Nasa's Cassini spacecraft captures best ever image of propeller belts in the rings of Saturn

Nasa's Cassini mission to Saturn has captured the sharpest image so far of a region in the A ring known as the "propeller belt". The propellers are the small, bright features that appear like double dashes.

For the first time, Nasa has captured swarms of these features, of varying sizes. Cassini first discovered the features when it arrived in the vicinity of Saturn in 2004. The images obtained then were low resolution ones, where it was difficult to interpret.

One of the earliest images obtained of propellers. Image: Nasa.

One of the earliest images obtained of a propeller. Image: Nasa.

The propellers are actually gaps in the ring system caused by tiny objects known as moonlets. Moonlets are smaller than the conventional moons of Saturn, but larger than the particles that make up the rings. Some of the larger propellers have been named, and Cassini has even targeted the propellers in close fly bys. The Bleriot propeller and the Earhart propeller are among the largest known propellers, and have been targeted for fly bys so scientists could better understand these objects.

The Bleriot propeller on the left, and the Earhart propeller on the right. Image: Nasa.

The Bleriot propeller on the left, and the Earhart propeller on the right. Image: Nasa.

The propellers are the first objects in ring systems to be tracked by scientists. The study of propellers on the rings of Saturn allow researchers to learn more about how the solar system itself formed, as the conditions in the ring system are similar to the conditions of the accretion disks in the early days of star system formation. The moonslets are obscured by the disturbed matter around them, and are comparatively small, relative to the disturbance they create in the rings.

Daphnis, a moon of Saturn that Cassini discovered. Image: Nasa

Daphnis, a moon of Saturn that Cassini discovered. Image: Nasa

The moons of Saturn cause the gaps in the ring system by clearing their orbit of all debris. The moonlets are too small to be able to do this, but the propellers represent their attempts to create such permanent gaps. Daphnis, a tiny moon, also disrupts the matter in the ring system, and creates 8 kilometer long ripples along the Keeler gap. The image was captured on 19 April, using the narrow angle camera on board.

Cassini would later slingshot around Titan and begin a final set of orbits around the gas giant, these are now known as the "grand finale" dives. Cassini is scheduled to crash into Saturn on 15 September to prevent potential contamination of the moons of Saturn, which could support life.


Published Date: May 12, 2017 11:54 am | Updated Date: May 12, 2017 11:54 am