Complex sentence: His collection, "The Cosmos Poems", was commissioned by the American Museum of Natural History to celebrate the opening of the new Hayden Planetarium in 2000, and he won the PEN/Voelcker Award for Poetry in 2002.
Split into simpler sentences: His collection, "The Cosmos Poems", was commissioned by the American Museum of Natural History to celebrate the opening of the new Hayden Planetarium in 2000. He won the PEN/Voelcker Award for Poetry in 2002.