The National Digest

A Proposed Space Telescope Would Use Earth’s Atmosphere As A Lens

BIG SHOT  The bending of starlight caused by Earth’s atmosphere could be used to create a giant telescope, one scientist suggests, by placing a detector out in space (illustrated).

One astronomer has suggested a possible work-around: Turn the entire Earth into a telescope lens by using the planet’s atmosphere to bend and focus light.

When light from stars hits Earth’s atmosphere, the light bends, or refracts. That bending concentrates the rays, focusing them in a region of space on the opposite side of the planet. Put a spacecraft in the right spot — say, orbiting 1.5 million kilometers from Earth — and it could catch the focused rays, says David Kipping of Columbia University (SN: 10/14/17, p. 22). Instruments aboard the craft might be able to collect more light from dim objects than is possible by current telescopes on Earth. That means the terrascope, as Kipping calls his design, could potentially make ultrasensitive measurements, for example, revealing new features of exoplanets, such as mountain ranges or clouds, he says.

Read more…