GJ 3378b could be just large enough and just close enough to its star to host life (Picture: Nasa) Aliens could call a planet about a 282 million-year drive away home, scientists say. GJ 3378b is an exoplanet – a planet not inside our solar system – that is more than double the size of Earth. It’s 25 light-years away from us, so it would take you 141 million years on a bullet train to get there, according to Nasa’s Exoplanet Catalog. Astronomers at the University of California, Irvine, have found that GJ 3378b’s atmosphere could be the right thickness for life to survive. Paul Robertson, UC Irvine associate professor of astronomy and lead author, said: ‘This one’s exciting. ‘It’s one of our closest cosmic neighbours. 25 light-years sounds like a long way, but the Milky Way is about 100,000