The afterglow of a massive collision between two giant planets may have been detected for the first time. The wreckage of the collision could eventually cool and form an entirely new planet. If the observation is confirmed, it provides an amazing opportunity to watch the birth of a new world in real time and open a window into how planets form.
In December 2021, astronomers watching an otherwise unremarkable sun-like star saw it begin to flicker. For a few months, the visible light (the light we can see with our eyes) from this star continued to change. At times it would almost disappear, before returning to its previous brightness.
The star, which sits roughly 1,800 light years from Earth, was given the identifier ASASSN-21qj, after the ASASN-SN astronomy survey that first observed the star’s dimming.
