GLIESE 581c has got to be the ultimate tourist destination. Discovered in April this year, it is the first rocky planet beyond our solar system with anything like a pleasant climate. How mind-blowing would it be just to stroll along its beaches – surely it must have beaches – or watch the planet’s red-dwarf sun setting in a scarlet blaze over the alien landscape.
There’s just one little problem to consider before you rush to book your ticket. Gliese 581c is 20 light years away – over a million times the distance from Earth to the sun. The journey there would make NASA’s best efforts to explore our…
