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Feature/Overview
and Objectives
Dawn
Dictionary
Why Ceres and Vesta?
Technology
Orbit Visualization Tools:
Ceres
Vesta
Archive
Podcasts from 2007 Dawn Launch Educator Conference
+ Cratering Lecture
+ 'What Makes a Planet?' Lecture
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The Great Planet Debate: Science as Process
A Scientific Conference & Educator Workshop
Top scientists and educators will convene in Maryland this summer to explore a basic, but controversial, question: What is a planet?
The Great Planet Debate (GPD) conference includes two days (August 14-15) of scientific sessions to discuss and debate the processes leading to planet formation and the characteristics and criteria used to define and categorize planets. An open-to-the-public debate between Dr. Mark Sykes of the Planetary Science Institute and Dr. Neil deGrasse Tyson of the American Museum of Natural History is scheduled on the afternoon of August 14th.
An educator's workshop follows on the third day (August 16th) to provide a forum on how the planet debate can be used to spark scientific inquiry in the classroom.
+ Read this press release for further background on the GPD Conference
+ Click here to see the official GPD poster
+ Learn more about the GPD Conference
+ The Planet Debate Continues: Read full article from Science magazine
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Image of Vesta
Credit: Hubble SpaceTelescope |
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Hubble Images of Asteroids Help Astronomers Prepare for Spacecraft Visit
To prepare for the Dawn spacecraft’s visit to Vesta, astronomers used Hubble’s Wide Field Planetary Camera 2 to snap new images of the asteroid. The image at left was taken on May 14 and 16, 2007. Using Hubble, astronomers mapped Vesta’s southern hemisphere, a region dominated by a giant impact crater formed by a collision billions of years ago. The crater is 285 miles (456 kilometers) across, which is nearly equal to Vesta's 330-mile (530-kilometer) diameter. If Earth had a crater of proportional size, it would fill the Pacific Ocean basin. The impact broke off chunks of rock, producing more than 50 smaller asteroids that astronomers have nicknamed “vestoids.” The collision also may have blasted through Vesta’s crust. Vesta is about the size of Arizona.
+ Read more
+ See Vesta Gallery
Overview
Dawn's goal is to achieve an understanding
of the conditions and processes acting at the solar system's
earliest epoch. Dawn investigates the internal structure,
density and homogeneity of two complementary protoplanets,
1 Ceres and 4 Vesta, that have remained intact since their
formation, by measuring their mass, shape, volume and spin
rate with both imagery, laser altimetry and gravity. Dawn
records the protoplanets' elemental
and mineral composition to determine their thermal history
and evolution and provides context for meteorites (asteroid
samples already in hand). Dawn images Ceres and Vesta's surfaces
to determine their bombardment and tectonic history, uses
gravity and spin state to limit the size of
any metallic core, and infrared and gamma ray spectrometry
to search for water-bearing minerals.
Measurements Objectives:
- Internal structure, density and homogeneity of two complementary
protoplanets,
1 Ceres and 4 Vesta, one wet and one dry
- Determine shape, size, composition and mass
- Surface morphology, cratering
- Determine thermal history and size of core
- Understand role of water in controlling asteroid evolution
- Test the current paradigm of Vesta as the howardite,
eucrite, and diogenite (HED) parent body and determine
which, if any, meteorites come from Ceres
- Provide a geologic context for HEDs
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See archived Science features
Dawn's Early Light
The Science team newsletter, Dawn's Early Light, has been established to keep members of the scientific community informed about the Dawn mission. Current and past issues are available on line. |
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accountability report