Saturn's moon Enceladus' 'tiger stripes' mystery explained

James Marshall
December 10, 2019

Saturn's moon Enceladus has been shrouded in mystery since its discovery in the late 18th century, but now researchers believe they have solved what causes the moon's "tiger stripes", according to a new study.

Astronomers did not know why the stripes appeared to form only on the southern pole, as well as why they were so evenly spaced across that surface. It just so happens the stripes on the south pole cracked ahead of those on the north pole.

"First seen by the Cassini mission to Saturn, these stripes are like nothing else known in our solar system", lead author Doug Hemingway said in an emailed statement.

First discovered by Cassini, the lines are parallel and evenly spaced, being approximately 130km long and 35 km wide. "My colleagues had previously thought about how to make the first fracture, but we still wanted to understand why there are multiple fractures and why they are roughly parallel". "No other icy planets or moons have anything quite like them".

The crew was significantly attention-grabbing in understanding why the stripes have been concentrated exclusively on the moon's south pole and the way the cracks grew to become so evenly spaced. The stripes could have formed at either end of the moon, but it was the south's that opened up first. The tidal stresses produced by this endless loop create heat, deforming the moon, which is why Enceladus is able to maintain liquid water underneath its icy crust.

Saturn's tiny, frozen moon Enceladus is a odd place. This deformed shape causes the ice sheets at the poles to be thinner and more susceptible to splitting open, they found.

The tiny moon is pulled by Saturn's gravity, which exert tidal forces on Enceladus. At some point in the moon's history, while it was going through a cool-down period, water froze beneath the caps.

A handful of worlds are thought to have liquid water oceans beneath their frozen shell, however exclusively Enceladus sprays its ocean out into area, the place a spacecraft can pattern it. Icy material from Enceladus' ocean spews into space through these stripes, or fissures, in the moon's surface.

An up-close look at the tiger stripes on Enceladus.

Due to their comparatively skinny ice, the poles are probably the most inclined to cracks. In this case, the process resulted in a total of two secondary fissures and one tertiary fissure, dubbed Damascus, Cairo, and Alexandria (these names are borrowed from Arabian Nights).

Nonetheless, it did not simply freeze again up once more. It stayed open, permitting ocean water to spew from its crevasse that, in flip, induced three extra parallel cracks to type.

Co-author Max Rudolph of the College of California stated: 'Our mannequin explains the common spacing of the cracks, ' the examine's co-author, Max Rudolph, added. Eventually, something had to give, resulting in the cracks seen 35 kilometers away on either side of the Baghdad fissure, where the depth of the ice was around 5.2 kilometers (3.2 miles) thick. Now researchers have revealed the physics behind the fissures that open up and spill ocean water out of the icy surface, and create those stripes.

As the water spills out of those cracks, it drops back down as ice, which builds up at the edge of the fissure and weighs it down.

For a larger moon, its own gravity would be stronger and prevent the additional fractures from opening all the way.

So, these stripes might exclusively have shaped on Enceladus.

Hemingway and the other researchers noted that they've been able to study Enceladus' ocean, thanks to these fissures, which continue to widen and narrow over time.

'Our modeling of the bodily results skilled by the moon's icy shell factors to a doubtlessly distinctive sequence of occasions and processes that would enable for these distinctive stripes to exist'.

However the brand new proposal, that tidal forces from Saturn are inflicting the eruptions, explains the delay completely.

'The brand new proposal is known as a technique to get a delay within the eruptions.

She added that outcomes from final yr's Enceladus flyby will should be analyzed to substantiate this.

Other reports by Click Lancashire

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