Gigantic Water Vapor Cloud Detected Around Ancient Quasar

Astronomers detected an immense reservoir of water vapour around quasar APM 08279+5255 (more than 12 billion light-years away), amounting to about 100,000 solar masses or roughly 140 trillion times all Earth's oceans, spread across hundreds of light-years. The water’s spectral signatures reveal a warm, dense gas environment, making it a useful tool for studying conditions in the young universe; the “largest ever” label is observational, reflecting current instrument limits rather than a universal cosmic ranking.