A sunspot is a region where an intense magnetic field holds back the flow of heat from below. Its core is only around 3,500 °C, compared with about 5,500 °C around it. It looks black purely by comparison: set alone in the night sky, a single sunspot would shine dazzlingly bright. Some are larger than Earth.
A large share of Earth's water molecules formed in the interstellar cloud that existed before the Sun was even born, more than 4.6 billion years ago. You are literally drinking a cosmic fossil.
By day, the Martian sky looks butterscotch because of fine dust hanging in the air. But at dusk, those same grains scatter blue light forward, creating a bluish glow around the Sun. Rovers have photographed these blue sunsets: the exact reverse of what we see on Earth.