Skip to main content
Became Hot Network Question
edited tags
Link
uhoh
  • 151k
  • 56
  • 505
  • 1.6k
Tweeted twitter.com/StackSpaceExp/status/1148698471194644480
Source Link
uhoh
  • 151k
  • 56
  • 505
  • 1.6k

Has anyone in space seen or photographed a simple laser pointer from Earth?

In the question How to make a green LED as visually bright as a 0 magnitude star? I worked out that a 100 mA green LED with a 10° half-angle 18 kilometers away would be as bright as a 0th magnitude star. So a 5 mW laser pointer with a miliradian divergence could potentially be seen even farther away, or at least photographed.

Question: Has anyone in space seen or photographed a laser pointer from Earth?

Note I'm asking about a laser pointer, not some high-powered laser used to bounce off of the Moon, or a powerful searchlight. Something that you can hold in your hand.