doi.org/10.3847/2041-8213/ae3ddc
Credibility: 989
#eXOPLANET
Astronomers have discovered something extraordinary in a star system located about 11,000 light-years from Earth: strong evidence that two planets collided violently, generating a huge amount of dust and hot rocks that still affect the light of the star around which they orbited
The star, called Gaia20ehk, is similar to our Sun and, for a long time, shone in a stable and predictable way.
However, while analyzing old telescope data, astronomy student Anastasios Tzanidakis, from the University of Washington, noticed something strange.
Starting in 2016, the star’s light showed three dips in brightness, and around 2021 the behavior became completely irregular and intense-something that stars like the Sun simply don’t do.
The researchers realized that these variations were caused by large amounts of rocks and dust passing in front of the star, blocking part of its visible light.
At the same time, infrared observations showed the opposite: a strong increase in brightness, indicating that the material was very hot and glowing on its own.
This suggests that, initially, the two planets approached each other in a spiral, suffering grazing impacts that produced little heat.
Then came the main catastrophic collision, which released enough energy to heat all that matter.
This type of event is rarely observed in real time.
Planetary systems form from disks of gas and dust around young stars, and in the first few million years the environment is chaotic: planets and protoplanets frequently collide, destroy each other, or are ejected.
Over time, the system stabilizes.
Capturing such a collision requires luck-the debris needs to be aligned between us and the star, and the telescopes need to be observing at the right moment.
In the case of Gaia20ehk, several different instruments recorded the phenomenon exactly when the light from the collision reached us.
What makes this discovery even more fascinating is its similarity to an event that likely occurred in our own Solar System about 4.5 billion years ago.
At that time, a Mars-sized body called Theia collided with the young Earth, ejecting material that later coalesced to form the Moon.
Here, the debris disk orbits the star at roughly the same distance that Earth is from the Sun (one astronomical unit).
Over time-perhaps in a few million years-some of this dust and rocks may cool and clump together, forming something resembling a planet and its satellite.
Scientists emphasize that the Moon plays important roles for life on Earth: it helps protect the planet from asteroids, creates tides that mix chemistry and biology in the oceans, and may even influence tectonic activity.
Understanding how often collisions like this occur around other stars is fundamental to astrobiology-that is, to knowing how common habitable worlds like ours are.
This observation, published in “The Astrophysical Journal Letters,” shows how the universe still holds surprises for us.
In the future, the new Vera C.
Rubin Observatory in Chile should detect up to about a hundred similar events in the next decade, allowing astronomers to study in detail how planets form and evolve.
For now, the Gaia20ehk case gives us a rare live glimpse of a violent process that helped shape our own home in the cosmos.
Published in 03/18/2026 02h29
Text adapted by AI (Grok) and translated via Google API in the English version. Images from public image libraries or credits in the caption. Information about DOI, author and institution can be found in the body of the article.
Reference article:
Original study: