Scientists recently found that a subtle optical illusion of Saturn’s ring tricked us into believing it is more massive than it really is for decades. The illusion was detected by two researchers while they were sifting through decade-old data in an attempt to recalculate the ring’s mass.
Phillip Nicholson and his fellow researcher Matt Hedman learned that the planet’s brightest ring, dubbed ring B, deceived scientists for decades through its unusual opacity. Because of a visual trick, optical instruments perceived the ring as seven times more massive than it really is.
The two researchers published a research paper on the new findings Jan. 22 in the journal Icarus. Study authors wrote in their analysis that the finding could play a significant role in deciphering how the gas giant developed the rings.
To the astronomers’ surprise, other rings were not affected by any optical illusion. The research team calculated their approximate mass indirectly, from the ripples that occur when the planet’s moons jostle one of the rings. Researchers explained that these density waves change shape if the rings’ density is higher.
Nevertheless, ring B is special. Because its structure is more complicated than other rings’, scientists’ attempts to measure its mass have been a matter of guesswork for decades. The teams based their estimates on the idea that the more mass a ring has the less transparent that ring should be.
So, because ring B is the most opaque of Saturn’s rings, scientists thought that it must be twice as heavy as Mimas, one of Saturn’s many moons. After taking another look on the imagery provided by NASA’s Cassini probe, the two astronomers detected faint density waves within ring B, which allowed them to reach the conclusion that the ring is actually less dense than previously thought.
In fact, the ring is seven times less massive than astronomers have believed for decades.
Still, the new findings do not suggest that ring B is not the most massive ring around the gas giant. Astronomers estimate that ring B is still the king, but they eagerly await for their hypotheses to be confirmed in September 2017, when Cassini will perform a final, but fatal plunge to the planet’s surface and end its mission.
Hopefully, the images taken during the probe’s final moments could help astronomers calculate the true mass of Saturn’s mysterious ring B once and for all.
Image Source: Wikimedia