Hubble Images Comet Tempel
1 Just Before Deep Impact Probe Arrives
NASA's Hubble Space Telescope has snapped an image
of Comet 9P/Tempel 1
just days before the Deep Impact spacecraft is scheduled
to rendezvous
with the comet. This image, taken on the morning
of June 30, 2005, shows
an undisturbed and quiet comet. This Advanced Camera
for Surveys (ACS)
Wide Field Camera (WFC) image of Tempel 1 shows
a slightly larger view
of the comet than was seen in Hubble images taken
with the ACS/High
Resolution Camera, which were released last week.
The Deep Impact Probe finally arrived at the comet
this morning after
a seven-month flight. Images just before and just
after the impact were
taken by a multitude of telescopes on the ground
and in space. The
space-based cameras viewing the probe-cometary impact
are the Deep
Impact spacecraft, as well as those aboard three
of NASA's Great
Observatories -- the Hubble Space Telescope, the
Spitzer Space
Telescope and Chandra X-ray Satellite. Several detectors
will continue
to view the comet in the days and weeks to come
for a glimpse of any
affect of the impact.
The observations by the Deep Impact camera and
the Hubble telescope
complement each other. The camera aboard the Deep
Impact spacecraft
provided a close-up view of the comet, from about
300 miles
away. From its distance 80 million miles away, Hubble
captured a
broader view of the encounter. The difference between
the views of
Hubble and the Deep Impact spacecraft is like that
between a satellite
image of a hurricane and a photo from the center
of the storm.
Comets are thought to be "dirty snowballs,"
porous agglomerations of
ice and rock that dwell in the frigid outer boundaries
of our solar
system. Periodically, they make their journey into
the inner solar
system as they loop around the Sun. Comets are relics
of our early
solar system, chunks of leftover material from the
formation of
the planets. Locked beneath the comet's surface
is pristine material
that astronomers want to study to learn how our
solar system formed.
The comet's name is derived from the amateur astronomer
Ernst Wilhelm
Leberecht Tempel of Marseilles, France, who discovered
Comet Tempel 1
in 1867. Little is known about the history of the
comet, except that
it is a periodic comet that orbits the Sun every
5.5 years. It has
probably made more than 100 passages through the
inner solar system.
Comet Tempel 1 is a potato-shaped object that is
8.7 miles
(14 kilometers) wide and 2.5 miles (4 kilometers)
long.
The ACS/WFC image is a composite of data taken
with blue and red
filters onboard Hubble. A quiescent comet is seen
in this pre-impact
image along with elongated star trails. As the telescope
was locked
on the movement of the comet, the background stars
left small trailed
arcs during the time the exposures were taken.
Credit: NASA, ESA, and The Hubble Heritage Team
(STScI/AURA)
Acknowledgment: P. Feldman (JHU), L. McFadden (University
of Maryland), H. Weaver (JHU APL) |
