Right after the Big Bang, the Universe was one giant nuclear reactor. Between roughly 3 and 20 minutes, protons and neutrons fused into helium and a dash of lithium, then everything cooled too much. The result, still measurable today: about 75% hydrogen and 25% helium by mass, the raw material of every star.
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.