Oh, if Galileo could be here today.
After a five-year journey, the NASA spacecraft Juno finally made it to Jupiter on Monday. As it approached orbit, a remarkable view of Jupiter’s moons circling the massive planet came into focus.
It's a sight that humans have only ever imagined — one celestial body orbiting another. (Watch video above.)
Jupiter's four largest moons. (Photo: NASA/Reuters)
Jupiter has 62 known moons, but the four visible in the video are the largest. The innermost moon is called Io, followed by Europa, Ganymede, and Callisto.
These moons are known as the "Gallilean satellites," and their historical significance makes this video even more special.
In the 17th century, the Italian astronomer Galileo observed the four moons over the course of a few nights, and noticed that they were orbiting Jupiter. This lead him to the realization that Earth is not, in fact, the centre of the universe — a discovery that completely changed humanity's understanding of the cosmos.
"For the first time in history, we look upon these moons as they orbit Jupiter and share in Galileo's revelation," NASA said.