[meteorite-list] Annefrank Flyby A Success
From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Thu Apr 22 10:06:13 2004
Annefrank flyby a success
by Andrew Sengul
University of Washington Daily Online
November 4, 2002
A group of scientists, including UW astronomy professor Donald Brownlee,
spent last Friday and Saturday at the NASA Jet Propulsion Laboratory in
Pasadena, Calif., to coordinate an outer-space mission more than seven years
in planning. At a critical moment around 8:50 p.m. on Friday afternoon, the
Stardust spacecraft passed within 3,000 kilometers of an asteroid called
5535 Annefrank, sending photographs and other data back to Earth.
"It was a huge success," said Brownlee, the mission's chief scientist.
"Everything worked just great. We got tremendous pictures, better than what
we expected. When the spacecraft first came in, we were a little worried,
since we couldn't distinguish the asteroid from the stars, but once we got
closer, we could see it very clearly. It turned out that we were approaching
the asteroid's night side, and since all asteroids are different shapes, you
can't definitively say which side will be light and which side will be dark.
The pictures we got show that the Annefrank asteroid is a lot bigger and a
lot darker than we originally expected. It's about [seven] kilometers in
diameter, the same size as the asteroid that killed off the dinosaurs 64
million years ago."
While the Annefrank flyby excited scientists involved, this weekend's
operation only constituted a dress rehearsal of sorts for the Stardust
spacecraft's upcoming encounter with the comet Wild 2 (pronounced vild two).
On Jan. 2, 2004, the spacecraft will pass within 75 miles of this new comet,
close enough to capture some of the gas and dust surrounding its nucleus.
Traveling at about 13,400 mph, the spacecraft will capture particles
traveling many times the speed of sound.
"Basically, we got to see how all of Stardust's systems worked with this
encounter," said Brownlee. "With the asteroid flyby, we passed a major
milestone in the mission. After this, all Stardust has left to do is collect
the samples from Wild 2 and return to Earth."
Planning for the Stardust began in 1995, and the program was approved and
funded by NASA a year later, costing $200 million - a remarkably low price
for a space mission. Its main goal is to gather samples of dust from outer
space, hence its name. Wild 2 was chosen for sampling because it is the
easiest and most economical comet to reach from Earth.
"Comets are like ancient records of the history of our solar system,"
Brownlee said. "Most of them are in orbits far beyond our reach, and Wild 2
has only been in its current orbit since 1974. Its orbit used to span
between Jupiter's and Neptune's, but in 1974 it passed so near to Jupiter
that the planet's gravity altered its course, and now it orbits between
Jupiter and Mars."
The asteroid takes its name from Anne Frank, a Jewish teenager who recorded
her experiences hiding from the Nazis in Amsterdam during World War II in a
now-famous diary. It was discovered in 1942 by the German astronomer Karl
Reinmuth, three months before the Frank family first went into hiding, but
its current name was not given until long after the war ended.
Following its encounter with Wild 2, Stardust will return to Earth and
deposit its samples in a self-return capsule that will parachute to the
ground in Utah around Jan. 15, 2006. The Stardust project is the first
sample-return space mission in the United States since the last Apollo moon
landing in 1974.
"It's really exciting to have done this successfully," said Brownlee. "Doing
things like this in space takes a lot of talented people working very hard.
There's a lot that can go wrong in space, so when everything works out like
this, it's wonderful."
More information about the mission, along with an official press release
containing pictures of the asteroid, is available at
Received on Mon 04 Nov 2002 10:25:34 PM PST