{"id":4407,"date":"2016-01-15T15:38:25","date_gmt":"2016-01-15T13:38:25","guid":{"rendered":"http:\/\/bilimvegelecek.com.tr\/?p=4407"},"modified":"2016-01-15T15:38:25","modified_gmt":"2016-01-15T13:38:25","slug":"dev-kuyrukluyildizlar-dunyadaki-yasami-tehdit-edebilir","status":"publish","type":"post","link":"https:\/\/bilimvegelecek.com.tr\/index.php\/2016\/01\/15\/dev-kuyrukluyildizlar-dunyadaki-yasami-tehdit-edebilir","title":{"rendered":"Dev kuyrukluy\u0131ld\u0131zlar d\u00fcnyadaki ya\u015fam\u0131 tehdit edebilir"},"content":{"rendered":"

G\u00f6rsel a\u00e7\u0131klamas\u0131:<\/strong> D\u00fcnya\u2019dan \u00e7ok uzakta olduklar\u0131 i\u00e7in, en b\u00fcy\u00fck teleskoplarla dahi bak\u0131ld\u0131\u011f\u0131nda \u201ccentaur\u201dlar (kuyrukluy\u0131ld\u0131zlar) nokta kadar bir par\u0131lt\u0131 \u015feklinde g\u00f6r\u00fcl\u00fcr. Foto\u011fraftan hareketle, Sat\u00fcrn\u2019\u00fcn 200 km \u00e7ap\u0131ndaki uydusu Phoebe ge\u00e7mi\u015fte gezegenin yer\u00e7ekimine yakalanan bir kuyrukluy\u0131ld\u0131z olabilir. Uzay ara\u00e7lar\u0131 di\u011fer kuyrukluy\u0131ld\u0131zlar\u0131 ziyaret etmek \u00fczere g\u00f6nderilmeye ba\u015flanana kadar, onlar\u0131n nas\u0131l g\u00f6r\u00fcnd\u00fcklerine dair fikrimiz Sat\u00fcrn\u2019\u00fcn y\u00f6r\u00fcngesindeki Cassini insans\u0131z uzay arac\u0131 ile elde edilen bu foto\u011frafla s\u0131n\u0131rl\u0131 kalacak. Kaynak: NASA\/JPL-Caltech\/Space Science Institute.<\/p>\n

 <\/p>\n

Armagh G\u00f6zlemevi ve Buckingham \u00dcniversitesi\u2019nden bir grup g\u00f6kbilimcinin bildirdi\u011fine g\u00f6re, ge\u00e7ti\u011fimiz 20 y\u0131lda gezegen sisteminin d\u0131\u015f\u0131nda y\u00fczlerce devasa kuyrukluy\u0131ld\u0131z ke\u015ffedildi ve bu nesneler yery\u00fcz\u00fcndeki ya\u015fam\u0131 di\u011fer k\u00fc\u00e7\u00fck gezegenlerden (asteroidler) daha fazla tehdit ediyor. Buckingham \u00dcniversitesi profes\u00f6rleri Bill Napier ve Duncan Steel, Armagh G\u00f6zlemevi\u2019nden Prof. Mark Bailey ve Dr. David Asher g\u00fcncel ara\u015ft\u0131rmalar\u0131n\u0131n derlemesini Kraliyet Astronomi Derne\u011fi\u2019nin yay\u0131n\u0131 olan Astronomy and Geophysics<\/em>\u2019in Aral\u0131k say\u0131s\u0131nda yay\u0131mlad\u0131lar.<\/p>\n

\u201cCentaurs\u201d olarak adland\u0131r\u0131lan dev kuyrukluy\u0131ld\u0131zlar J\u00fcpiter, Sat\u00fcrn, Uran\u00fcs ve Nept\u00fcn gibi devasa d\u0131\u015f gezegenlerin y\u00f6r\u00fcngelerinden ge\u00e7erek de\u011fi\u015fken y\u00f6r\u00fcngelerde hareket ediyor. Kimi zaman, gezegenlere ait yer\u00e7ekimi sahalar\u0131 bu nesnelerin D\u00fcnya\u2019n\u0131n y\u00f6r\u00fcngesine do\u011fru sapmas\u0131na sebep olabiliyor.<\/p>\n

Dev kuyrukluy\u0131ld\u0131zlar genellikle 50 ila 100 km \u00e7ap\u0131nda ya da daha b\u00fcy\u00fck olurlar ve tek ba\u015f\u0131na b\u00f6yle bir g\u00f6vde, d\u00fcnyan\u0131n y\u00f6r\u00fcngesinden ge\u00e7en asteroidlerin t\u00fcm\u00fcnden daha fazla k\u00fctle i\u00e7erir. \u0130\u00e7 G\u00fcne\u015f Sistemi\u2019ne giren dev kuyrukluy\u0131ld\u0131zlar\u0131n oranlar\u0131na dair hesaplar g\u00f6steriyor ki, her 40.000-100.000 y\u0131lda bir \u0130\u00e7 G\u00fcne\u015f Sistemi\u2019ne giren bir kuyrukluy\u0131ld\u0131z, d\u00fcnyan\u0131n y\u00f6r\u00fcngesinden ge\u00e7en yola do\u011fru sapma ya\u015far. Bu s\u00fcre i\u00e7inde de yak\u0131n uzayda toz ve daha b\u00fcy\u00fck par\u00e7alara ayr\u0131lan kuyrukluy\u0131ld\u0131za ait par\u00e7alar\u0131n \u0130\u00e7 G\u00fcne\u015f Sistemi\u2019ne ta\u015fmas\u0131 beklenir ve bunun gezegenimiz \u00fczerinde ka\u00e7\u0131n\u0131lmaz etkileri vard\u0131r.<\/p>\n

Karasal d\u00fczlemde ya\u015fand\u0131\u011f\u0131 bilinen \u015fiddetli y\u0131k\u0131mlar ve antik medeniyetlerin ilerleyi\u015finde meydana gelen kesintiler bizim yak\u0131n uzaydaki bilgi birikimimizle birle\u015fti\u011finde; b\u00f6yle bir kuyrukluy\u0131ld\u0131z\u0131n geli\u015finin 30.000 y\u0131l \u00f6nce ya\u015fand\u0131\u011f\u0131 \u00e7\u0131kar\u0131m\u0131n\u0131 yap\u0131labilir. Bu devasa kuyrukluy\u0131ld\u0131z, boyutlar\u0131 toz zerreci\u011fi ile kilometrelerce geni\u015flikteki y\u00fczeyler aras\u0131nda de\u011fi\u015fen kal\u0131nt\u0131lar\u0131 \u0130\u00e7 G\u00fcne\u015f Sistemi\u2019ne yaym\u0131\u015f olabilir.<\/p>\n

Yerbilimciler ve fosilbilimciler taraf\u0131ndan tan\u0131mlanan, M\u00d6 10.800 ve 2300 dolaylar\u0131nda ya\u015fanan belirli \u00e7evresel de\u011fi\u015fim a\u015famalar\u0131, bu yeni kuyrukluy\u0131ld\u0131z pop\u00fclasyonu anlay\u0131\u015f\u0131yla tutarl\u0131l\u0131k g\u00f6steriyor. Uzak ge\u00e7mi\u015fteki b\u00fcy\u00fck \u00e7apl\u0131 kitlesel yok olu\u015flar\u0131n baz\u0131lar\u0131, mesela dinozorlar\u0131n soylar\u0131n\u0131n 65 milyon y\u0131l \u00f6nce t\u00fckenmesi bu dev kuyrukluy\u0131ld\u0131z hipoteziyle ili\u015fkilendirilebilir.<\/p>\n

Prof. Napier\u2019in duruma y\u00f6nelik yorumu \u015fu \u015fekilde: \u201cGe\u00e7ti\u011fimiz 30 y\u0131lda bir asteroidin D\u00fcnya\u2019ya \u00e7arpma riskini takip ve analiz etmek i\u00e7in \u00e7ok \u00e7aba sarf ettik. \u00c7al\u0131\u015fmam\u0131z yak\u0131n \u00e7evrenin \u00f6tesine bakmay\u0131 ve kuyrukluy\u0131ld\u0131zlar\u0131 saptamak i\u00e7in J\u00fcpiter\u2019in y\u00f6r\u00fcngesinin de \u00f6tesini g\u00f6zlemlemeyi gerektiriyor. E\u011fer hakl\u0131ysak, bu uzak mesafedeki kuyrukluy\u0131ld\u0131zlar d\u00fcnya i\u00e7in ciddi bir tehlike olabilir. \u015eimdi onlar\u0131 daha iyi anlaman\u0131n zaman\u0131.\u201d<\/p>\n

Ayr\u0131ca grup, farkl\u0131 bilim dallar\u0131ndan da kendi \u00e7al\u0131\u015fmalar\u0131n\u0131 destekler nitelikte bulgular meydana \u00e7\u0131kard\u0131. Mesela Apollo program\u0131yla Ay\u2019\u0131n y\u00fczeyinden al\u0131nan ta\u015flara bak\u0131larak yap\u0131lan tan\u0131mlamalara g\u00f6re 1 milimetreden k\u00fc\u00e7\u00fck olan kraterlerin neredeyse hepsi 30.000 y\u0131ldan daha gen\u00e7 ki, bu da o zamandan beri s\u00fcregelen \u0130\u00e7 G\u00fcne\u015f Sistemi\u2019ndeki toz oran\u0131n\u0131n art\u0131\u015f\u0131na i\u015faret ediyor.<\/p>\n

\u00c7eviren: \u0130layda \u00d6nc\u00fc<\/strong><\/p>\n

 <\/p>\n

Kaynak:<\/strong> http:\/\/www.sciencedaily.com\/releases\/2015\/12\/151222082339.htm<\/a><\/p>\n

 <\/p>\n

 <\/p>\n","protected":false},"excerpt":{"rendered":"

G\u00f6rsel a\u00e7\u0131klamas\u0131: D\u00fcnya\u2019dan \u00e7ok uzakta olduklar\u0131 i\u00e7in, en b\u00fcy\u00fck teleskoplarla dahi bak\u0131ld\u0131\u011f\u0131nda \u201ccentaur\u201dlar (kuyrukluy\u0131ld\u0131zlar) nokta kadar bir par\u0131lt\u0131 \u015feklinde g\u00f6r\u00fcl\u00fcr. Foto\u011fraftan hareketle, Sat\u00fcrn\u2019\u00fcn 200 km \u00e7ap\u0131ndaki uydusu Phoebe ge\u00e7mi\u015fte gezegenin yer\u00e7ekimine yakalanan bir kuyrukluy\u0131ld\u0131z olabilir. Uzay ara\u00e7lar\u0131 di\u011fer kuyrukluy\u0131ld\u0131zlar\u0131 ziyaret etmek \u00fczere g\u00f6nderilmeye ba\u015flanana kadar, onlar\u0131n nas\u0131l g\u00f6r\u00fcnd\u00fcklerine dair fikrimiz Sat\u00fcrn\u2019\u00fcn y\u00f6r\u00fcngesindeki Cassini insans\u0131z uzay […]<\/p>\n","protected":false},"author":1,"featured_media":4408,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[30,19],"tags":[],"class_list":["post-4407","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-astronomi","category-bilim-gundemi"],"acf":[],"aioseo_notices":[],"aioseo_head":"\n\t\t\n\t\n\t\n\t\n\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t