Scientists at NASA were absolutely floored when the NASA Cassini spacecraft headed in between Saturn’s famous rings and discovered something most unexpected: absolutely nothing. Cassini is gearing up for its final death dive in the solar system’s second large planet, and it appears that the gas giant hasn’t finished divulging some incredible secrets.

After two passes of the huge gaps between Saturn’s rings, scientists were astonished to find absolutely nothing in this vast area of space between the rings, not even a little bit of space dust which they had expected to find. That means the region between the rings and Saturn is totally devoid of any sort of material, whereas the rings themselves are filled with fast moving ice and space debris.

Cassini has brought tremendous scientific breakthroughs to NASA since being launched back in 1997 and arriving at Saturn in 2004. It has 22 dives scheduled between the rings that will hopefully yield to more breakthroughs, before it finally plunges to its death into Saturn in September.

“The region between the rings and Saturn is ‘the big empty,’ apparently,” said Cassini Project Manager Earl Maize of NASA’s Jet Propulsion Laboratory in Pasadena, California, in a statement. “Cassini will stay the course, while the scientists work on the mystery of why the dust level is much lower than expected.”

“It was a bit disorienting — we weren’t hearing what we expected to hear,” said William Kurth, RPWS team lead at the University of Iowa, Iowa City. “I’ve listened to our data from the first dive several times and I can probably count on my hands the number of dust particle impacts I hear.”