Far from city lights, a pale streak crosses the night sky. It's the disc of our own galaxy, seen edge-on from within: billions of stars too distant to pick out individually. In 1610, Galileo became the first to see, through his telescope, that this milky haze was made of countless stars.
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.