What's up with: The Sun


This is the Sun, as photographed October 20th by Alan Friedman.

See those little plumes, rising like steam off the top and sides? That is not steam, says astronomy blogger Phil Plait. Instead, it's ...

the gas that follows magnetic loops piercing the Sun's surface. When we see them against the Sun's surface they're called filaments, and when they arc against the background sky on the edge of the Sun's disk they're called prominences.

They look so delicate, probably because they make the Sun look fuzzy, like a comfy blanket... but have no doubts on the fury and scale of what you're seeing here. See that little bright spot on the plume on the left, just above the Sun's edge? That spot is the same size as the Earth. Our planet is about 13,000 km (8000 miles) in diameter, so that one minor prominence is roughly 50,000 km high. That's 30,000 miles. And it's positively dwarfed by the Sun itself. A million Earths could fit inside the Sun.

It's neat—if somewhat ego-deflating. And there's more, read the rest at Bad Astronomy.