Updated at 4:35 p.m. ET.
Some observers were treated to a light show last night when
the Department of Defense destroyed a falling spy satellite.
"I'm still having a hard time believing I actually
caught the debris, but two others with us also saw a bright dot move fast from
what was to be the intercept position," Hawaii-based skywatcher Rob
Ratkowski told SPACE.com.
He observed a meteor shower of sorts when, apparently, bits
of debris from the broken-up
satellite burned up as they fell through Earth's atmosphere. Ratkowski, a
professional photographer and astronomy enthusiast, took photos of what he saw
from Maui, near where the U.S. Navy ship fired the missile that
intercepted the satellite.
Examining the evidence
"It wasn't until I got home and examined the images
that I started seeing more dots in the field of view," he said.
His photos were posted to the amateur satellite observer's
mailing list, SeeSat-L.
By enhancing the contrast of one
image an observer commenting on the mailing list counted 552
"dots" in it, presumably each representing a bit of satellite
material.
While the images have not been confirmed as actually
depicting debris from the satellite, as opposed to stars or other objects, some
posters to the site vouched for their likely authenticity.
"I've taken a lot of astrophotos and I don't think even
the brightest stars would register in so short an exposure (1/500 second) with
so small a telescope," Patrick Wiggins wrote.
Ratkowski also took an image of what he believes to be the vapor
trail of hydrazine gas created when the satellite's liquid fuel spewed into
the vacuum of space. But this image was debated on the site.
"I can't imagine the vapour trail as a long line — it
should be a cloud/'comet'?" wrote B. Gimle.
The satellite was intercepted
by a Navy missile launched at 10:26 p.m. ET last night. Military officials said
they think the missile successfully hit
the failing satellite, with a high probability that it struck the fuel
tank full of hydrazine, a chemical that would have been dangerous had it landed
on Earth. The debris from the broken-up bus-sized satellite is probably too small
to be hazardous to humans, said a senior
military officer.
Other views
As the night went on the debris followed the ground path of
the satellite's orbit and fell over the northwestern United States and Canada,
giving observers there a show.
"At approx. 19:43 PDT ... a group of about 30 people, PG
Centre members and public, witnessed what we assume was the demise of the spy
satellite USA 193," wrote Brian Battersby of the Prince George Centre of
the Royal Astronomical Society of Canada, in a message posted to SeeSat-L.
"Many debris trails were witnessed moving from
south-west to north-east at high altitude," Battersby wrote. "One was
especially bright and long lasting. I can recall about 6 bright trails and 15
fainter ones. The debris trails seemed to come in "waves" with the
first wave being brighter than the debris that followed behind it. The trails
seemed to be in a fan shape with the trails being wider apart in the north-east
than they were in the south-east."
Second chances
Observers who missed last night's show may get another chance.
It's possible that viewers along the ground path of the satellite's remains may
be able to see debris as it falls through the atmosphere over the coming days,
said Geoff Chester, public affairs officer for the U.S. Naval Observatory in
Washington, D.C.
"Due to the relatively low
altitude of the satellite at the time of the engagement, debris will begin to
re-enter the earth's atmosphere immediately," said a Department of Defense
statement. "Nearly all of the debris will burn up on reentry within 24-48
hours and the remaining debris should re-enter within 40 days."
Marine General James Cartwright confirmed at a Pentagon news conference that debris from the satellite has been observed entering the atmosphere, but none has so far been seen to survive re-entry. He also said that a vapor cloud was spotted. He did not specify which observatories made these observations.
SPACE.com contacted a number of astronomical
observatories but none reported attempting to observe the satellite last night,
nor did they have plans for future observations of the debris.
"We didn't observe the satellite destruction last
night," said a spokesperson from the W. M. Keck Observatory in Mauna Kea,
Hawaii, who declined to be named. "Our telescope cannot track something
moving that fast. To track an object moving that fast you need a much more
nimble telescope."
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