[meteorite-list] New Details on Ceres Seen in Dawn Images
From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Fri, 15 Jan 2016 11:05:29 -0800 (PST)
New Details on Ceres Seen in Dawn Images
Jet Propulsion Laboratory
January 12, 2016
Features on dwarf planet Ceres that piqued the interest of scientists
throughout 2015 stand out in exquisite detail in the latest images from
NASA's Dawn spacecraft, which recently reached its lowest-ever altitude
Dawn took these images near its current altitude of 240 miles (385 kilometers)
from Ceres, between Dec. 19 and 23, 2015.
Kupalo Crater, one of the youngest craters on Ceres, shows off many fascinating
attributes at the high image resolution of 120 feet (35 meters) per pixel.
The crater has bright material exposed on its rim, which could be salts,
and its flat floor likely formed from impact melt and debris. Researchers
will be looking closely at whether this material is related to the "bright
spots" of Occator Crater. Kupalo, which measures 16 miles (26 kilometers)
across and is located at southern mid-latitudes, is named for the Slavic
god of vegetation and harvest.
"This crater and its recently-formed deposits will be a prime target of
study for the team as Dawn continues to explore Ceres in its final mapping
phase," said Paul Schenk, a Dawn science team member at the Lunar and
Planetary Institute, Houston.
Dawn's low vantage point also captured the dense network of fractures
on the floor of 78-mile-wide (126-kilometer-wide) Dantu Crater. One of
the youngest large craters on Earth's moon, called Tycho, has similar
fractures. This cracking may have resulted from the cooling of impact
melt, or when the crater floor was uplifted after the crater formed.
A 20-mile (32-kilometer) crater west of Dantu is covered in steep slopes,
called scarps, and ridges. These features likely formed when the crater
partly collapsed during the formation process. The curvilinear nature
of the scarps resembles those on the floor of Rheasilvia, the giant impact
crater on protoplanet Vesta, which Dawn orbited from 2011 to 2012.
Dawn's other instruments also began studying Ceres intensively in mid-December.
The visible and infrared mapping spectrometer is examining how various
wavelengths of light are reflected by Ceres, which will help identify
minerals present on its surface.
Dawn's gamma ray and neutron detector (GRaND) is also keeping scientists
busy. Data from GRaND help researchers understand the abundances of elements
in Ceres' surface, along with details of the dwarf planet's composition
that hold important clues about how it evolved.
The spacecraft will remain at its current altitude for the rest of its
mission, and indefinitely afterward. The end of the prime mission will
be June 30, 2016.
"When we set sail for Ceres upon completing our Vesta exploration, we
expected to be surprised by what we found on our next stop. Ceres did
not disappoint," said Chris Russell, principal investigator for the Dawn
mission, based at the University of California, Los Angeles. "Everywhere
we look in these new low- altitude observations, we see amazing landforms
that speak to the unique character of this most amazing world."
Dawn is the first mission to visit a dwarf planet, and the first mission
outside the Earth-moon system to orbit two distinct solar system targets.
After orbiting Vesta for 14 months in 2011 and 2012, it arrived at Ceres
on March 6, 2015.
Dawn's mission is managed by the Jet Propulsion Laboratory 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
More information about Dawn is available at the following sites:
Jet Propulsion Laboratory, Pasadena, Calif.
elizabeth.landau at jpl.nasa.gov
Received on Fri 15 Jan 2016 02:05:29 PM PST