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美国宇航局地图93%的近地小行星其他恐龙希望他们科学新闻

发布时间:2018/09/12  编辑:admin

Armageddon can wait, NASA‘;s in charge for a little while longer。 The space agency recently released to the general public a report which censuses more than 93% of the total number of asteroids in the vicinity of Earth’;s orbit, meaning they’;re all tagged and tracked –; risk of undetected collision to a minimum。 That’;s not all either, it seems the number of near-Earth asteroids is a lot smaller than previously thought。

The data on the astereoids was gathered by NASA’;s Wide-field Infared Survey Explorer (WISE), a satellite which had completed its mission with all instruments intact and quite a bit of fuel。 Instead of scrapping it, the probe was put to extremely good use and repurposed for the mission of tracking down every space rock, big or small, in the vicinity of Earth’;s orbit around the sun。

The study, re-named NEOWISE, studies space rocks for two years, time in which it surveyed over 100 thousand objects in the prime location between Mars and Jupiter alone  — the so-called Jupiter Belt。 NASA informs that NEOWISE has found far fewer celestial bodies in the vecinity of Earth’;s bodies than previous Earth observations had led scientists to believe。 As such, the probe logged 19,500 mid-sized (between 300 and 3,300 feet wide) near-Earth asteroids instead of the previous estimate of 35,000。

Near-Earth asteroid census。 Click for larger view。 (c) NASA

Near-Earth asteroid census。 Click for larger view。 (c) NASA

Regarding larger, apocalyptic asteroids (more than 6 miles in diameter, the kind that killed off the dinosaurs)  the probe mapped tracked down 981, fewer than the initial 1000 estimated, of which 911 have been mapped in the sky。 In all, 93% of the near-Earth asteroids have been now mapped。

本文源自: 环亚娱乐



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