• Question: how far away is the closest star to earth (not including the sun!!)

    Asked by eshanip1017 to Alan, Francesca, Nick on 20 Mar 2014.
    • Photo: Francesca Day

      Francesca Day answered on 20 Mar 2014:

      The closest star to Earth is called Proxima Centauri. It’s 4.243 light years from Earth. A light year is the distance light travels in a year. Light travels at 299800000 metres per second, so in a year it travels 299800000 x 365 x 24 x 60 x 60 = 9460000000000000 m. Therefore Proxima Centauri is about 40000000000000000 metres away! That’s 4 followed by 16 zeroes or 40 million billion.

    • Photo: Alan Fitzsimmons

      Alan Fitzsimmons answered on 20 Mar 2014:

      Francesca’s right. In fact, astronomers have just finished using a space telescope called WISE to search for any even fainter stars that are even closer, but didn’t find any in the whole sky! So Proxima Centauri definitely is the closest.

    • Photo: Nick Wright

      Nick Wright answered on 20 Mar 2014:

      The closest star to Earth is Proxima Centauri, which is about 4 light years from Earth. This gives you a really good idea of how big space is, because even though its the closest star to Earth it takes light (which is the fastest thing we know of) 4 years to get there!