Iain Dale 7pm - 10pm
If You Look Through A Telescope Five Light Years Away, Are You Watching Earth Five Years Ago?
15 May 2018, 16:01 | Updated: 15 May 2018, 16:47
Mystery Hour Question
Name: Dan, London Bridge
Question: If you had a telescope five light years away from earth, would you be watching the earth from five years ago?
Name: Jessy, Eastleigh
Qualification: Former Spacecraft Satellite Manufacturer
Answer: The speed of light is 186,000 miles per second in a vacuum.
When you’re looking through a telescope at an object; the further away it is, the longer in the delay in the light you’re seeing.
For example, if you are are billions of miles away, stars in the night were formed millions of years ago yet are millions of miles away.
The further away you are, the further the delay is.