'Ice cube' clouds discovered at the galaxy's center shouldn't exist — and they hint at a recent black hole explosion

The Fermi bubbles are two enormous orbs of gas and cosmic rays that tower over the Milky Way, covering a region roughly as large as the galaxy itself. These giant space bubbles may be fueled by a strong outflow of matter from the center of the Milky Way.

Two of the strangest structures in the galaxy just got even stranger.

Ballooning above and below the Milky Way's center like a massive hourglass, the mysterious Fermi bubbles loom large over our galaxy. These enormous twin orbs of superheated plasma have been gushing out of the galactic center for millions of years. Today, they span some 50,000 light-years from tip to tip, collectively making them half as tall as the Milky Way is long.