After two years of scanning the night sky, NASA's WISE infrared telescope has spotted millions of supermassive black holes and a type of galaxy never seen before. The hot, dust-obscured galaxies—hot DOGs—are very rare. Each emits as much light as 100 trillion suns, hidden behind a vast cloud of cosmic dust, reports Reuters. WISE spotted close to a thousand hot DOGs. Astronomers believe they form when spiral galaxies collide, making them the missing link between galaxies like our own, and elliptical galaxies.
WISE spotted more than 2.5 million supermassive black holes, more than twice as many as earlier surveys, by detecting the warm dust around them, reports Wired. "WISE has exposed a menagerie of hidden objects," a program scientist says. "We've found an asteroid dancing ahead of Earth in its orbit, the coldest star-like orbs known, and now, supermassive black holes, and galaxies hiding behind cloaks of dust."