How long does it take to travel to the nearest star at the speed of light?

1 Answer
George C.
Oct 9, 2016

Approximately 4.2 years

Explanation:

The nearest star (apart from the Sun) is currently Proxima Centauri, which is about 4.2 light years away. (The Sun is a mere 500 light seconds or so from the Earth)

That means that the light we currently see from Proxima Centauri started its journey about 4.2 years ago.

If an astronaut were able to travel close to the speed of light, then from the perspective of observers at home, the journey would take at least 4.2 years.

Note however, that the astronaut would experience somewhat less time, depending on how close to the speed of light they were travelling.

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