Lost, potentially hazardous asteroid rediscovered

Oct 15, 2012
Lost asteroid rediscovered with a little help from ESA
Animation of asteroid 2008SE85, moving between the stars. The images were tracked on the asteroid, thus the stars appear as small trails. Credit: ESA/E. Schwab

(Phys.org)—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 , and observed by a few observatories to October 2008.   

The asteroid takes about two years to circle the Sun. The next close approach to our planet will be on 29 March 2013, to within a safe distance of about 15 million km, or about a tenth of the distance to the Sun. A much closer passage is predicted for 2098, when the asteroid will fly by at about 6 million km. This is twice the distance it was predicted to have before its re-discovery. Credit: ESA/Deimos

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'.

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 and help confirm that it will not be a threat to Earth anytime soon.

OGS telescope. Credit: ESA

Potentially Hazardous Asteroids approach Earth closer than about 7 million km; about 1300 are 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 Center, which acknowledged the rediscovery of 2008SE85 by releasing a Minor Planet Electronic Circular announcing the new observations.

"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 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 Survey started by Matthias Busch from Heppenheim, Germany, discovered two new near-Earth objects during the last year while working with our observing programme."

Explore further: Curiosity brushes 'Bonanza king' target anticipating fourth red planet rock drilling

Related Stories

Amateur skywatchers help space hazards team

Oct 13, 2011

For the first time, observations coordinated by ESA's space hazards team have found an asteroid that comes close enough to Earth to pose an impact threat. The space rock was found by amateur astronomers, highlighting ...

Asteroid to Make Rare Close Flyby of Earth

Jan 24, 2008

Scientists are monitoring the orbit of asteroid 2007 TU24. The asteroid, believed to be between 150 meters (500 feet) and 610 meters (2,000 feet) in size, is expected to fly past Earth on Jan. 29, with its ...

Near-miss asteroid will return next year

Mar 16, 2012

(PhysOrg.com) -- When it whizzes past Earth in 2013, a newly discovered asteroid is going to miss our planet – but not by much. The 50 m space rock is expected to come closer than many satellites, highlighting ...

Amateur astronomers boost ESA's asteroid hunt

May 15, 2012

A partnership with the UK’s Faulkes Telescope Project promises to boost the Agency’s space hazards research while helping students to discover potentially dangerous space rocks.

Recommended for you

Electric sparks may alter evolution of lunar soil

44 minutes ago

The moon appears to be a tranquil place, but modeling done by University of New Hampshire and NASA scientists suggests that, over the eons, periodic storms of solar energetic particles may have significantly ...

Why NASA studies the ultraviolet sun

2 hours ago

(Phys.org) —You cannot look at the sun without special filters, and the naked eye cannot perceive certain wavelengths of sunlight. Solar physicists must consequently rely on spacecraft that can observe ...

Two dynamos drive Jupiter's magnetic field

3 hours ago

(Phys.org) —Superlatives are the trademark of the planet Jupiter. The magnetic field at the top edge of the cloud surrounding the largest member of the solar system is around ten times stronger than Earth's, ...

User comments : 5

Adjust slider to filter visible comments by rank

Display comments: newest first

JGHunter
2 / 5 (2) Oct 15, 2012
"hazerdous"? What is this hazerdous?
JustChris
not rated yet Oct 15, 2012
Crossing Earth's orbit could qualify it as potentially hazardous.
mountain_team_guy
1 / 5 (4) Oct 15, 2012
I don't reed too gud no how. ..
jscroft
1 / 5 (5) Oct 15, 2012
u gys r meen
Blakut
not rated yet Oct 15, 2012
That asteroid basterd! It is definately very hazerdous!