Detail View: NASA Astronomy Picture of the Day Collection: An Orbiting Iceberg

Title: 
An Orbiting Iceberg
Explanation: 
A comet nucleus [ http://antwrp.gsfc.nasa.gov/apod/lib/glossary.html#comet ], formed from the primordial stuff of the solar system, resembles a very dirty iceberg. Orbiting far from our Sun, it can remain frozen, preserved for billions of years. Occasionally, a chance gravitational encounter will alter this distant orbit and send the nucleus plummeting towards the inner solar system. In 1986, the European spacecraft Giotto [ http://nssdc.gsfc.nasa.gov/planetary/giotto.html ] visited the nucleus of Halley's comet [ http://seds.lpl.arizona.edu/billa/tnp/halley.html ] as it approached the sun. Data from Giotto's cameras were used to produce this enhanced image which shows surface features on the dark nucleus against the bright background of clouds of gasses produced as the icy material was vaporized by the Sun's heat. The potato shaped nucleus measures about 10 miles across. Tomorrow's picture: Venus Unveiled
Credit and Copyright: 
European Space Agency [ http://www.esrin.esa.it/ ], Giotto Camera Team.
facet_when: 
1986
facet_where: 
Arizona
facet_what: 
Giotto
facet_when_year: 
1986
original url: 
http://antwrp.gsfc.nasa.gov/apod/ap950821.html
UID: 
SPD-APOD-ap950821