Expansion is speeding up: distant galaxies are receding ever faster. In some 100 billion years, every galaxy beyond our Local Group, by then merged into a single big galaxy, will have slipped past our visible horizon. Any future astronomers would see only an island of stars in the dark, and would struggle to infer the Big Bang. We live at a lucky time.
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.