When stars like our Sun run out of the fuel for nuclear fission, they puff out their outer atmosphere, and their core collapses down into a dense hot ball of atomic nuclei and electrons. This process isn’t entirely kind to any surrounding solar system that may be present. As the star evolves toward a white dwarf, it first expands out to eat any inner worlds, and then the material it puffs off blasts anything that is left.

Over time, the blasted-off material blows away, and we can look in at the white dwarf, and sometimes we can see from its light that it has been eating what little might remain of its solar system.

In newly announced results from research done by then UCLA undergraduate Ted Johnson, the white dwarf G238-44 has been spotted devouring a diverse variety of objects. In its light, there is evidence of everything from Mercury-like rocky worlds to icy solar system objects getting vaporized on the star’s surface.

While the destruction of worlds kind of indicates those worlds aren’t exactly good for current life, we can use their destruction to look for the chemistry that would have been good for past life. According to collaborator Benjamin Zuckerman: Life as we know it requires a rocky planet covered with a variety of volatile elements like carbon, nitrogen, and oxygen. The abundances of the elements we see on this white dwarf appear to have come from both a rocky parent body and a volatile-rich parent body — the first example we’ve found among studies of hundreds of white dwarfs.

Part of the reason we’re able to see this destruction is this white dwarf is still fairly young and we’re seeing, and I quote from the press release here: The true scale of the chaos, showing that within 100 million years after the beginning of its white dwarf phase, the star is able to simultaneously capture and consume material from its nearby asteroid belt and its far-flung Kuiper belt-like regions.

It’s a star-eat-planet universe out there, but these messy eaters are giving us the tool to say that yes, life could exist out there among the stars… or at least it could find the chemistry it needs.

More Information

NASA press release

UCLA press release