A new study suggests that most of Earth's carbon originated in the outer solar system and didn't arrive here until the late stages of planetary development. The study, led by researchers at Yale and Columbia, is based upon an analysis of magma droplets called "melt inclusions" from historic volcano eruptions in Hawaii, including the Keanakākoʻi eruptions from 1500 to 1840 and the Kīlauea Iki eruption in 1959.