At the peak of each activity cycle, roughly every 11 years, the Sun's magnetic field turns completely upside down: north becomes south. This cycle sets the pace for sunspots, solar flares and auroras on Earth. So it takes about 22 years for the Sun to return to its original magnetic setup.
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.