一颗小行星刚刚近距离划过地球，比月亮还近
<p><span word="With">With</span> <span word="all">all</span> <span word="the">the</span> <span word="large">large</span> <span word="asteroids">asteroids</span> <span word="hitting">hitting</span> <span word="the">the</span> <span word="news">news</span> <span word="lately">lately</span>, <span word="it">it</span> <span word="would">would</span> <span word="have">have</span> <span word="been">been</span> <span word="easy">easy</span> <span word="for">for</span> <span word="a">a</span> <span word="small">small</span> <span word="one">one</span> <span word="to">to</span> <span word="sneak">sneak</span> <span word="under">under</span> <span word="the">the</span> <span word="radar">radar</span>. <span word="In">In</span> <span word="fact">fact</span>, <span word="one">one</span> <span word="very">very</span> <span word="nearly">nearly</span> <span word="did">did</span>. <span word="On">On</span> <span word="April">April</span> 27, <span word="astronomers">astronomers</span> <span word="discovered">discovered</span> <span word="a">a</span> <span word="new">new</span> <span word="asteroid">asteroid</span>, <span word="a">a</span> <span word="little">little</span> <span word="pixie">pixie</span> <span word="of">of</span> <span word="a">a</span> <span word="space">space</span> <span word="rock">rock</span> <span word="between">between</span> 4 <span word="and">and</span> 8 <span word="metres">metres</span> (13 <span word="to">to</span> 26 <span word="feet">feet</span>) <span word="across">across</span>.</p><p>最近很多大型小行星登上资讯，小号的小行星就很容易从雷达下溜走。有一颗小行星就差点溜掉了。4月27日，天文学家发现了一颗新的小行星，是一小块太空岩石，直径在4到8米（13到26英尺）之间。</p><p><span word="It">It</span> <span word="was">was</span> <span word="already">already</span> <span word="close">close</span> <span word="to">to</span> <span word="Earth">Earth</span> <span word="at">at</span> <span word="this">this</span> <span word="point">point</span>, <span word="and">and</span> <span word="the">the</span> <span word="probability">probability</span> <span word="of">of</span> <span word="a">a</span> <span word="collision">collision</span> <span word="was">was</span> <span word="calculated">calculated</span> <span word="at">at</span> <span word="around">around</span> 10 <span word="percent">percent</span>. <span word="At">At</span> <span word="its">its</span> <span word="size">size</span>, <span word="it">it</span> <span word="would">would</span> <span word="have">have</span> <span word="burnt">burnt</span> <span word="up">up</span> <span word="on">on</span> <span word="atmospheric">atmospheric</span> <span word="entry">entry</span>, <span word="so">so</span> <span word="it">it</span> <span word="posed">posed</span> <span word="no">no</span> <span word="threat">threat</span> <span word="to">to</span> <span word="humans">humans</span> <span word="anyway">anyway</span>.</p><p>此时已经距离地球很近了，撞击概率是10%左右。这个尺寸的小行星进入大气层就会烧毁，所以对人类没有威胁。</p><p><span word="But">But</span> <span word="the">the</span> <span word="asteroid">asteroid</span>'<span word="s">s</span> <span word="trajectory">trajectory</span> <span word="would">would</span> <span word="bring">bring</span> <span word="it">it</span> <span word="very">very</span> <span word="close">close</span> <span word="to">to</span> <span word="the">the</span> <span word="geostationary">geostationary</span> <span word="ring">ring</span>, <span word="the">the</span> <span word="volume">volume</span> <span word="of">of</span> <span word="space">space</span> <span word="around">around</span> <span word="Earth">Earth</span> <span word="in">in</span> <span word="which">which</span> <span word="bodies">bodies</span> <span word="can">can</span> <span word="maintain">maintain</span> <span word="geostationary">geostationary</span> <span word="orbit">orbit</span>. <span word="That">That</span> <span word="space">space</span> <span word="is">is</span> <span word="packed">packed</span> <span word="with">with</span> <span word="satellites">satellites</span>.</p><p>但这颗小行星的轨道使它非常靠近地球静止环，这是地球周围的一部分空间，其中的物体可以在地球静止轨道内运行。这一空间里到处都是卫星。</p><p><span word="On">On</span> <span word="April">April</span> 28, <span word="this">this</span> <span word="asteroid">asteroid</span> - <span word="later">later</span> <span word="named">named</span> 2020 <span word="HS">HS</span>7 - <span word="skimmed">skimmed</span> <span word="past">past</span> <span word="Earth">Earth</span> <span word="at">at</span> <span word="a">a</span> <span word="distance">distance</span> <span word="around">around</span> <span word="nine">nine</span> <span word="times">times</span> <span word="closer">closer</span> <span word="than">than</span> <span word="the">the</span> <span word="average">average</span> <span word="distance">distance</span> <span word="of">of</span> <span word="the">the</span> <span word="Moon">Moon</span>.</p>
页:
[1]