Lost
asteroid rediscovered with a little help from ESA
A
potentially hazardous asteroid once found but then lost has been rediscovered
and its orbit confirmed by a determined amateur astronomer working with ESA’s
space hazards programme. The half-kilometre object will not threaten Earth
anytime soon.
Amateur
astronomer Erwin Schwab, from Germany, conducted his asteroid hunt in September
during a regular observation slot at ESA’s Optical Ground Station in Tenerife,
Spain, sponsored by the Agency’s Space Situational Awareness
programme.
He
was determined to rediscover the object, known by its catalogue name as
2008SE85.Potentially Hazardous Asteroid 2008SE85 was discovered in September
2008 by the Catalina Sky Survey, and observed by a few observatories to October
2008.
Asteroid
considered lost
Since
then, however, nobody had observed the object and predictions for its current
position had become so inaccurate that the object was considered to be
‘lost’.
Orbit
of 2008SE85
Erwin
planned his observing sequence to look for the object within the area of
uncertainty of its predicted position. After only a few hours, he found it about
2° – four times the apparent size of the Moon – away from its predicted
position.“I found the object on the evening of Saturday, 15 September, while
checking the images on my computer,” says Erwin.
“I
then saw it again at 01:30 on Sunday morning – and that was my birthday! It was
one of the nicest birthday presents.” These new observations of the roughly 500
m-diameter asteroid will allow a much more accurate determination of its orbit
and help confirm that it will not be a threat to Earth anytime
soon.
Potentially
Hazardous Asteroids approach Earth closer than about 7 million km; about 1300 is
known. When a new asteroid is discovered, follow-up observations must be done
within a few hours and then days to ensure it is not subsequently lost.
USA-based
Minor Planet Center acknowledges the find Asteroid position measurements are
collected from observers worldwide by the US-based Minor Planet Center, which
acknowledged the rediscovery of 2008SE85 by releasing a Minor Planet Electronic
Circular announcing the new observations.
1m
telescope at ESA's Optical Ground Station
“These
observations were part of the strong collaboration that we have with a number of
experienced backyard observers,” says Detlef Koschny, Head of the Near-Earth
Object segment of ESA’s Space Situational Awareness programme.
"It’s
not the first time our collaboration with amateurs has scored such a success.
Members of the Teide Observatory Tenerife Asteroid Survey started by Matthias
Busch from Heppenheim, Germany, discovered two new near-Earth objects during the
last year while working with our observing programme."
For
further information visit: http://www.esa.int/esaCP/
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