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

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 enigmatic moons — including Titan, which has its own atmosphere, and icy 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 craft, 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 Saturn's 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.

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Gravity from Titan, Saturn's planet-sized moon, plays a key role in Cassini's final orbits. NASA is using the force to bend Cassini's course, a task that would otherwise require large amounts of fuel.

These two views of Titan show the new details about the moon's surface — including clouds and hazes in its atmosphere — that Cassini has revealed.

The first of the probe's final five orbits took it between the rings and the planet itself. Data from that fly-by is being sent back to NASA today.