Astronomers witnessed the apocalypse from across the galaxy as a planet slammed into a parent star. This event was long thought to occur in many star systems, including ours, but this is the first time it has been directly observed. Earth has an expiration date: in about 5 billion years, the Sun will run out of hydrogen fuel and turn into a red giant, swallowing Mercury, Venus and possibly Earth. This is a normal phase in the life cycle of many stars, and given how common planets are now, it was assumed that such an end-of-the-world scenario would occur regularly in the cosmos.

But it has never been directly observed until now. Astronomers from Caltech and MIT watched a sun-like star known as ZTF SLRN-2020, located about 12,000 light-years away, swallow a gas giant roughly the size of Jupiter over the course of several months.

The first clues to the story came when the Zwicky Transit Facility (ZTF) watched the star shine more than 100 times over a 10-day period before fading again. The original assumption was that it experienced a nova, an explosion that occurs when a white dwarf absorbs material from a companion star. But a closer look at the Keck Observatory cleared that up.

“I was looking for exploding stars called Nova,” said Kishalai De, the study’s lead author. “But Keck’s data showed that the star was not firing hot gas as expected from the new ones.

So the team continued to check the infrared data collected by the NEOWISE space telescope and found that the star glowed in infrared light for nine months before ZTF recorded the optical illumination. In fact, infrared radiation is still visible today, the team says.

Collecting the fragments, the researchers compiled the most likely story. The aging star began to expand until its surface reached the orbit of the unfortunate planet. Eventually, it was close enough for the planet to expel the hot gas from the star’s surface, and the planet itself began to disintegrate. Material from both objects was ejected into space, where it cooled to dust and formed the infrared signature seen by NEOWISE. This dangerous dance lasted about nine months until the inevitable end of the world.

“The planet sank into the core of the star and was swallowed whole,” De said. “While doing this, energy was being transferred to the star. The star blew up its outer layers to get rid of its energy. It got wider and brighter, and this lighting has been certified by ZTF.”

This incredible story is so humble. Perhaps in the distant future, aliens will see their own Apocalypse on Earth from afar and watch with the same scientific curiosity.