How hot is the sun?
I have it on very good authority that it s more than 20 degrees, for sure.
The Sun is a ball of nuclear plasma so large its own weight keeps it from exploding. Very cool, but also quite hot. However, the Sun has a complicated interior structure, and surprisingly large temperature variations, both on and under its surface. Today, we’re going to look at why this is, and how we know.
A ‘Pumpkin Sun’ composite image created by NASA in 2014. Colored gold-yellow, with active regions being brighter for “a particularly Halloween-like appearance”. Image credits NASA.
A lot of the things happening on Earth are, ultimately, fueled by energy from the Sun. We see that energy as sunshine, feel it hot on our skin on a clear day. It drives winds, and it powers rain cycles. Almost all life on Earth is fed by plants capturing sunlight. It’s very fortunate for us, then, that the Sun produces a monumental amount of energy. Just a fraction of its output reaches our pl