It’s easy to get disheartened about the utter lack of evidence of the existence of extraterrestrial life. The universe is an unimaginably large place, yet so far it seems like we’re all alone. Of course, it could just be that aliens are too far away or perhaps we’re just looking for the wrong things in the wrong places. Maybe we’re an aberration, or, given the unfathomably long timelines of the cosmos, it could be that civilizations rarely develop in close proximity at the same times. Still, scientists with SETI and other organizations remain optimistic that we’ll discover alien life within the next few decades. There’s never been a better reason to take care of your health.
To add to the list of reasons why we’re so utterly forever alone out here in the terrifyingly empty reaches of space, a German astrophysicist has just published a new theory for why we haven’t found any aliens. According to Michael Hippke, a scientist at the Sonneberg Observatory, one of the most significant challenges facing distant alien races could be their own planets’ immense gravitational pulls. Recent exoplanet discoveries have revealed that so-called “Super-Earths” are fairly common in the habitable zones of their stars. However, as Hippke points out, the immense size of these Super-Earths can create incredibly strong gravitational forces which essentially ‘trap’ aliens on the surface due to the energy requirements needed to escape them.
Hippke told Space.com that any advanced alien civilizations on these types of planets might be unable to leave the surface by means of spaceflight, and thus might look for other means of reaching out:
Civilizations from super-Earths are much less likely to explore the stars. Instead, they would be to some extent arrested on their home planet and, for example, make more use of lasers or radio telescopes for interstellar communication instead of sending probes or spaceships.
Hippke says humans are pretty luck to find ourselves on a planet lightweight enough to support spaceflight, but that “other civilizations, if they exist, might not be as lucky.” Still, Hippke concludes his study by theorizing that space elevators or nuclear-powered rockets might be an option for these civilizations. As with all of these studies, I can’t help but wonder if our thinking about aliens is limited by the facts of our own existence.
The limits of our senses and our own technology lead us to think that all other life must ‘work’ the same ways life on Earth does. We think that any potential alien races would only be able to reach space by means of spacecraft, or that they even want to reach space at all, but who knows what hypothetical aliens on other planets might be like? Maybe they want to be left alone. Maybe they can send their consciousnesses through space. Maybe their bodies are spacecraft. The point is, we have no Earthly idea what’s out there, on Super-Earths or any other types of planets.