Amazing raw Cassini images from this week

When Saturn is at its closest to Earth, it's three-quarters of a billion miles away—or more than a billion kilometers! That makes these raw images from the ringed planet all the more remarkable.

Nearly every day, the Cassini spacecraft beams back what it sees at Saturn and the images are put up on this NASA website. This week, for example, it was checking out Saturn's rings. We have a few of the pictures below, plus an older picture of the entire planet for reference.

Saturn's rings are believed to be about 4.4 billion years old—that's close to the age of the Solar System itself. Astronomers, however, have only known about them since the 1600s, when Galileo Galilei was trying to make sense of some funny-looking shapes on either side of the planet in his telescope.

According to NASA, the particles in the rings range from dust-sized to mountain-sized. Some of Saturn's dozens of moons act as shepherds to the rings, keeping gaps open. You can read more about what we know about their origins here.