)
私たちの地球の周りには実に多くのモノが漂っている。これには危険な宇宙のゴミのほか活動中の人工衛星もある。科学者たちは、このゴミ全てをきれいにしてしまう独創的なアイデアをいくつか発表している。
オーストラリアの科学者たちは宇宙ゴミをレーザーで撃破する提案をしている。そして先月、欧州宇宙機関（European Space Agency）はe.DeOrbitというミッションを提案した。これは宇宙ゴミを網や銛で捕えるというものだ。
いかなる手段が認められたとしても、掃除を担当する乗組員は極度の困難に直面する。欧州宇宙機関（European Space Agency）による画像を見てみてほしい。ここには現在、地球低軌道にある全ての物体が示されている。
「何十年にもわたってロケットを打ち上げてきたことで、地球の周りは宇宙のゴミでいっぱいになってしまった。17,000超の追跡可能な物体はコーヒカップより大きいものであるが、破滅的な衝突をすることで宇宙での活動ミッションを脅かしている」としたうえで、「たとえ1センチの大きさのものでも、手榴弾ほどの力で衝突することになる」と、同機関は述べている。
NASAによると、軌道上には50万を超える破片があり、これらはビー玉かそれより少し大きいくらいだという。この中には使用された打ち上げロケット、機能していない人工衛星、さらには「宇宙飛行士が捨てたナットやボルト」もある。これらは時速28,000kmのスピードで移動することもある。
NASAがコメントするには、軌道上宇宙ゴミは「宇宙そして地球上にいる人、そこにある物の安全」にとってのリスクになっているという。同機関の推定では、毎日１つの破片が地球に舞い戻っているが、大気中に再侵入してくる軌道上宇宙ゴミが原因の負傷、器物損傷は今のところ報告されていない。
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