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February 28, 2000: In February 1999, NASA's
STARDUST spacecraft blasted off from the Kennedy Space Center for a daring
encounter with periodic comet Wild-2. Its ambitious goal is to intercept
Wild-2 in 2004, to capture tiny bits of comet dust and debris, and then
return them to Earth for analysis in 2006. On the way, STARDUST will also
sample a stream of dust
particles from outside the solar system.
"I'm Here! I'm OK!"
After one year in space STARDUST is doing well, say project officials.
The spacecraft has executed several flawless course adjustments, and last
week it deployed its aerogel
collector for a first-ever sampling of interstellar dust particles.
Still, STARDUST has given mission controllers their share of sleepless
STARDUST and its crew have successfully navigated three more safe mode events, all involving data handling by on-board software.
What's all the fuss about Wild-2?
Scientists are curious about comets because they are thought to be the
oldest, most primitive bodies in the solar system. Comets are made up of
the same stuff as the early Solar Nebula that collapsed to form the sun
and planets. It is now known that comets contain significant amounts of
water ice, dust, and carbon based compounds. They may have been an
important source of water and organic molecules for Earth when many comets
collided with our planet during a period of heavy bombardment over 4
billion years ago. Modern-day comets are like a time machine. They offer a
window into the past when the Solar System was young and life on Earth was
#1 It's fresh. Before its near miss with Jupiter in 1974 comet
Wild-2 was well-preserved in the frigid outer solar system. With its new
orbit, Wild-2 now comes much closer to the Sun. When a comet passes close
enough to the Sun, some of its material is boiled off into interplanetary
space. After about a thousand trips past the Sun, it loses most of its
volatile materials and no longer generates a coma or tail. Since Wild-2
has passed the Sun only a few times, it still has most of its dust and
gases - it is "pristine." By the time STARDUST encounters the comet,
Wild-2 will have made only five trips around the Sun. By contrast, Comet
Halley has passed the Sun more than 100 times.
Above: If comet Wild-2 had passed much closer to
Jupiter in 1974, it might have ended up like comet Shoemaker-Levy 9,
pictured above. Comet SL-9 was often referred to as the "string of pearls"
comet. It is famous for its suggestive appearance as well as its collision
with the planet Jupiter! The comet's original single nucleus was torn to
pieces by Jupiter's strong gravity during a close encounter with the solar
system's largest planet in 1992. The pieces are seen in this composite of
Hubble Space Telescope images to be "pearls" strung out along the comet's
orbital path. [more
|STARDUST Mission home
page -- from JPL
The Science of STARDUST -- from JPL
STARDUST Education web page -- from JPL
Why comet Wild-2? -- from the JPL STARDUST team
Where is comet Wild-2 right now? -- from the JPL STARDUST team, updated every 5 minutes
Orbital elements of comet Wild-2 -- from the JPL STARDUST team
More about aerogel -- from JPL
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