Ask Ethan: Could there be dark matter aliens out there? | by Ethan Siegel | Starts With A Bang! | Feb, 2025

Only 5% of the Universe is made of normal “stuff” like we are. Could there be dark matter or dark energy life, or even aliens, out there?

When it comes to the entirety of the Universe, the “stuff” that we’re made out of — atoms and their constituent particles — plays an important role. Protons, neutrons, and electrons, in both atomic, nuclear, and ionic configurations, make up all of the light-emitting and light-absorbing structures that we know of. Stars, galaxies, gas, dust, plasma, black holes, and more are all made of these simple ingredients, with little room for anything else. And yet, they make up just 4.9% of the Universe. Overall, the most abundant form of cosmic energy is dark energy, making up 68% of the cosmic energy budget, followed by dark matter, which makes up 27% of all that’s out there.

Well, if the normal stuff, or stuff like us, can make such interesting shapes, structures, and creatures, what about the dark stuff? That’s what our reader Wesley wants to know, writing in to inquire:

“is it possible we’re the outliers? If dark energy… and dark matter [are so much more abundant than normal matter], could there be this whole other dark world of elements, energy, etc., that evolved dark…