Water vapor found in asteroid belt comet by James Webb Space Telescope.
The James Webb Space Telescope (JWST) has discovered water vapor on a rare main belt comet, Comet 238P/Read, which is missing carbon dioxide, a mystery in itself. The presence of water vapor on the comet is a cosmic clue into the origins of Earth's ancient water source and how it got there. JWST also found another unusual trace of water vapor last month on a rocky exoplanet known as GJ 486 b, which is said to be 30% larger than our Earth and three times as massive.