If you’re looking for reasons why mankind hasn’t found aliens yet, you can come up with a whole bunch of them. We’ve never left our Solar System, never set foot on another planet, and while our telescope technology allows us to gaze at planets far, far away, we don’t possess the ability to see what’s actually on them. Searching for reasons why aliens haven’t found us, on the other hand, is a bit more difficult to answer. A new paper from Michael Hippke, a researcher with the Sonnenberg Observatory in Germany, provides one potential explanation, and it’s likely one that you’ve never considered before.
Hippke proposes that alien “space programs” might struggle with the technology required to send them into space, particularly if they reside on one of the many “Super Earths” that astronomers have located over the past few years. These massive, possibly-Earth-like worlds are up to twice the size of our planet, and that would mean a significant increase in the force of gravity. The result could be intelligent civilizations that just can’t push themselves off their own planet.
Hippke’s argument is that, because of the increased gravity of a planet larger than Earth, building a rocket to carry them into space would be such a monumental task that it would be a deal breaker. If aliens are using technology similar to our own — chemical fuels pushing rockets skyward — gravity is obviously a big consideration, but even on a planet twice the size of Earth it might not be an insurmountable obstacle.
As Dr. Seth Shostak, senior astronomer at the SETI Institute, writes in NBC News, Hippke’s theory seems to assume that the human race only just barely made it into space at all. The idea that mankind wouldn’t have been able to eventually achieve similar results in a higher gravity environment is sketchy at best. Would it have taken alien longer to achieve spaceflight if the gravity of their planet was significantly stronger? Perhaps, but even if the added challenge set them back by tens, hundreds, or even thousands of years, that’s a barely a blip on the timeline of the universe.
Nevertheless, it’s interesting to consider how potential alien civilizations might struggle with spaceflight depending on the specific conditions they are presented with. If (when?) we finally make contact with an extraterrestrial race, will we find that we had an easy go of things? Hopefully we don’t have to wait long to find out.