[meteorite-list] Ceres Spots Continue to Mystify in Latest Dawn Images

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Mon, 22 Jun 2015 12:38:50 -0700 (PDT)
Message-ID: <201506221938.t5MJcorL018120_at_zagami.jpl.nasa.gov>

http://www.jpl.nasa.gov/news/news.php?feature=4633

Ceres Spots Continue to Mystify in Latest Dawn Images
Jet Propulsion Laboratory
June 22, 2015

The closer we get to Ceres, the more intriguing the distant dwarf planet
becomes. New images of Ceres from NASA's Dawn spacecraft provide more
clues about its mysterious bright spots, and also reveal a pyramid-shaped
peak towering over a relatively flat landscape.

"The surface of Ceres has revealed many interesting and unique features.
For example, icy moons in the outer solar system have craters with central
pits, but on Ceres central pits in large craters are much more common.
These and other features will allow us to understand the inner structure
of Ceres that we cannot sense directly," said Carol Raymond, deputy principal
investigator for the Dawn mission, based at NASA's Jet Propulsion Laboratory
in Pasadena, California.

Dawn has been studying the dwarf planet in detail from its second mapping
orbit, which is 2,700 miles (4,400 kilometers) above Ceres. A new view
of its intriguing bright spots, located in a crater about 55 miles (90
kilometers) across, shows even more small spots in the crater than were
previously visible.

At least eight spots can be seen next to the largest bright area, which
scientists think is approximately 6 miles (9 kilometers) wide. A highly
reflective material is responsible for these spots -- ice and salt are
leading possibilities, but scientists are considering other options, too.

Dawn's visible and infrared mapping spectrometer allows scientists to
identify specific minerals present on Ceres by looking at how light is
reflected. Each mineral reflects the range of visible and infrared-light
wavelengths in a unique way, and this signature helps scientists determine
the components of Ceres. So, as the spacecraft continues to send back
more images and data, scientists will learn more about the mystery bright
spots.

In addition to the bright spots, the latest images also show a mountain
with steep slopes protruding from a relatively smooth area of the dwarf
planet's surface. The structure rises about 3 miles (5 kilometers) above
the surface.

Ceres also has numerous craters of varying sizes, many of which have central
peaks. There is ample evidence of past activity on the surface, including
flows, landslides and collapsed structures. It seems that Ceres shows
more remnants of activity than the protoplanet Vesta, which Dawn studied
intensively for 14 months in 2011 and 2012.

Dawn is the first mission to visit a dwarf planet, and the first to orbit
two distinct targets in our solar system. It arrived at Ceres, the largest
object in the main asteroid belt between Mars and Jupiter, on March 6,
2015.

Dawn will remain in its current altitude until June 30, continuing to
take images and spectra of Ceres in orbits of about three days each. It
then will move into its next orbit at an altitude of 900 miles (1,450
kilometers), arriving in early August.

Dawn's 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:

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

and

http://www.nasa.gov/dawn

What are those unusual bright spots on Ceres? Cast your vote:

http://www.jpl.nasa.gov/dawn/world_ceres/


Media Contact

Elizabeth Landau
Jet Propulsion Laboratory, Pasadena, Calif.
818-354-6425
elizabeth.landau at jpl.nasa.gov

2015-215
Received on Mon 22 Jun 2015 03:38:50 PM PDT