The farthest thing we’ve detected in space isn’t a star or galaxy, it’s the Cosmic Microwave Background, or CMB. This is essentially the afterglow of the Big Bang, the universe’s birth, captured in the microwave band of light. We’re looking at light that embarked on its journey just 380,000 years after the universe began. Through measuring its redshift, scientists estimate the CMB is currently about 46.5 billion light-years away from us in every direction. This impossible-to-comprehend distance indicates the universe’s diameter stretches 93 billion light-years. The discovery of the CMB in 1965 was a pivotal moment, offering strong support for the Big Bang model. For a deeper exploration, take the 6-minute deep dive: The Expanding Universe Explained.
