Friday 5 February 2016

The king of the rings

When we classify objects as opaque, transparent and translucent , we often think that the basis for this classification is the amount of matter in it, but here we are wrong( see my "translucent" post for more info). The new research of Saturn's ring has also pointed this out.

 According to a recent study of the rings using data from NASA’s Cassini mission. In their analysis, scientists found surprisingly little correlation between how dense a ring might appear to be — in terms of its opacity and reflectiveness — and the amount of material it contains.The new results concern Saturn’s B ring, the brightest and most opaque of Saturn’s rings, and are consistent with previous studies that found similar results for Saturn’s other main rings.

While the opacity of the B ring varies a lot but on the other hand its mass seemed to be constant.They “weighed” the nearly opaque center of the B ring for the first time — technically, they determined its mass density in several places — by analyzing spiral density waves. These are fine-scale ring features created by gravity tugging on ring particles from Saturn’s moons and the planet’s own gravity. The structure of each wave depends directly on the amount of mass in the part of the rings where the wave is located.

This research has laid important implications for their age, a more massive ring would evolve slowly than a less massive one, becoming darkened by dust from meteorites and other cosmic sources more quickly. Thus, the less massive the B ring is, the younger it might be, perhaps a few hundred million years instead of a few billion.

Despite the low mass found by Hedman and Nicholson, the B ring is still thought to contain the bulk of material in Saturn’s ring system. And although this study leaves some uncertainty about the ring’s mass, a more precise measurement of the total mass of Saturn’s rings is on the way. Previously, Cassini had measured Saturn’s gravity field, telling scientists the total mass of Saturn and its rings. In 2017, Cassini will determine the mass of Saturn alone by flying just inside the rings during the final phase of its mission. The difference between the two measurements is expected to finally reveal the rings’ true mass.

By : Aviral Srivastava 
find me on Instagram as : avirals_22

email me at : aviralsrivastava12@gmail.com



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