A Million Comet Pieces
(poster version)
This infrared image from NASA's Spitzer Space Telescope shows the broken
Comet 73P/Schwassman-Wachmann 3 skimming along a trail of debris left
during its multiple trips around the sun. The flame-like objects are the
comet's fragments and their tails, while the dusty comet trail is the line
bridging the fragments.
Comet 73P /Schwassman-Wachmann 3 began to splinter apart in 1995 during
one of its voyages around the sweltering sun. Since then, the comet has
continued to disintegrate into dozens of fragments, at least 36 of which
can be seen here. Astronomers believe the icy comet cracked due the
thermal stress from the sun.
The Spitzer image provides the best look yet at the trail of debris left
in the comet's wake after its 1995 breakup. The observatory's infrared
eyes were able to see the dusty comet bits and pieces, which are warmed
by sunlight and glow at infrared wavelengths. This comet debris ranges in
size from pebbles to large boulders. When Earth passes near this rocky
trail every year, the comet rubble burns up in our atmosphere, lighting up
the sky in meteor showers. In 2022, Earth is expected to cross close to
the comet's trail, producing a noticeable meteor shower.
Astronomers are studying the Spitzer image for clues to the comet's
composition and how it fell apart. Like NASA's Deep Impact experiment, in
which a probe smashed into comet Tempel 1, the cracked Comet
73P/Schwassman-Wachmann 3 provides a perfect laboratory for studying the
pristine interior of a comet.
This image was taken from May 4 to May 6 by Spitzer's multi-band imaging
photometer, using its 24-micron wavelength channel.
