Outer space is big. Really, really, really big. And that’s why NASA has no plans at present to send a spacecraft to any of the 1,876 known planets (as of January 9, 2015) beyond our solar system. Alpha Centauri is the nearest star system to our sun at 4.3 light-years away. Can’t we even go that far? The answer is … not easily. A distance of 4.3 light-years equals trillions of miles away from Earth – nearly 300,000 times the distance from the Earth to the sun.