英語聽力文摘 類地行星發(fā)現(xiàn)者

00:00

00:00

MP3下載

https://online2.tingclass.net/lesson/shi0529/0007/7643/275.mp3

https://image.tingclass.net/statics/js/2012

瑞士科學家米歇爾·梅耶帶領歐洲科學家小組宣布發(fā)現(xiàn)了一顆新的可能適宜人類居住的星球，現(xiàn)在，他又制定了更大的目標：尋找地外生命的跡象。該發(fā)現(xiàn)小組的成員斯蒂凡·尤迪推測這顆新星表面可能富含液態(tài)水，但他指出，他的這種推測是以行星的形成方式為基礎，而不是以任何的證據(jù)。梅耶認為還會發(fā)現(xiàn)許多被科學家認為可能適合人類居住的星球。但短期內，最重要的發(fā)現(xiàn)還是這顆與地球相似的低質量行星581c。581c大約是地球質量的5倍。但它仍然是至今太陽系外發(fā)現(xiàn)的最小的一顆行星。梅耶認為美國宇航局的“類地行星發(fā)現(xiàn)者”號和歐洲航天局的“達爾文”探測衛(wèi)星將在尋找地外智慧生命上做出重要的貢獻。

For a planet to support life, the planet must be located within its star’s habitable zone. That is, it must be located at a distance where the temperature would allow water to remain in liquid form.

At present we’ve identified about 250 extrasolar planets, and only two have appeared to be located close to or within this zone. And most of these extrasolar planets are about the size of Jupiter, not Earth. So, is Earth’s size and orbit unique? Unlikely. The problem is that planets the approximate mass and orbit distance of Earth are too difficult to detect using our current space technology.

However, telescopes in the works right now are being designed specifically to overcome the obstacles astronomers face detecting Earth-like planets. One such project is NASA’s Terrestrial Planet Finder, or TPF. TPF’s capabilities will include blocking out the glare of stars, making visible relatively tiny Earth-like planets orbiting them.

TPF will be able to search the habitable zones of stars located up to fifty light years away, analyzing the composition of planets’ atmospheres. It will look for gasses that signal the possibility of life, gasses such as oxygen, water vapor, methane, and carbon dioxide. And TPF will be capable of taking pictures that are one-hundred times more detailed than the photographs of the Hubble Space Telescope(哈勃太空望遠鏡).

Many astronomers are hopeful that these new telescopes will lead to a groundbreaking discovery of life elsewhere in the universe. Regardless of what discoveries they may yield, TPF and other space telescopes in development promise to bring exciting changes to space exploration.