When we think of aliens, we think of spaceships. In fact, it’s hard to even conjure alien images outside the context of their monumental starships soaring through the solar system, or their flying saucers hovering above the White House lawn. But it just may be that aliens have no need for one of the most saturated tropes in all of science fiction.

New evidence and xenoarchaeological thought experiments are beginning to suggest that the way we visualize alien travel may be all wrong. While, yes, invariably somewhere in the universe there is another civilization that travels through the cosmos via spaceships, it’s looking more and more as if the truly advanced alien civilizations that haunt and fuel our imaginations may have no need for spaceships whatsoever. Here are 5 compelling reasons why:

Alien Life Travels in Asteroids



There is prevailing theory among some cosmologists that human life–in fact, all life on Earth–originated from elsewhere in the universe via an asteroid that struck the planet early in its history. Known as panspermia, and sometimes as exogenesis, the hypothesis suggests that organic components of life have spread throughout most of the universe via asteroids, meteoroids, and planetoids. Panspermia has gained traction in recent years after NASA announced the discovery that the amino acids necessary for life likely originated from meteorites.

There is also the idea that civilizations of aliens actually dwell inside giant asteroids. This idea was explored most brilliantly in Greg Bear’s novel Eon. So next week, when asteroid 2012 DA14 flies within 17,200 miles of the Earth, consider the possibility that one of the universe’s own homemade spaceships is passing by.

Aliens Deploy Robot Scouts



The premise here is: why send out a 100 year starship of your families when you can have robot scouts do it? A sufficiently advanced alien civilization will likely have produced strong artificial intelligence and would be able to equip drone-like satellites with extremely intelligent cybernetic computer systems that can scour the cosmos looking for signs of life. When they find it they report back, and infographics and powerpoint presentations are promptly put together.

Now, technically, you could think of these scouts as spaceships, but instead of being piloted by the aliens themselves they’re under the command of powerful alien technology. A very good reason to not have to travel hundreds of thousands of light years.

Aliens Travel/Communicate Through Psychic Powers



We often think of advanced alien civilizations as being masters of technology, post-singularity gods who wield glowing swords of technology the likes of which we can hardly imagine. But what if the universe contains alien species who have advanced through biological evolution to acquire telepathic powers beyond our wildest dreams?

Naturally, we define the already dubious notion of ESP in human terms, but the evolution of an alien species in a galaxy far far away may have unfolded completely different than life on Earth, producing extra-sensory powers that are, quite literally, unimaginable. These beings may be able to project their thoughts outward into the universe, traveling via consciousness to other star systems; similarly, they may be able to communicate across the vast distances of space using nothing more than thought.

Who knows? Perhaps the voices in our heads are alien philosophies hitchhiking across the stars.

Aliens are extreme bioforms



Aliens don’t need spaceships because they either live in or can fly directly through the ether of space. There have been many names proposed for such incredible creatures: zenoids, space animals, aeroforms, organic UFOs, etherians, bioforms.

The basic premise is that just as certain species on Earth can live in extremely hostile environments, such as volcanos or glaciers, so too can aliens. A drastically different alien physiology may have evolved in such a way that it can withstand the vacuum of space and, in fact, prefers it. Imagine the possibilities here: sentient organic species soaring through space….

Aliens are information



As explored in Stanley Kubrick’s 2001: A Space Odyssey, aliens could very well exist as pure energy forms that communicate through cosmic information pulses or perhaps even elements of dark matter. There’s no reason to think that in the vast incredible depths of the cosmos there isn’t some form of advanced biological computation. This would make possible the existence of sentient energy forms that travel in the same way that an electromagnetic pulse might.

Another example of this in fiction is Stanislaw Lem’s Solaris. It features an entire oceanic planet that is one giant alien consciousness.

Aliens Create Simulations



Nick Bostrom’s simulation theory proposes that because of the likelihood of an alien species experiencing a technological singularity and creating advanced simulations, it’s not only possible but probable that we are living in a simulation. Our entire universe has been methodically programmed, quark by quark, by godlike aliens who want to know how artificial minds and civilizations might develop, interact, flourish, and collapse.

These alien simulators would have no reason to travel around in spaceships because they are literally the overlords of our universe. Of course, what they do outside the simulation in their universe–the real universe–is anyone’s guess. Maybe they’re living in a simulation too…