This outstanding composition shows the blue ion tail and the grey/white dust tail of comet NEOWISE as it nears its closest approach to Earth. The dust tail is curved and diffuse while the ion tail is straight and highly collimated. Both are caused by extremely different physical processes. (DAMIAN PEACH / IAN SHARP)

Why Does Comet NEOWISE Have Two Tails?

For the first time in many years, there’s currently a comet visible to the naked eye in Earth’s night sky: comet NEOWISE.

For the first time in many years, there’s currently a comet visible to the naked eye in Earth’s night sky: comet NEOWISE. It’s visible to most of the world’s population, currently positioned just…