently on its way to a high-altitude orbit of 12,400 miles (20,000 kilometers), and to a different orbital plane. In late spring, Dawn will view Ceres in "opposition," with the sun directly behind the spacecraft. By measuring details of the brightness of the salt deposits
    in this new geometry, scientists may gain even more insights into these captivating bright areas.

    The Dawn mission is managed by JPL for NASA's Science Mission Directorate
    in Washington. Dawn is a project of the directorate's Discovery Program, managed by NASA's Marshall Space Flight Center in Huntsville, Alabama.
    UCLA is responsible for overall Dawn mission science. Orbital ATK Inc.,
    in Dulles, Virginia, designed and built the spacecraft. The German Aerospace Center, Max Planck Institute for Solar System Research, Italian Space
    Agency and Italian National Astrophysical Institute are international
    partners on the mission team. For a complete list of mission participants, visit:

    http://dawn.jpl.nasa.gov/mission

    More information about Dawn is available at the following sites:

    http://www.nasa.gov/dawn

    http://dawn.jpl.nasa.gov


    News Media Contact
    Elizabeth Landau
    Jet Propulsion Laboratory, Pasadena, Calif.
    818-354-6425
    elizabeth.landau@jpl.nasa.gov

    2017-059

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