WASHINGTON 8 Jan. - Bima Sakti mengandungi kira-kira 17 bilion planet yang mempunyai saiz seperti Bumi, sekali gus meningkatkan peluang untuk menemui planet kedua yang boleh didiami manusia, menurut kajian terbaharu yang didedahkan semalam.
Ahli astronomi yang menggunakan kapal angkasa lepas Kepler milik NASA, mendapati kira-kira 17 peratus bintang di galaksi mengandungi planet sebesar Bumi dengan tempoh orbit yang hampir sama. Bima Sakti mengandungi kira-kira 100 bilion bintang, bermakna kira-kira satu daripada setiap bintang tersebut mempunyai planet bersaiz Bumi yang mengelilinginya. Namun, penemuan itu tidak bermakna kesemua planet tersebut yang berada di luar atau di dalam sistem suria boleh didiami, tetapi ia tetap meningkatkan peluang penemuan planet sama seperti Bumi.
Untuk boleh didiami dan membolehkan air mengalir dalam bentuk cecair, sesebuah planet itu haruslah terletak pada jarak tertentu dari bintang yang diorbit supaya suhu tidak terlalu sejuk atau panas. Ahli astronomi membuat penemuan itu ketika kapal angka lepas Kepler melalui bahagian depan sistem suria planet-planet itu dan menyebabkan berlaku gerhana kecil yang memalapkan pancaran cahaya. Mereka mendapati 17 peratus dari bintang-bintang itu mempunyai planet yang bersaiz 0.8 hingga 1.25 kali hampir sama besar dengan Bumi dan tempoh orbit selama 85 hari atau kurang. Kira-kira satu perempat dari bintang itu pula memiliki saiz 1.25 hingga sekali ganda saiz Bumi dengan tempoh orbit selama 150 hari atau kurang, manakala satu planet yang mempunyai saiz dua atau empat kali lebih besar dari Bumi mengorbit selama 250 hari. Penyelidik itu membentangkan analisis mereka pada mesyuarat American Astronomical Society di Long Beach, California. - AFP |
harimau76 posted on 9-1-2013 08:13 AM
interesting... but then nak sampai ker situ musti akan amik beribu tahun cahaya...
the_killer posted on 9-1-2013 08:15 AM
tau takpa..kita harapkan US ja..untuk menjelajah angkasa walau kita dok kata anti US ka apa ka:lol ...
NASA’s Kepler mission, whose goal is to find Earth-like planets orbiting other stars, has found 461 new potential planets, NASAannounced Monday. The data were collected by Kepler between May 2009 and 2011, and more observations are needed to confirm the findings.
Christopher Burke, from the SETI Institute in Mountain View, Calif., was the lead scientist in charge of analyzing the data collected by Kepler’s telescope and said of the discovery, “There is no better way to kick off the start of the Kepler extended mission than to discover more possible outposts on the frontier of potentially life-bearing worlds.”
In order to discover potential planets, Kepler’s telescope analyzes the changes of brightness of a host star. Objects, such as planets or debris, will pass in front of the host star, changing its brightness as seen from Earth. This is called a transit, and three such transits have to be observed before the object is classified as a potential planet.
Once an object is classified as a potential planet, scientists conduct further observations to make sure. Including this recent discovery, NASA’s Kepler mission has discovered 2,740 potential planets that orbit 2,036 stars. Of all the potential planets, 1,290 are roughly the size of Neptune, 816 are “Super-Earth” size, roughly 1.25 to 2 times the diameter of Earth, 351 are roughly the size of Earth, 202 are similar in size to Jupiter and 81 are even larger than that. Smaller planets are harder to see, of course.
What is exciting NASA about the latest discovery is all the potential planets that are similar to or smaller than Earth as well as the number of host stars with multiple potential planets.
Jack Lissauer, a planetary scientist from NASA'sAmes Research Center in Moffett Field, Calif., said, “The large number of multi-candidate systems being found by Kepler implies that a substantial fraction of exoplanets reside in flat multi-planet systems.” According to Lissauer, potential Earth-like planets are being discovered in systems much like our own, with several planets orbiting a host star.
Of the 461 planets found, four could potentially have liquid water as they orbit their host star in the “Goldilocks zone,” where conditions are "just right."
According to Steve Howell, a Kepler mission project scientist at Ames Research Center, finding a truly Earth-like planet is a real possibility. Howell says, “The analysis of increasingly longer time periods of Kepler data uncovers smaller planets in longer period orbits, orbital periods similar to Earth's. It is no longer a question of will we find a true Earth analogue, but a question of when.”
http://www.ibtimes.com/461-new-planets-found-another-earth-just-question-when-999074NIXAR posted on 9-1-2013 10:29 AM
yg tu dh jumpa aritu. penuh dgn berlian. moga x dak sapa2 sampaikan berita
NIXAR posted on 9-1-2013 10:29 AM
yg tu dh jumpa aritu. penuh dgn berlian. moga x dak sapa2 sampaikan berita
dino posted on 9-1-2013 10:32 AM
tu la hrp2 takde sapa bagitau.... bkn tak kenal.... ahkak tu sanggup buat ape saja
NIXAR posted on 9-1-2013 10:35 AM
jika utk menjelajah dunia baru ak x kisah. ak nak sokong beliau. boleh?
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