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They could toss a couple up into orbit and scan the whole earth...maybe?
by UncleEntity 8y ago
They could toss a couple up into orbit and scan the whole earth...maybe?
- dan-robertson 8y agoReflecting a laser from earth all the way back to space is hard. The recently launched NASA satellite to look at the extent of polar ice fires a laser at earth and looks at the reflection. Ice is reasonably reflective yet even then the satellite gets about 1 photon back for every 1e12 it sends out. Firing a large laser is expensive in terms of energy and expensive in terms of temperature: once a satellite is hot, it is not very easy to call down. All you can do is try to radiate the heat away but that’s not so easy or effective.