[One] thing that astronomers discovered early on was that, rather than being an asteroid, the interstellar interloper dubbed 3I/ATLAS was a comet.

"It is doing things that we expect comets to do. It's producing the types of gasses that we see comets produce. It's got a coma and a tail now pointed in the expected direction," said James Wray, a professor at the Georgia Institute of Technology's School of Earth and Atmospheric Sciences. "I would say the short summary is it looks generally like a comet. But in detail, there are some intriguing differences from solar system comets."