太阳大小的透镜或能揭示外星大陆与海洋

Telescopes far beyond Pluto could use the Sun’s gravity to magnify a distant planet DANIEL CLERY W ill humanity ever be able to see the continents, oceans, and polar caps of a distant, Earth-like world? Even a 10-by-10-pixel image is almost unattainable: A space telescope would need a mirror 160 kilometers across to produce it, according to a preprint posted online late last year. A flock of smaller space telescopes or a vast array of instruments on Earth or the Moon operating in concert are no more feasible, because they would take centuries to gather enough photons. But there is one promising option, the preprint argues: using the Sun as a gi- ant lens, focusing light with its gravity. …