Orion, the Hunter

Two of the brightest stars in the evening sky lie at opposite corners of the rectangle: bright red Betelgeuse at the northeastern corner and even brighter Rigel at the southwest.

Near the center of the rectangle, look for a short diagonal line of three stars — Orion's belt. And extending south from the belt, you'll see another, fainter line of stars that forms Orion's sword.

One of the objects in Orion's sword isn't a star at all. It's a nebula — a cloud of gas and dust that's like a giant fluorescent bulb. Hot young stars inside the nebula pump energy into its gas, causing the gas to glow.