100 years ago, scientists had limited knowledge about the cosmos. #PretendToBeATimeTraveler with our Cosmic Times educational series, and hop through important moments that defined our understanding of how the universe began and how it changed over time: https://go.nasa.gov/3uGkceV #NASAUniverse
Telescopes help us look back in time — the farther the object, the longer its light takes to reach us! You can #PretendToBeATimeTraveler with @NASAWebb as it collects light from 13.5 billion years ago, when the first stars and galaxies were forming: https://go.nasa.gov/32ZCHAv #NASAUniverse
After the Big Bang, the universe was like a hot soup of particles (i.e. protons, neutrons, and electrons). When the universe started cooling, the protons and neutrons began combining into ionized atoms of hydrogen (and eventually some helium).
