Astronomers using the Green Bank Telescope spotted surprisingly cold, dense hydrogen clouds embedded inside the Milky Way’s vast, super-hot Fermi bubbles—structures thought to be created by a recent, violent outburst from the galaxy’s core. Because such chilled gas should evaporate quickly in million-degree surroundings, its survival hints that the bubbles are only about a million years old. Ultraviolet data from Hubble backs the discovery, and the clouds’ million-mph speeds reinforce the bubbles’ youth. The find forces scientists to rethink how energy and matter flow through galaxies.
Astronomers using the Green Bank Telescope spotted surprisingly cold, dense hydrogen clouds embedded inside the Milky Way’s vast, super-hot Fermi bubbles—structures thought to be created by a recent, violent outburst from the galaxy’s core. Because such chilled gas should evaporate quickly in million-degree surroundings, its survival hints that the bubbles are only about a million years old. Ultraviolet data from Hubble backs the discovery, and the clouds’ million-mph speeds reinforce the bubbles’ youth. The find forces scientists to rethink how energy and matter flow through galaxies. Astronomers using the Green Bank Telescope spotted surprisingly cold, dense hydrogen clouds embedded inside the Milky Way’s vast, super-hot Fermi bubbles—structures thought to be created by a recent, violent outburst from the galaxy’s core. Because such chilled gas should evaporate quickly in million-degree surroundings, its survival hints that the bubbles are only about a million years old. Ultraviolet data from Hubble backs the discovery, and the clouds’ million-mph speeds reinforce the bubbles’ youth. The find forces scientists to rethink how energy and matter flow through galaxies.