What is the closest planet outside of our solar system?
1 Answer
It would be the exoplanet which is orbiting the star Proxima Centauri.
Explanation:
In August, 2016, astronomers confirmed the discovery of an exoplanet orbiting within the habitable reaches of Proxima Centauri, the closest star to Earth and part of the small star system; Alpha Centauri- a triple star system just over 4 light years away.
Its believed to have a mass of 1.3 of Earth- meaning its gravity would only be slightly more burdening, but means that it is likely to be a rocky planet as well.
It orbits Proxima Centauri every 11.2 (Earth) days, at only 1-tenth of the distance between Mercury and the Sun.
But why is it habitable? This is due to the fact it is a brown dwarf star, meaning it is incredibly small, and also less hot than our Sun, it is also a slowly burning Sun, and finds it incredibly difficult to nuclear burn hydrogen due to its small mass and is what is often known as a 'failed star'.
This discovery however, is not at all a failure, and gives us the best chance of finding life in a star system outside of our own, as well as it being in the peculiar place of a triple star system, and that the two other stars orbit each other (though, this still at some distance from one another).
Hope this helps!
-C. Palmer
