NASA's Cassini probe just got closer to Saturn than ever before - here's what its death spiral is revealing

NASA/JPL-Caltech

An illustration of Cassini's "Grand Finale" at Saturn.

NASA's Cassini probe is plunging to its death.

The nuclear-powered spacecraft has orbited Saturn for 13 years, and sent back hundreds of thousands of images. The photos include close-ups of the gaseous giant, its famous rings, and its icy moons - including Titan, which has its own atmosphere, and Enceladus, which has a subsurface ocean that could conceivably harbor microbial life.

To prevent Cassini from crashing into and contaminating any of those hidden oceans, the space agency has directed the robot, which is running out of fuel, onto a crash course with Saturn.

On Monday, the space probe conducted the first of its final five orbits around the planet, dipping into its atmosphere, according to NASA. It's all part of the "Grand Finale" for the $3.26-billion, 20-year mission, which will end on September 15 as the spacecraft dives to its demise and burns up like a meteor.

"As it makes these five dips into Saturn, followed by its final plunge, Cassini will become the first Saturn atmospheric probe," Linda Spilker, Cassini project scientist at JPL, said in a press release. "It's long been a goal in planetary exploration to send a dedicated probe into the atmosphere of Saturn, and we're laying the groundwork for future exploration with this first foray."

These last passes will reveal new data about Saturn, its atmosphere and clouds, the materials making up its rings, and the mysterious gravity and magnetic fields of the gas planet.

"It's Cassini's blaze of glory," Spilker previously told Business Insider. "It will be doing science until the very last second."

Here's what the probe's final spiral is revealing so far.