[meteorite-list] Dawn Captures Sharper Images of Ceres

From: lebofsky at lpl.arizona.edu <lebofsky_at_meteoritecentral.com>
Date: Tue, 17 Feb 2015 19:53:45 -0700
Message-ID: <0b6648534f7c45fdce613f434708b798.squirrel_at_webmail.lpl.arizona.edu>

Hi Graham:

The average albedo of Ceres is about 0.09, i.e., it reflects 9% of the
light. Sort of gray. This is from telescopic observations, not Dawn. I
think that makes it at least 50% more reflective than Comet
67P/Churyumov?Gerasimenko. Most "dark" asteroids have albedos of about
0.05. The best I can get out of anyone I have asked (as of a week or two
ago) is that the "white" spots are only a little more reflective than the
rest of Ceres.

The bottom line is that I do not know if these images are well-calibrated.
Time will tell.

Maybe someone on the list knows more and is able to clarify this.

The number and size of the craters surprises me.

Larry

> Yes Larry...been waiting a long time to find out what Ceres looks
> like....really looking forward to the next weeks of more detail and
> the analysis of data...and of course the decisions about those whiter
> areas....I wonder what the actual brightness is...perhaps it is just
> the camera correction and the surface is mostly very dark...anyone
> know?
>
> Graham
>
> On Tue, Feb 17, 2015 at 10:36 PM, <Lebofsky at lpl.arizona.edu> wrote:
>> Graham:
>>
>> I am amazed by how cratered ("old") the surface looks. I am still
>> personally very interested in how bright the whitish areas actually are.
>> Icy?
>>
>> Larry
>>
>>
>>> Wonderful!...now seeing good detail...can't wait for a closer look and
>>> the data analysis.
>>>
>>> Graham
>>>
>>> On Tue, Feb 17, 2015 at 4:44 PM, Ron Baalke via Meteorite-list
>>> <meteorite-list at meteoritecentral.com> wrote:
>>>>
>>>> http://www.jpl.nasa.gov/news/news.php?feature=4485
>>>>
>>>> Dawn Captures Sharper Images of Ceres
>>>> Jet Propulsion Laboratory
>>>> February 17, 2015
>>>>
>>>> Craters and mysterious bright spots are beginning to pop out in the
>>>> latest images of Ceres from NASA's Dawn spacecraft. These images,
>>>> taken
>>>> Feb. 12 at a distance of 52,000 miles (83,000 kilometers) from the
>>>> dwarf
>>>> planet, pose intriguing questions for the science team to explore as
>>>> the
>>>> spacecraft nears its destination.
>>>>
>>>> The image is available at:
>>>>
>>>> http://www.jpl.nasa.gov/spaceimages/details.php?id=PIA19056
>>>>
>>>> "As we slowly approach the stage, our eyes transfixed on Ceres and her
>>>> planetary dance, we find she has beguiled us but left us none the
>>>> wiser," said Chris Russell, principal investigator of the Dawn
>>>> mission,
>>>> based at UCLA. "We expected to be surprised; we did not expect to be
>>>> this puzzled."
>>>>
>>>> Dawn will be gently captured into orbit around Ceres on March 6. As
>>>> the
>>>> spacecraft delivers better images and other data, the science team
>>>> will
>>>> be investigating the nature and composition of the dwarf planet,
>>>> including the nature of the craters and bright spots that are coming
>>>> into focus. The latest images, which have a resolution of 4.9 miles
>>>> (7.8
>>>> kilometers) per pixel, represent the sharpest views of Ceres to date.
>>>>
>>>> The spacecraft explored the giant asteroid Vesta for 14 months during
>>>> 2011 and 2012. Scientists gained numerous insights about the
>>>> geological
>>>> history of this body and saw its cratered surface in fine detail. By
>>>> comparing Vesta and Ceres, they will develop a better understanding of
>>>> the formation of the solar system.
>>>>
>>>> Dawn's mission to Vesta and Ceres 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., of Dulles,
>>>> Virginia, designed and built the spacecraft. JPL is managed for NASA
>>>> by
>>>> the California Institute of Technology in Pasadena. The framing
>>>> cameras
>>>> were provided by the Max Planck Institute for Solar System Research,
>>>> Gottingen, Germany, with significant contributions by the German
>>>> Aerospace Center (DLR) Institute of Planetary Research, Berlin, and in
>>>> coordination with the Institute of Computer and Communication Network
>>>> Engineering, Braunschweig. The visible and infrared mapping
>>>> spectrometer
>>>> was provided by the Italian Space Agency and the Italian National
>>>> Institute for Astrophysics, built by Selex ES, and is managed and
>>>> operated by the Italian Institute for Space Astrophysics and
>>>> Planetology, Rome. The gamma ray and neutron detector was built by Los
>>>> Alamos National Laboratory, New Mexico, and is operated by the
>>>> Planetary
>>>> Science Institute, Tucson, Arizona.
>>>>
>>>> For more information about Dawn, visit:
>>>>
>>>> http://dawn.jpl.nasa.gov
>>>>
>>>> Media Contact
>>>>
>>>> Elizabeth Landau
>>>> NASA's Jet Propulsion Laboratory, Pasadena, Calif.
>>>> 818-354-6425
>>>> Elizabeth.Landau at jpl.nasa.gov
>>>>
>>>> 2015-061
>>>> ______________________________________________
>>>>
>>>> Visit the Archives at http://www.meteorite-list-archives.com
>>>> Meteorite-list mailing list
>>>> Meteorite-list at meteoritecentral.com
>>>> https://pairlist3.pair.net/mailman/listinfo/meteorite-list
>>> ______________________________________________
>>>
>>> Visit the Archives at http://www.meteorite-list-archives.com
>>> Meteorite-list mailing list
>>> Meteorite-list at meteoritecentral.com
>>> https://pairlist3.pair.net/mailman/listinfo/meteorite-list
>>>
>>
>>
>
Received on Tue 17 Feb 2015 09:53:45 PM PST