How can the solar corona be hotter than the surface? What has the Parker Solar probe learned so far? What do magnetic fields have to do with all this?

Are we “in range” of any potential supernovae? Has the Earth ever been hit in the past? And what about gamma-ray bursts from across the galaxy, are we safe from those?

How do black holes get close enough to merge? What causes them to emit gravitational waves, and where do the waves come from? What does the merger process look like?

How did Pluto get demoted? What makes a planet a planet anyway? Why do we now have so many different kinds of planets, and should we make things simpler?