… and it’s not just a Supermoon, its a Blood Supermoon! Last one before 2033.
Why does the Earth’s shadow make the moon look red rather than, say, blue like the sky? Short answer: The Sun’s light is filtered through our atmosphere. We see the effect in sunsets. The filtered light curves around the Earth’s sphere and illuminates the Moon. Here’s one link. And another.
While I was looking this up, I found NASA’s Tour of the Moon. Enjoy it while we wait for the Blood Moon.