"Long before it's in the papers"
January 27, 2015


Amateur rediscovers lost asteroid

Oct. 12, 2012
Courtesy of the Eu­ro­pe­an Space Agen­cy
and World Science staff

A de­ter­mined am­a­teur as­tron­o­mer has re­dis­cov­ered a po­ten­tially haz­ard­ous as­ter­oid that the ex­perts had lost track of, sci­en­tists have an­nounced.

The Ger­man hob­by­ist, Er­win Schwab, made the find us­ing Eu­ro­pe­an Space Agen­cy facil­i­ties and as­sis­tance, through a pro­gram that makes a ground tel­e­scope avail­a­ble for am­a­teur use to help track as­ter­oids.

The cal­cu­lat­ed or­bit of as­ter­oid2008SE85, which takes about two years to cir­cle the Sun. The next close ap­proach to our plan­et will be on March 29, 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. (Cred­its: ESA/Dei­mos)

New pro­jec­tions in­di­cate the half-ki­lo­me­ter (1/3-mile) wide ob­ject won’t threat­en Earth an­y­time soon.

Schwab con­ducted his as­ter­oid hunt in Sep­tem­ber dur­ing an ob­serva­t­ion slot at agen­cy’s Op­ti­cal Ground Sta­t­ion in Ten­er­ife, Spain, spon­sored by the Agen­cy’s Space Situa­t­ional Aware­ness pro­gram. He was out to re­dis­cov­er the ob­ject, known by its cat­a­logue name as 2008SE85.

The space rock was dis­cov­ered in Sept. 2008 by the Catalina Sky Sur­vey, and seen by a few ob­servatories in­to the next month. But no one had ob­served it since then and pre­dic­tions for its cur­rent po­si­tion had be­come so in­ac­cu­rate that the ob­ject was con­sid­ered lost.

Us­ing the 1-meter tel­e­scope, Schwab looked for the ob­ject with­in the “area of un­cer­tain­ty” of its pre­dicted po­si­tion, ac­cord­ing to agen­cy sci­en­tists. Af­ter only a few hours, he found it about 2 de­grees away from its pre­dicted po­si­tion. That’s about four moon widths as seen from Earth.

“I found the ob­ject on the eve­ning of Sat­ur­day,” Sept. 15, Schwab said. “I then saw it again at 1:30 on Sun­day morn­ing – and that was my birth­day! It was one of the nic­est birth­day pre­sents.”

The find­ings will al­low a much more ac­cu­rate de­ter­mina­t­ion of its or­bit and help con­firm that it won’t threat­en Earth an­y­time soon, re­search­ers said. “Po­ten­tially Haz­ard­ous As­ter­oids” are de­fined as those that ap­proach Earth clos­er than about 7 mil­lion km (a­bout 4.4 mil­lion miles), ac­cord­ing to the agen­cy; about 1,300 such ob­jects are known.

When a new as­ter­oid is dis­cov­ered, fol­low-up ob­serva­t­ions must be done with­in a few hours and then days to pin­point its path enough to en­sure it’s not lost. 

As­ter­oid po­si­tion mea­sure­ments are col­lect­ed from ob­servers world­wide by the U.S.-based Mi­nor Plan­et Cen­ter, which ac­knowl­edged the re­dis­cov­ery of 2008SE85 by re­leas­ing a Mi­nor Plan­et Elec­tron­ic Cir­cu­lar an­nounc­ing the ob­serva­t­ions. They “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 the Eu­ro­pe­an agen­cy’s Space Situa­t­ional Aware­ness pro­gram.

“It’s not the first time our col­la­bora­t­ion with am­a­teurs has scored such a suc­cess,” he added. “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.”

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A determined amateur astronomer has rediscovered a potentially hazardous asteroid that the experts had lost track of, scientists have announced. The German hobbyist, Erwin Schwab, made the find using European Space Agency facilities and assistance, through a program that makes a ground telescope available for amateur use to help track asteroids. New projections indicate the half-kilometre (one-third mile) wide object won’t threaten Earth anytime soon. Schwab conducted his asteroid hunt in September during an observation slot at agency’s Optical Ground Station in Tenerife, Spain, sponsored by the Agency’s Space Situational Awareness program. He was out to rediscover the object, known by its catalogue name as 2008SE85. The space rock was discovered in September 2008 by the Catalina Sky Survey, and observed by a few observatories to October 2008. But no one had observed it since then and predictions for its current position had become so inaccurate that the object was considered lost. Using the 1-meter telescope, Erwin looked for the object within the “area of uncertainty” of its predicted position, according to agency scientists. After only a few hours, he found it about 2 degrees away from its predicted position. That’s about four moon widths as seen from Earth. “I found the object on the evening of Saturday,” Sept. 15, Schwab said. “I then saw it again at 1:30 on Sunday morning – and that was my birthday! It was one of the nicest birthday presents.” The findings will allow a much more accurate determination of its orbit and help confirm that it won’t threaten Earth anytime soon, researchers said. “Potentially Hazardous Asteroids” are defined as those that approach Earth closer than about 7 million km (about 4.4 million miles), according to the agency; about 1,300 such objects are known. When a new asteroid is discovered, follow-up observations must be done within a few hours and then days to pinpoint its path enough to ensure it’s not lost. Asteroid position measurements are collected from observers worldwide by the U.S.-based Minor Planet Center, which acknowledged the rediscovery of 2008SE85 by releasing a Minor Planet Electronic Circular announcing the observations. They “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 the European agency’s Space Situational Awareness programme. “It’s not the first time our collaboration with amateurs has scored such a success,” he added. 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.”