Author: m1k3y

Cracks in Pluto’s Moon Could Indicate it Once Had an Underground Ocean

In Charon’s case, this study finds that a past high eccentricity could have generated large tides, causing friction and surface fractures. The moon is unusually massive compared to its planet, about one-eighth of Pluto’s mass, a solar system record. It is thought to have formed much closer to Pluto, after a giant impact ejected material off the planet’s surface. The material went into orbit around Pluto and coalesced under its own gravity to form Charon and several smaller moons.
 
Initially, there would have been strong tides on both worlds as gravity between Pluto and Charon caused their surfaces to bulge toward each other, generating friction in their interiors. This friction would have also caused the tides to slightly lag behind their orbital positions. The lag would act like a brake on Pluto, causing its rotation to slow while transferring that rotational energy to Charon, making it speed up and move farther away from Pluto.

“Depending on exactly how Charon’s orbit evolved, particularly if it went through a high-eccentricity phase, there may have been enough heat from tidal deformation to maintain liquid water beneath the surface of Charon for some time,” said Rhoden.
“Using plausible interior structure models that include an ocean, we found it wouldn’t have taken much eccentricity (less than 0.01) to generate surface fractures like we are seeing on Europa.”

“Since it’s so easy to get fractures, if we get to Charon and there are none, it puts a very strong constraint on how high the eccentricity could have been and how warm the interior ever could have been,” adds Rhoden. “This research gives us a head start on the New Horizons arrival – what should we look for and what can we learn from it. We’re going to Pluto and Pluto is fascinating, but Charon is also going to be fascinating.”

Based on observations from telescopes, Charon’s orbit is now in a stable end state: a circular orbit with the rotation of both Pluto and Charon slowed to the point where they always show the same side to each other. Its current orbit is not expected to generate significant tides, so any ancient underground ocean may be frozen by now, according to Rhoden.

Cracks in Pluto’s Moon Could Indicate it Once Had an Underground Ocean

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Massive ‘ocean’ discovered towards Earth’s core

The water is hidden inside a blue rock called ringwoodite that lies 700 kilometres underground in the mantle, the layer of hot rock between Earth’s surface and its core.

The huge size of the reservoir throws new light on the origin of Earth’s water. Some geologists think water arrived in comets as they struck the planet, but the new discovery supports an alternative idea that the oceans gradually oozed out of the interior of the early Earth.

“It’s good evidence the Earth’s water came from within,” says Steven Jacobsen of Northwestern University in Evanston, Illinois. The hidden water could also act as a buffer for the oceans on the surface, explaining why they have stayed the same size for millions of years.

Massive ‘ocean’ discovered towards Earth’s core

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The Fifth Element Is Starting to Come True

But as the iPhone becomes its own sort of Multipass, and those funny lopsided cigarettes Bruce Willis smokes in the movie become a real design, it’s interesting to see how Luc Besson’s legendary sci-fi movie was more prescient than we would’ve guessed in the 1990s.

The Fifth Element Is Starting to Come True

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fuckyeahdarkextropian:

Jill Tarter: 30 Seconds On Why We Search For Aliens

We should be searching for life beyond the earth because we want to understand what the laws of chemistry and physics have produced in this universe. Are we the only life there is? Are we the only intelligent species, or are we one of many? How do we fit in? It’s a very old question, humans have asked it, and we want to find the answer.

It is that simple and profound.

Cosmic Anthropology for Beginners.

(Source: https://www.youtube.com/)
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blech:

US Embassy London, on Twitter:

A very 21st century swearing in; becomes the 1st U.S. Ambassador to take the oath over an electronic device.

(ht jomc, tominsam; more from the Washington Post)

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“This new paper definitely supports the idea that trousers were invented for horse riding by mobile pastoralists, and that trousers were brought to the Tarim Basin by horse-riding peoples,” remarks linguist and China authority Victor Mair of the University of Pennsylvania.

Previously, Europeans and Asians wore gowns, robes, tunics, togas or — as observed on the 5,300-year-old body of Ötzi the Iceman — a three-piece combination of loincloth and individual leggings.

Earlier research on mummies from several Tarim Basin sites, led by Mair, identified a 2,600-year-old individual known as Cherchen Man who wore burgundy trousers probably made of wool. Trousers of Scythian nomads from West Asia date to roughly 2,500 years ago.

Mair suspects that horse riding began about 3,400 years ago and trouser-making came shortly thereafter in wetter regions to the north and west of the Tarim Basin. Ancient trousers from those areas are not likely to have been preserved, Mair says.

Horse riding’s origins are uncertain and could date to at least 4,000 years ago, comments archaeologist Margarita Gleba of University College London. If so, she says, “I would not be surprised if trousers appeared at least that far back.”

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