APOD: Pluto's Bladed Terrain (2017 Oct 05)

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APOD: Pluto's Bladed Terrain (2017 Oct 05)

Postby APOD Robot » Thu Oct 05, 2017 4:07 am

Image Pluto's Bladed Terrain

Explanation: Imaged during the New Horizons spacecraft flyby in July 2015, Pluto's bladed terrain is captured in this close-up of the distant world. The bizarre texture belongs to fields of skyscraper-sized, jagged landforms made almost entirely of methane ice, found at extreme altitudes near Pluto's equator. Casting dramatic shadows, the tall, knife-like ridges seem to have been formed by sublimation. By that process, condensed methane ice turns directly to methane gas without passing through a liquid phase during Pluto's warmer geological periods. On planet Earth, sublimation can also produce standing fields of knife-like ice sheets, found along the high plateau of the Andes mountain range. Known as penitentes, those bladed structures are made of water ice and at most a few meters tall.

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Re: APOD: Pluto's Bladed Terrain (2017 Oct 05)

Postby madtom1999 » Thu Oct 05, 2017 8:01 am

I walked the high moors in the UK in very cold weather. You often come across blades of ice like those mentioned. Close examination shows they have not been formed by sublimation but by condensation - at the heart of each one was a blade of grass. As it was something I was familiar with since childhood I never gave it too much attention but if memory serves me correctly the ice extended well beyond and above the grass blade. I'd imagine at the high pressure areas on the blade sublimation could take place but there was definitely more condensation on the low pressure parts.

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Re: APOD: Pluto's Bladed Terrain (2017 Oct 05)

Postby orin stepanek » Thu Oct 05, 2017 1:06 pm

Ah Pluto; little planet that could! Once rejected as a planet; has shown that it has a lot of amazing secrets that are now being studied! I say go Pluto; you earned your spot in the universe! :D
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Re: APOD: Pluto's Bladed Terrain (2017 Oct 05)

Postby neufer » Thu Oct 05, 2017 3:02 pm

http://www.markhorrell.com/blog/2014/ev ... e-highway/ wrote:
Everest’s magic miracle highway
Mark Horrell, January 8, 2014

<<When the 1922 Everest expedition team arrived at their base camp in the Rongbuk Valley, Tibet, they already knew from their reconnaissance expedition the previous year that their approach to the summit of Everest lay up a side valley known as the East Rongbuk. But while they were familiar with its geography, they knew little of the terrain they would find there. What they found when they came to ascend it in 1922 was a tumbling mass of jagged ice towers the size of buildings, completely impractical to climb over even by today’s standards. They kept away from this impenetrable barrier for as long as possible by keeping to the left hand side of the valley, but when they were finally forced onto it they found there was a route between these impossible pinnacles after all, on the medial moraine which formed a narrow sliver of rock down the middle of the glacier.

Unlike the penitentes formations many people see on Aconcagua and other mountains in South America, which tend to be about the height of a man and formed by sun and wind on fresh snow over the course of a single season, these are dozens of metres high and created by the pressure of the glacier crushing its ice into ridges as it gradually flows down the valley. We called them sharks’ fins, and they must have seemed a difficult proposition to skilled climbers, never mind Tibetan porters carrying heavy loads.

Although many of the accounts written by members of the 1922 and 1924 expedition teams are quite understated about the difficulties they encountered, one that offers some insight is that of the cameraman John Noel: “Between Frozen Lake and Snowfield Camps the glacier was twisted and broken into a belt some two miles wide of broken, splintered bergs of ice, some towering to a hundred feet in height. Here the men would strap steel spikes to the soles of their boots and set out along one of the strangest paths imaginable. They would find their way, turning and twisting in every possible direction, past the towers and pinnacles of ice, avoiding fissures fifty feet deep, descending walls of ice a hundred feet in depth, following old widened crevasses, climbing ladders that we cut in the ice, guided by a line of little flags we fixed to wooden pegs hammered to the tops of ice hillocks … Bergs and cliffs and crevasses blocked the way a dozen times to the first exploring party, and were circumvented only by retracing steps and starting afresh from some new direction.”

Anyone who’s seen John Noel’s recently re-released and slightly surreal film of the 1924 expedition, The Epic of Everest, might wonder whether they weren’t in fact doing the Hokey Cokey up the East Rongbuk Glacier. But this maze-like solution to the problem of ascending it clearly still existed in 1934, when the eccentric Yorkshireman Maurice Wilson went that way. Lacking any climbing skills he had a wild dream of climbing Everest solo and unsupported, and persuaded three Sherpas from Darjeeling to guide him to the foot of the mountain. They stopped in the Rongbuk Monastery at 5100m, leaving him to continue alone. He found the easy moraine route on the lower part of the East Rongbuk, and managed to reach John Noel’s Frozen Lake Camp at around 6000m without undue difficulty. Above this, however, he became lost and confused and failed to reach ABC (known then as Camp 3) at all during his first attempt.

So when did this straightforward route up moraine start getting called the Magic (or Miracle) Highway? Who coined the term, and is it the Magic Highway or the Miracle Highway? I’ve been searching for the answer to this question during some research for a book I’m writing, but have so far drawn a blank (as the bishop said to the actress). As far as I’m aware nobody used the term during the four major British expeditions to Everest of the 1930s, and for nearly half a century afterwards hardly anyone went that way. After the Second World War the Chinese annexed Tibet and the country became closed to outsiders. Two big Chinese expeditions to the north side of Everest took place in 1960 and 1975.

It occurred to me that perhaps the words magic and miracle are being used interchangeably due to a translation of the phrase into English from another language. One of the first westerners to attempt Everest from the north when Tibet opened up to foreigners again was Reinhold Messner. He made a solo, unsupported ascent along a new route across the North Face in 1980. I recently read his book about the climb, The Crystal Horizon, to see if it held the key, but I discovered Messner found nothing magical about the route up the East Rongbuk Valley: “It is the only place in the world’s mountains where yaks can climb to 6500 metres. That is possible only because a mound of detritus winds between two mighty streams of ice as far as the ice face under the North Col.”>>
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Re: APOD: Pluto's Bladed Terrain (2017 Oct 05)

Postby FLPhotoCatcher » Thu Oct 05, 2017 4:33 pm

How do they know they are "blades"? The terrain looks to be composed of rolling hills, not blades. Is there a close-up of the knife-like ridges?

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Re: APOD: Pluto's Bladed Terrain (2017 Oct 05)

Postby jack.priebe@yahoo.com » Thu Oct 05, 2017 4:41 pm

What is the cause of the little green dot on the far left of the pic? LGM base station?

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Re: APOD: Pluto's Bladed Terrain (2017 Oct 05)

Postby neufer » Thu Oct 05, 2017 5:03 pm

Click to play embedded YouTube video.
FLPhotoCatcher wrote:
How do they know they are "blades"?

The terrain looks to be composed of rolling hills, not blades.

They don't know.
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Re: APOD: Pluto's Bladed Terrain (2017 Oct 05)

Postby ta152h0 » Thu Oct 05, 2017 11:32 pm

This, in my book of facts, is worth the few bazilion dollars to build the infrastructure anr the intellectual property to get this image. When Prof Kaku sain nothing is faster than light, I sdidn't realise that is true when I watched astudy on the Big Bang and prof Krauss hade divived the event, not in 133.4 bil light years but in the first second into billionth of a second, anot just one billionth but in several of the in the deboninator. in the first one expansion to the Earth.s diametr wich does mean nothing was faster than light. What a class that must have been ......
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Re: APOD: Pluto's Bladed Terrain (2017 Oct 05)

Postby neufer » Fri Oct 06, 2017 2:35 am

ta152h0 wrote:
This, in my book of facts, is worth the few bazilion dollars to build the infrastructure anr the intellectual property to get this image. When Prof Kaku sain nothing is faster than light, I sdidn't realise that is true when I watched astudy on the Big Bang and prof Krauss hade divived the event, not in 133.4 bil light years but in the first second into billionth of a second, anot just one billionth but in several of the in the deboninator. in the first one expansion to the Earth.s diametr wich does mean nothing was faster than light. What a class that must have been ......
https://en.wikipedia.org/wiki/Washington_Initiative_502 wrote:
<<Washington Initiative 502 (I-502) "on marijuana reform" appeared on the November 2012 general ballot, and passed by a margin of approximately 56 to 44 percent. Initiative 502 was credited for encouraging voter turnout of 81%, the highest in the nation. Initiative 502 defined and legalized small amounts of marijuana-related products for adults 21 and over, taxes them and designates the revenue for healthcare and substance-abuse prevention and education.>>
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Re: APOD: Pluto's Bladed Terrain (2017 Oct 05)

Postby ta152h0 » Fri Oct 06, 2017 4:01 am

I don't do marijuana and never have.
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