Lost Asteroid Rediscovered By Amateur Astronomer
October 13, 2012

Lost And Found – Amateur Astronomer Rediscovers Potentially Hazardous Asteroid

Lee Rannals for redOrbit.com - Your Universe Online

The European Space Agency (ESA) reports that it has rediscovered an asteroid that was once lost through the agency's space hazards program.

Potentially Hazardous Asteroid 2008SE85 was first discovered back in September 2008 by the Catalina Sky Survey, and was observed by a few observatories the following month.

However, no one since then has observed the object, and predictions for its current position had become so inaccurate that the asteroid was considered lost.

Amateur astronomer Erwin Schwab, from Germany stepped in while performing an asteroid hunt in September during a regular observation slot of ESA's Optical Ground Station in Tenerife, Spain.

During his time at the station, he was determined to try and rediscover the asteroid 2008SE85.

He planned his observing sequence to look for the object within the area of uncertainty of its predicted position. After just a few hours, he was able to find it at about 2 degrees away from its predicted position, which is about four times the apparent size of the Moon.

“I found the object on the evening of Saturday, 15 September, while checking the images on my computer,” Erwin said.

“I then saw it again at 01:30 on Sunday morning — and that was my birthday! It was one of the nicest birthday presents.”

The new observations of the large asteroid will allow for more accurate determination of its orbit, and help to confirm that it will not be a threat to Earth anytime soon.

To be considered a Potentially Hazardous Asteroid, it must approach at least 4.3 million miles to Earth.

Once a new asteroid is discovered, follow-up observations must be done within a few hours and then days to ensure it is not lost.

After the rediscovery of 2008SE85, asteroid position measurements were collected from observers around the world.

“These observations were part of the strong collaboration that we have with a number of experienced backyard observers,” said Detlef Koschny, Head of the Near-Earth Object segment of ESA´s Space Situational Awareness program.

"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 program."

Animation of asteroid 2008SE85, moving between the stars. The images were tracked on the asteroid, thus the stars appear as small trails. Credits: ESA/E. Schwab