People often say starlight comes from stars that are long gone. But nearly every star visible to the naked eye lies within a few thousand light-years, while stars live for millions or even billions of years. The odds that one has died since its light set off are tiny. The night sky you are looking at is, with rare exceptions, very much alive.
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.