Earth's 'Older Cousin' 60 Percent Bigger (And That's A Good Thing!) | Video

Kepler-452b size is important because it receives 10 percent more energy from its Sun than we do from ours. That mass protects it from experiencing "runaway greenhouse effect and the loss of its water inventory," according to NASA. This animated graph shows the energy Kepler 452b (and Earth) are receiving over the course of billions of years.