Let there be dark: to keep the cosmos in view, sky watchers must fight to keep the Earth from being enveloped in a fog of artificial light

Natural History, Oct, 2002 by Neil deGrasse Tyson

Without a view of Earth, telescopes built on the Moon could point in any skyward direction, without the risk of contamination from the Earth's electromagnetic emanations. Not only that, night on the Moon lasts nearly fifteen Earth days, which would enable astronomers to monitor objects in the sky for days on end, much longer than they could from the Earth. And because there is no lunar atmosphere, observations conducted from the Moon's surface would be as good as observations of the cosmos from Earth orbit. The Hubble Space Telescope would lose the bragging rights it now enjoys.

Furthermore, without an atmosphere to scatter sunlight, the Moon's daytime sky is almost as dark as its night, so everybody's favorite stars hover visibly in the sky, right alongside the disk of the Sun. A more pollution-free place has yet to be found.

On second thought, I retract my earlier callous remarks about the Moon. Maybe our neighbor in space will one day become the astronomer's best friend after all.

Neil deGrasse Tyson, an astrophysicist, is the Frederick P. Rose Director of New York City's Hayden Planetarium and a visiting research scientist at Princeton University.