According to Betül Kaçar, an astrobiologist at the University of Wisconsin-Madison, organisms developing the ability to “eat” radiation isn’t out of the realm of possibility—in fact, it has happened already on Earth.
“Life found a way to eat pretty much anything it can on this planet. It’s quite remarkable,” she says. “If you think about it, the fact that life can capture photons [or particles of light] is ‘eating radiation.’ … For many microbes, the photons are great resources of energy. So phototrophs are an example of radiation-eating organisms on this planet.” Plants are well-known phototrophs, but sea slugs are unexpected ones, making their ability to gain fuel from radiation just as remarkable as that of the Astrophage microbes.