In a solar eclipse, are we seeing it as the eclipse takes place in real time, or do we see it 8 minutes after it happens because that’s how long the light takes to travel from the sun?


closed as off-topic by DarkDust, James Jenkins, Hobbes, uhoh, Machavity Jan 25 at 14:20


  • "This question is about other space sciences (physics, weather, astronomy, etc), and does not directly pertain to space exploration as outlined in the help center." – DarkDust, James Jenkins, Hobbes, uhoh, Machavity

  • 1
    $\begingroup$ Welcome to Space Exploration! This is a good question, but probably better placed on astronomy.StackExchange - would the moderators consider moving it there? - In one of Jan Meeus's books, there's a chapter discussing similar topics at length (focusing on planet occultations, with some surprising answers!), but I don't have the books near me at the moment. $\endgroup$ – GNiklasch Jan 25 at 13:09
  • $\begingroup$ @GNiklasch I typically suggest them in flags, so they will surely see it. $\endgroup$ – peterh Jan 25 at 14:14
  • $\begingroup$ "real time" is a fraught term when light speed and astronomical distances are involved ;-). $\endgroup$ – Peter A. Schneider Jan 25 at 14:38

The Moon's orbit radius is about 384 400 km says wikipedia. Hence the sunlight eclipsed by the Moon reaches the Earth 1,28 s after passing close by the moon.

