CONTACT: Ray Villard
Space Telescope Science Institute, Baltimore, MD
(Phone: 410-338-4514; E-mail: villard@stsci.edu)
Michael Purdy
Johns Hopkins University, Baltimore, MD
(Phone: 410-516-7160; E-mail: mcp@jhu.edu)
Hubble Discovers Missing Pieces of Comet Linear
NASA’s Hubble Space Telescope has discovered a small armada of
“mini-comets” left behind from what some astronomers had
prematurely thought was a total disintegration of Comet LINEAR’s
solid nucleus, following its passage around the Sun on July 26.
Though comets have been known to break apart and vanish before,
for the first time astronomers are getting a close-up view of the
dismantling of a comet’s nucleus due to warming by the Sun. The
results support the popular theory that comet nuclei are really
made up of a cluster of smaller icy bodies called “cometesimals”.
The breakup of a comet tells scientists how it is assembled. Its
fundamantal building blocks, the cometesimals, were built up from
micron-sized grains of dust in the early solar system.
Image caption:
In one stunning Hubble picture the fate of the mysteriously vanished solid nucleus of Comet LINEAR has been settled. The Hubble picture shows that the comet nucleus has been reduced to a shower of glowing “mini-comets” resembling the fiery fragments from an exploding aerial firework. This is the first time astronomers have ever gotten a close-up look at what may be the smallest building blocks of cometary nuclei, the icy solid pieces called “cometesimals”, which are thought to be less than 100 feet across. The farthest fragment to the left, which is now very faint, may be the remains of the parent nucleus that fragmented into the cluster of smaller pieces to the right. The comet broke apart around July 26, when it made its closest approach to the Sun. The picture was taken with Hubble’s Wide Field Planetary Camera 2 on August 5, 2000, when the comet was at a distance of 64 million miles (102 kilometers) from Earth.
More photos at:
