Podcast Episode
Flickering Star Reveals Rare Evidence of Two Planets Colliding
March 12, 2026
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Astronomers at the University of Washington have captured rare evidence of a catastrophic collision between two planets orbiting a distant sun-like star. The event, detected through unusual flickering patterns in the star's light, may closely mirror the ancient impact believed to have formed Earth's moon roughly four and a half billion years ago.
A Star That Went Bonkers
A seemingly ordinary star located roughly eleven thousand light-years from Earth has revealed something extraordinary. Astronomers noticed that the star, known as Gaia20ehk, had begun flickering wildly after years of steady, predictable light output. The cause was not the star itself, but enormous quantities of rock and dust passing in front of it.The Collision Unfolds
A doctoral candidate at the University of Washington stumbled upon the anomaly while combing through archival telescope data. Starting in 2016, the star showed three brief dips in brightness. Then, around 2021, its light output became completely erratic. The breakthrough came when the team examined infrared data and discovered something striking: as visible light dimmed, infrared light spiked dramatically, indicating the obstructing material was extremely hot, glowing at roughly nine hundred Kelvin.Grazing Impacts Before the Big Crash
The team's analysis paints a dramatic picture. Two planets spiralled ever closer together, initially producing a series of grazing impacts that caused limited infrared energy. Then came the main catastrophic collision, sending vast clouds of superheated debris across the system. The debris cloud now orbits the star at approximately one astronomical unit, nearly the same distance as Earth from the Sun.A Mirror of Our Own Origins
The discovery is one of only a handful of planetary collisions ever observed and bears the closest resemblance yet to the giant impact hypothesis, the leading theory for how Earth's moon formed some four and a half billion years ago. At its current orbital distance, the scattered material could theoretically cool and solidify into something resembling our own Earth-Moon system, though that process could take years or even millions of years.What Lies Ahead
The finding points to an exciting future for planetary collision research. Once the Vera C. Rubin Observatory in Chile begins its Legacy Survey of Space and Time, astronomers estimate it could detect around one hundred similar collisions over the next decade. For now, the dust around this remarkable star continues to evolve, and astronomers are watching closely.Published March 12, 2026 at 2:34pm
