No Way Out? Aliens on 'Super-Earth' Planets May Be Trapped by Gravity
"Super-Earth" planets are giant-size versions of Earth, and some research has suggested that they're more likely to be habitable than Earth-size worlds. But a new study reveals how difficult it would be for any aliens on these exoplanets to explore space. To launch the equivalent of an Apollo moon mission, a rocket on a super-Earth would need to have a mass of about 440,000 tons (400,000 metric tons), due to fuel requirements, the study said. That's on the order of the mass of the Great Pyramid of Giza in Egypt.