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

[Ron Baalke]

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