News for hackers. Stuff that matters.

A comment on Forgotten Soviet Moon Rover Beams Light Back to Earth.

Re:Forgotten Soviet Moon Rover Beams Light Back to Earth by adavies42 on Friday May 27, 2011 @03:44PM (#2592815)
> For every 1018 photons shot at the moon, only a single photon returns to the telescope.

Is that really 1018, or did 10^18 get mangled on its way onto the web?

[ Parent | on HN ]
Re:Forgotten Soviet Moon Rover Beams Light Back to Earth by dalke on Saturday May 28, 2011 @08:27AM (#2594339)
The latter. There's no way that it's reflecting a million watts back to the Earth's surface (1/1018 of the main beam power). Or to put it another way, with a beam "footprint" of 2km across, and with the size of the rover rather less than 100 m across, there's no way it alone could return that high a percentage of the light sent to it.
[ Parent | on HN ]