In July 1054, Chinese astronomers recorded a "guest star" visible in daylight for 23 days, and at night for almost two years. It was an exploding star, a supernova. Its debris now forms the Crab Nebula, about 6,500 light-years away. At its heart, the star's corpse, a neutron star, still spins around 30 times a second.
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.