Astronomy Picture of the Day: The cosmic microwave background

The oldest observable light in the universe is in the same wavelength range that cooks your food — microwaves! The cosmic microwave background was emitted about 13.8 billion years ago, when the universe was just 380,000 years old. https://t.co/4O9mxgofbP #MicrowaveOvenDay pic.twitter.com/alC1x0HsIR

— NASA Universe (@NASAUniverse) December 6, 2021