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

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.