Neptune takes about 165 years to circle the Sun. Discovered in 1846, it did not complete its first full orbit since then until July 2011. None of its discoverers, nor their children, lived to see a single Neptunian year go by. The next one will wrap up around 2176.
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.