The Cassini spacecraft has already dived between Saturn and its rings to analyze what lies in between the two. Cassini's first dive was on April 26 and the spacecraft is scheduled to perform more dives before it finally crashes into the planet's surface.

Even as scientists plan Cassini's second dive, the analysis of the data recovered from the first dive has bewildered them. The scientists were puzzled to learn that the region between the rings and Saturn's surface is quite dust-free.

Dust-Free Zone

This absence of dust in the region is not what scientists had expected since the rings itself are primarily composed of dust particles.

"The region between the rings and Saturn is 'the big empty,' apparently. Cassini will stay the course, while the scientists work on the mystery of why the dust level is much lower than expected," Cassini Project Manager Earl Maize of NASA's Jet Propulsion Laboratory remarked.

Comprehending the presence of immense dust in the area, scientists had specially built Cassini's saucer-shaped antenna. This feature was supposed to protect the spacecraft from the dust. Scientists noted that the presence of dust would have severely restricted Cassini's ability to observe.

Nearly 21 more dives are planned with the spacecraft out of which, 4 will pass via the inner fringes of Saturn's rings. During these four dives, the saucer-shaped antenna is likely to come in handy and will shield Cassini.

The antenna is fitted with a Radio and Plasma Wave Science or RPWS sensor, which is able to detect particles that come into contact with the sensor. During the first dive, the antenna detected many hits while Cassini swerved through the ring's edge. However, in the region between Saturn and its rings, the sensor only picked up a few collisions.

Scientists monitoring the sensor's audio output expected to hear a lot of pops and cracks during the dive on April 26, but were surprised to hear very few of these.

Cassini's Second Dive

Following the first-ever exploration between the rings and Saturn's surface in human history, Cassini engineers will again maneuver the spacecraft between the two. The second dive is scheduled to take place on Tuesday, May 2, at 3.38 p.m. EDT.

According to NASA, this dive will take place in the vicinity of the first dive region. To calibrate the magnetometer, engineers have rotated the spacecraft faster than ever before.

During the close approach to Saturn, Cassini will be unable to send data and, therefore, will share its findings on Wednesday, May 3.