Mary Anne Limbach

In the vast darkness of interstellar space, the rogue planet WISE 0855 flickers with a barely perceptible heat glow, like a cooling ember. Its temperature is only a few dozen degrees above freezing — if life existed there, it would see a sunless sky, in an eternal icy haze.

Astronomers pointed JWST at a planet near the star Epsilon Indi — a giant gas ball resembling Jupiter, just 12 light-years away. In thermal images, the planet shone like a lantern. But nearby they noticed a faint dot — like a firefly. Calculations showed that two objects describe the picture better than one. However, it's most likely a lens flare — like a ghost of a lamp.