The plucky little spacecraft named Cassini is nearing the end of its 13-year journey orbiting Saturn, but it’s still sending back some spectacular postcards. NASA has just released four new extreme close-ups of Saturn’s icy main rings.

Carolyn Porco is Cassini Imaging Team Lead at the Space Science Institute in Boulder, Colorado. She and her team are delighted with the new images, some of which get as close as 0.3 miles from the gas giant’s orbiting debris.

"As the person who planned those initial orbit-insertion ring images—which remained our most detailed views of the rings for the past 13 years—I am taken aback by how vastly improved are the details in this new collection," Porco said in a statement for NASA. "How fitting it is that we should go out with the best views of Saturn's rings we've ever collected."

The orbiter will make several dozen passes across the planet and over its rings in the next few months. Its grand finale phase of 22 orbits, which begins on April 26, will plunge the spacecraft straight through the gap between Saturn and its rings.

This is a long-exposure image of the outer edge of Saturn’s B ring, which is subject to the strongest gravitational disturbance in the rings due to the orbit of the moon Mimas.

This is a section of Saturn’s A ring. The specks on the image are caused by cosmic rays and intense radiation. The streaky, slightly larger objects are called propellers and are produced by "the gravity of unseen embedded moonlets," according to NASA.

These stripes or accumulations of particles are called density waves. Astronomers refer to the clumpy areas of disturbance as “straw.” The waves are the result of gravitational pull from Saturn’s moons Janus and Epimetheus.

All images courtesy of NASA/JPL-Caltech/Space Science Institute