A mysterious question mark in space may be a galaxy collision Sciences

Christopher Brett, a scientist at the Space Telescope Science Institute, thinks the shape could be a merger of two galaxies. It is probably billions of light years away and is much further than Herbig-Haro 46/47. According to Brett, there are many galaxies outside our Milky Way.

Galaxies grow and evolve over cosmic time and can collide with their neighbours. “And when that happens, it can deform into all kinds of different shapes, including what appears to be a question mark,” Brett says.

Scientists say the shape of the question mark may also be caused by the gravitational pull between the two galaxies. “The question mark hook is very much like what we call a tidal tail. This is the stream of stars and gas that kind of took off and flew into space.”

Experts say it is likely the first time this particular shape has been seen. But that doesn’t mean it didn’t happen before. Most galaxies have had some collisions like this throughout their history, Brett said, “but they didn’t last long.”