On a truly dark night, the Andromeda Galaxy is visible to the naked eye, one of the most distant things you can see without a telescope. It lies about 2.5 million light-years away. The photons hitting your retina have been traveling for 2.5 million years, which means they set off long before our species appeared.
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.