NASA’s Cassini spacecraft just made a daringly close flyby of Saturn’s most mysterious moon, Dione. According to Clarkesville Online, the unmanned ship soared by Dione at 1:12 pm PDT on Tuesday, June 16, coming within just 321 miles of the moon’s surface.

As the Cassini probe soared above the moon, its cameras and spectrometers gathered information about a region on the moon known as “Eurotas Chasmata,” which was first observed 35 years ago by NASA’s Voyager probe. Back then, the Eurotas Chasmata looked like a collection of bright, wispy streaks of light. Astronomers at the time guessed that they might have been reflective material pushed to the surface as a result of the moon’s inner geologic activity, like an ice volcano.

Cassini’s recent flyover has brought a challenging perspective to that theory. Cassini’s cameras produced a series of sharp images, which revealed that the bright streaks appeared to be a complex network of canyons with blindingly bright walls, also known as linea.

Cassini will try to determine the chemical composition of any small particles coming from Dione, whose presence would indicate small-scale seismic activity on the strange moon. Engineers in Pasadena, California expect to begin receiving more images from Cassini’s mission over the next few days.

This pass was Cassini’s fourth planned flyby of the strange moon. This targeted encounter required the use of a propulsion maneuver that allowed engineers to steer the craft right towards the moon.

In 2011, Cassini coasted just 60 miles over the surface of the moon, and will soar past Dione one final time on August 17^th of this year.

Cassini will depart Dione’s orbit at the end of 2015, when it will shift its mission to explore the unknowns of the space in between Saturn and its mysterious rings.