Oct. 12, 2012
Courtesy of the EuÂroÂpeÂan Space AgenÂcy and
A deÂterÂmined amÂaÂteur asÂtronÂoÂmer has reÂdisÂcovÂered a poÂtenÂtially hazÂardÂous asÂterÂoid that the exÂperts had lost track of, sciÂenÂtists have anÂnounced.
The GerÂman hobÂbyÂist, ErÂwin Schwab, made the find usÂing EuÂroÂpeÂan Space AgenÂcy facilÂiÂties and asÂsisÂtance, through a proÂgram that makes a ground telÂeÂscope availÂaÂble for amÂaÂteur use to help track asÂterÂoids.
The calÂcuÂlatÂed orÂbit of asÂterÂoid2008SE85, which takes about two years to cirÂcle the Sun. The next close apÂproach to our planÂet will be on March 29, to withÂin a safe disÂtance of about 15 milÂlion km, or about a tenth of the disÂtance to the Sun. A much closÂer pasÂsage is preÂdicted for 2098, when the asÂterÂoid will fly by at about 6 milÂlion km. This is twice the disÂtance it was preÂdicted to have beÂfore its re-discovery. (CredÂits: ESA/DeiÂmos)
New proÂjecÂtions inÂdiÂcate the half-kiÂloÂmeÂter (1/3-mile) wide obÂject wonâ€™t threatÂen Earth anÂyÂtime soon.
Schwab conÂducted his asÂterÂoid hunt in SepÂtemÂber durÂing an obÂservaÂtÂion slot at agenÂcyâ€™s OpÂtiÂcal Ground StaÂtÂion in TenÂerÂife, Spain, sponÂsored by the AgenÂcyâ€™s Space SituaÂtÂional AwareÂness proÂgram. He was out to reÂdisÂcovÂer the obÂject, known by its catÂaÂlogue name as 2008SE85.
The space rock was disÂcovÂered in Sept. 2008 by the Catalina Sky SurÂvey, and seen by a few obÂservatories inÂto the next month. But no one had obÂserved it since then and preÂdicÂtions for its curÂrent poÂsiÂtion had beÂcome so inÂacÂcuÂrate that the obÂject was conÂsidÂered lost.
UsÂing the 1-meter telÂeÂscope, Schwab looked for the obÂject withÂin the â€œarea of unÂcerÂtainÂtyâ€ of its preÂdicted poÂsiÂtion, acÂcordÂing to agenÂcy sciÂenÂtists. AfÂter only a few hours, he found it about 2 deÂgrees away from its preÂdicted poÂsiÂtion. Thatâ€™s about four moon widths as seen from Earth.
â€œI found the obÂject on the eveÂning of SatÂurÂday,â€ Sept. 15, Schwab said. â€œI then saw it again at 1:30 on SunÂday mornÂing â€“ and that was my birthÂday! It was one of the nicÂest birthÂday preÂsents.â€
The findÂings will alÂlow a much more acÂcuÂrate deÂterÂminaÂtÂion of its orÂbit and help conÂfirm that it wonâ€™t threatÂen Earth anÂyÂtime soon, reÂsearchÂers said. â€œPoÂtenÂtially HazÂardÂous AsÂterÂoidsâ€ are deÂfined as those that apÂproach Earth closÂer than about 7 milÂlion km (aÂbout 4.4 milÂlion miles), acÂcordÂing to the agenÂcy; about 1,300 such obÂjects are known.