The Moon is just past full tonight, so it casts a brilliant glow across the winter landscape. Unfortunately, it casts that same glow into the sky. Its light is scattered by molecules in the air — the same thing that happens with sunlight, only not as bright. Still, it’s enough to overpower the view of many fainter stars — leaving the night sky looking a bit washed out. Luckily, there are plenty of bright lights that shine through the moonlight. Several of them are in Auriga, the charioteer, which is high overhead in mid to late evening. Several of its stars form a lopsided pentagon. The brightest is Capella, one of the brightest stars in the entire night sky. It represents a small goat riding on the charioteer’s shoulder. It’s actually a binary — two stars locked in orbit around each other. Both are yellow giants — stars that are much bigger and brighter than the Sun. They’re also much later in life than the Sun, which is why they’ve puffed up. The third-brightest point in the pentagon
