On Mercury, the ground tops 400 °C in daylight, yet NASA's MESSENGER probe confirmed water ice there. It hides at the bottom of polar craters that sunlight never reaches, because Mercury's axis is almost perfectly upright. In that eternal shadow, temperatures stay colder than −170 °C, cold enough to keep ice for billions of years.
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.