Centaurus is home to some of the night sky’s great treasures, including our closest neighbor stars and the Milky Way’s largest globular cluster. Yet most of us in the United States don’t get to see them. They’re so far south that they always stay below the horizon. Centaurus represents a centaur — a mythological creature that was half man, half horse. According to some versions of the story, he was Chiron — the wisest of all the centaurs. He tutored Hercules, Perseus, and many other young heroes in music, medicine, and other arts. But Hercules accidentally shot Chiron with a poisoned arrow. Chiron was immortal, so he suffered in agony. Zeus eventually allowed him to die — then placed him in the stars. The centaur’s greatest treasure is Alpha Centauri — a system of three stars. They’re the nearest stars beyond the Sun. The closest of the three is Proxima Centauri, just four and a quarter light-years away. It’s too faint to see without a telescope. But the other two stars, which are a to
