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Methane dunes found on Pluto by NASA spacecraft



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NASA / JHUAPL / SWRI

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New Horizons data showed that Pluto is geologically diverse and dynamic

Scientists say they found evidence of frozen methane dunes on Pluto.

The research, published in the journal Science, suggests that the distant world is more dynamic than previously thought.

Pluto's atmosphere was felt to be too thin to produce the characteristics known in deserts on Earth.

The results are from the analysis of the frightening images of NASA's New Horizons mission, which flew near Pluto in July 201

5.

Following an epic solar system epoch that lasted almost a decade, New Horizons accelerated at 58,536 km / h (36,373 mph), collecting data.

In their study, the researchers explain how they studied images of a plain called Sputnik Planitia, parts of which are covered with dune fields.

They are near a series of 5 km high water mountains.

The scientists conclude that the dunes are 0.4-1 km apart and that they consist of particles of methane ice with a diameter between 200 and 300 microns – roughly the size of grains of sand.

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NASA / JHUAPL / SWRI

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In the lower half of this image of Pluto's Sputnik-Planitia region are dunes

The main author of the article is Dr. med. Matt Telfer, a physicist at the University of Plymouth. He told the BBC News: "We can not see individual grains, but we are able to identify dunes and characterize their basic physical parameters and the density of the atmosphere under which they were formed.

" And We can measure some basic things, how far they are apart, and at least estimate the wind speeds that they form.

"We can feed all this back into a physical model and deduce how big the grains need to be."

To form, the dunes need an atmosphere that is dense enough to withstand the wind allow a supply of dry particles and a mechanism that lifts particles from the ground.

At first glance, none of these conditions seem to exist on Pluto.

But Dr. Telfer and his colleagues estimate that the dunes lie in one of the windiest areas of Pluto and reach wind speeds of up to 10 m / s – enough to keep particles moving.

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NASA / JHUAPL / SWRI

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Pluto's atmosphere was perceived as too thin to create wind dunes by the wind alone

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NASA / JHUAPL / SWRI

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Pluto's strange "snake skin terrain" can not represent dunes, but ice blades

The wind is created when air flows down from the neighboring mountains and sublimates even frozen material – or turns directly into gas.

They believe that the dunes consist of methane and perhaps nitrogen, and that there is a "reservoir" of methane in the snowpack of the mountains.

As for the process of "lofting" Looking at the grains from the ground, the paper indicates that the driver could expect a slight warming from the distant sun and the temperature could rise above the freezing point of nitrogen: – 230 ° C.

With this under-surface ice being heated, methane crystals should allow nitrogen ice to sublime – and that would allow the methane crystals to reach the atmosphere.

Dr. Telfer says the analysis gives Pluto a new insight and also changes our view of it.

"It's really exciting to be able to look at this world and realize that it's not just a frozen, icy blob in the outer reaches of the solar system, but that a dynamic world is still changing and still forming." , he said.

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NASA / JHUAPL / SwRI / Steve Gribben

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Graphic: New horizons fly past the Kuiper belt 2014 MU69 2014 object in January 2019

This feeling is reflected in an article accompanying the science paper by Prof. Alexander Hayes, an astronomer at Cornell University in Ithaca.

He quotes the late Sir Patrick Moore, the BBC's famous host of Sky at Night, who describes Pluto in 1955 as "… plunged into eternal twilight, still, barren and touched by the cold of death …" and says that this perspective must shift.

Prof. Hayes says we now know Pluto as a "geologically diverse and dynamic" world driven by heat, extreme seasons, and sublimating ice.

He adds that it is not the boundary of the solar system, as Patrick Moore has suggested, but the "gateway" to the uncharted realm of the Kuiper belt.

And it might be that dunes themselves are a fascinating new feature

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NASA / JHUAPL / SWRI

Pluto now connects Earth, Mars, Venus, Saturn's Titan and even the Comet 67P – What a European Space Agency (Es a) mission landed on – as Houses in the Dunes.

And Professor Monica Grady from the Open University told me that the discovery raises fascinating questions about whether there are dunes on the worlds in other star systems.

"It makes you realize that you Your thoughts need to be open to the idea that familiar objects on different planetary bodies must have formed in their own way, "she said.

" What it does make you think n What is there behind the solar system because we can not see its surfaces at the moment, but we will do it and then we will probably see familiar things – we will see dunes and they will take us to the dunes of Pluto or the dunes Earth, but they will have formed differently.

New Horizons is now approaching another object in the Kuiper Belt, known as the 2014 MU69, which is due to haul itself out of hibernation next week and scheduled for January 1, 2019.

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