If you look off to the northwest after sunset tonight, you’ll find a star low in the sky. That northwestern star is named Arcturus, which means, “bear guard” or “bear chaser.” That’s because Earth’s rotation causes this star to follow or chase the constellation of Ursa Major, the Great Bear in the Sky, to the north of Arcturus (you’ll recognize part of the Great Bear as the Big Dipper.) Arcturus is the fourth brightest star in the night sky; it’s about 36 light years away – that’s roughly two hundred and sixteen trillion miles from earth - in the constellation Boötes, the Shepherd. This is an agricultural constellation that ancient farmers used to keep track of when to plant and harvest the crops. In the springtime, Boötes can be found in the eastern sky after sunset; now, half a year later, the shepherd has gone over to the other side of the sky, a celestial reminder of harvest time.