Look up into the night sky this summer and you may find a cup, but not one you can drink from.
The cup is Crater, a faint constellation located near Leo, Sextans, Hydra, Corvus, and Virgo. Its name comes from the Latin word for cup, which is also where we got our word for the cup-shaped indentations caused by asteroid impacts on the Earth, Moon, and other planets. Crater was one of the original 48 constellations cataloged by the Second Century Greek astronomer Ptolemy, and is still one of 88 officially recognized modern constellations.
The constellation contains 12 stars, four of which make up its shape. None of its stars are brighter than the third magnitude.
The brightest star is Delta Crateris, an orange giant. Other notable stars include Alpha Crateris, another orange giant, Beta Crateris, a blue-white star, and Gamma Crateris, a double star. Alpha Crateris is traditionally called Alkes, a name also meaning “cup.”
The constellation also includes a few deep sky objects – NGC 3511, a spiral galaxy with a slight bar; NGC 3887, a barred-spiral galaxy; and NGC 3981, a spiral galaxy with two wide spiral arms.
In Greek mythology, Crater is identified with the cup of the sun god Apollo. According to one myth, the cup ended up in the night sky because the god had sent his servant, the raven Corvus, to fetch him some water. On the way, the raven became distracted by some unripe figs. He waited for them to ripen so he could enjoy them, only remembering his task after he had eaten every one. When Corvus returned to Apollo, he lied and said that the water serpent, Hydra, had delayed him on his journey. The god saw through the raven’s excuses, and angrily scorched the bird with his rays, turning his feathers black and reducing his once beautiful voice to a rough caw. Apollo then flung the raven, cup, and serpent into the sky, where they remain to this day. To further punish the raven, Apollo set Hydra between him and the cup, preventing him from ever quenching his thirst.