Astronomers have potentially witnessed a rare cosmic event: the collision of two planets orbiting a distant star. The dramatic event occurred approximately 11,000 light-years from Earth, around a sun-like star named Gaia20ehk. Initial observations revealed unusual fluctuations in the star’s brightness, prompting further investigation.
Anastasios (Andy) Tzanidakis, a doctoral candidate in astronomy at the University of Washington, first noticed the anomalies even as reviewing older telescope data. He explained that stable stars like our Sun typically exhibit a relatively consistent level of luminosity.
“The star’s light output was initially nice and flat, but starting in 2016 it had these three dips in brightness. And then, right around 2021, it went completely bonkers,” said Tzanidakis. “I can’t emphasize enough that stars like our sun don’t do that. So when we saw this one, we were like ‘Hello, what’s going on here?’”
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Further analysis indicated that the changes in light weren’t originating from the star itself. Instead, large quantities of dust and hot material were passing in front of the star, partially blocking its light as observed from Earth. Researchers believe this debris field is the result of a catastrophic collision between two planets within the system.
This event likely generated fragments of rock and material that spread throughout the star system, creating a debris cloud still visible today. According to scientists, directly observing planetary collisions of this magnitude is extremely rare. The observation provides a unique opportunity to study the processes that may have shaped our own solar system.
“It’s incredible that various telescopes caught this impact in real time,” Tzanidakis said. “There are only a few other planetary collisions of any kind on record, and none that bear so many similarities to the impact that created the Earth and moon. If One can observe more moments like this elsewhere in the galaxy, it will teach us lots about the formation of our world.”
The research, published on March 11, 2026, in The Astrophysical Journal Letters, suggests that events like this are crucial for understanding how planets and solar systems form.
James Davenport, an astronomer at the University of Washington involved in the research, noted that planetary collisions can have a significant impact on the potential for life to emerge. “Seberapa langka peristiwa yang membentuk Bumi dan Bulan? Pertanyaan ini sangat penting bagi astrobiologi,” Davenport stated.
He explained that the presence of the Moon helps maintain Earth’s stability, influencing everything from ocean tides to climate dynamics. This discovery offers a rare chance for scientists to directly observe cosmic processes that may have also occurred during the early history of our solar system. The findings underscore the ongoing quest to understand the conditions necessary for planetary habitability.
(rns/rns)
