[meteorite-list] Geologic Maps of Vesta from NASA's Dawn Mission Published

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Tue, 18 Nov 2014 10:30:48 -0800 (PST)
Message-ID: <201411181830.sAIIUmRQ000858_at_zagami.jpl.nasa.gov>

http://www.jpl.nasa.gov/news/news.php?feature=4381

Geologic Maps of Vesta from NASA's Dawn Mission Published
Jet Propulsion Laboratory
November 17, 2014

Images from NASA's Dawn Mission have been used to create a series of
high-resolution geological maps of the large asteroid Vesta, revealing
the variety of surface features in unprecedented detail. These maps are
included with a series of 11 scientific papers published this week in a
special issue of the journal Icarus.

Geological mapping is a technique used to derive the geologic history of
a planetary object from detailed analysis of surface morphology,
topography, color and brightness information. A team of 14 scientists
mapped the surface of Vesta using Dawn spacecraft data, led by three
NASA-funded participating scientists: David A. Williams of Arizona State
University, Tempe; R. Aileen Yingst of the Planetary Science Institute,
Tucson, Arizona; and W. Brent Garry of the NASA Goddard Spaceflight
Center, Greenbelt, Maryland.

"The geologic mapping campaign at Vesta took about two-and-a-half years
to complete, and the resulting maps enabled us to recognize a geologic
timescale of Vesta for comparison to other planets," said Williams.

Scientists discovered through these maps that impacts from several large
meteorites have shaped Vesta's history. Asteroids like Vesta are
remnants of the formation of the solar system, giving scientists a peek
at its history. Asteroids could also harbor molecules that are the
building blocks of life and reveal clues about the origins of life on
Earth.

The geologic mapping of Vesta is enabled by images obtained by the
framing camera provided by the Max Planck Institute for Solar System
Research of the German Max Planck Society and the German Aerospace
Center. This camera takes panchromatic images and seven bands of
color-filtered images. Stereo photos are used to create topographic
models of the surface that aid in the geologic interpretation.

Vesta's geologic timescale is determined by the sequence of large impact
events, primarily by the Veneneia and Rheasilvia impacts in Vesta's
early history and the Marcia impact in its late history. The oldest
crust on Vesta pre-dates the Veneneia impact.The relative timescale is
supplemented by model-based absolute ages from two different approaches
that apply crater statistics to date the surface.

"This mapping was crucial for getting a better understanding of Vesta's
geological history, as well as providing context for the compositional
information that we received from other instruments on the spacecraft:
the visible and infrared (VIR) mapping spectrometer and the gamma-ray
and neutron detector (GRaND)," said Carol Raymond, Dawn's deputy
principal investigator at NASA's Jet Propulsion Laboratory in Pasadena,
California.

The objective of NASA's Dawn mission is to characterize the two most
massive objects in the main asteroid belt between Mars and Jupiter -
Vesta and the dwarf planet Ceres. The spacecraft launched in 2007.
Vesta, orbited by the Dawn spacecraft between July 2011 and September
2012, was thought to be the source of a unique set of basaltic
meteorites (called HEDs, for howardite-eucrite-diogenite), and Dawn
confirmed the Vesta-HED connection.

The Dawn spacecraft is currently on its way to Ceres, the largest object
in the asteroid belt. Dawn will arrive at Ceres in March 2015.

Dawn uses ion propulsion in spiraling trajectories to travel from Earth
to Vesta, orbit Vesta and then continue on to orbit the dwarf planet
Ceres. Ion engines use very small amounts of onboard fuel, enabling a
mission that would be unaffordable or impossible without them.

JPL manages the Dawn mission 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.
The University of California at Los Angeles (UCLA) is responsible for
overall Dawn mission science. Orbital Sciences Corp. in Dulles,
Virginia, designed and built the spacecraft. The German Aerospace
Center, the Max Planck Institute for Solar System Research, the Italian
Space Agency and the Italian National Astrophysical Institute are
international partners on the mission team.

For more information about Dawn, visit:

http://www.nasa.gov/dawn


Media Contact

Elizabeth Landau
NASA's Jet Propulsion Laboratory, Pasadena, Calif.
818-354-6425
Elizabeth.Landau at jpl.nasa.gov

Robert Burnham
Arizona State University, Tempe, Ariz.
480-458-8207
Robert.Burnham at asu.edu

2014-399
Received on Tue 18 Nov 2014 01:30:48 PM PST