SCIENTISTS PUZZLE OVER PLUTO’S POLYGONS
By Irene Klotz
NEW
YORK (Reuters) - New pictures relayed by the first spacecraft to visit distant
Pluto show odd polygon-shaped features and smooth hills in an crater-free
plain, indications that the icy world is geologically active, New Horizons
scientists said on Friday. “We had no
idea that Pluto would have a geologically young surface,” said lead researcher
Alan Stern, with the Southwest Research Institute in Boulder, Colorado. “It’s a
wonderful surprise.” The goal of the $720 million New Horizons mission is
to map the surfaces of Pluto and its primary moon Charon, assess what materials
they contain and study Pluto’s atmosphere. http://dlvr.it/BZxszz
SOURCE/LINK:
Science | Fri Jul 17, 2015 3:47pm EDT
Scientists puzzle over Pluto's polygons
NEW YORK | BY IRENE KLOTZ
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New pictures relayed by the first spacecraft to
visit distant Pluto show odd polygon-shaped features and smooth hills in an crater-free
plain, indications that the icy world is geologically active, New Horizons
scientists said on Friday.
“We had no idea that Pluto would have a
geologically young surface,” said lead researcher Alan Stern, with the
Southwest Research Institute in Boulder, Colorado. “It’s a wonderful surprise.”
The goal of the $720 million New Horizons mission
is to map the surfaces of Pluto and its primary moon Charon, assess what
materials they contain and study Pluto’s atmosphere. Launched in 2006, the
spacecraft traveled 3 billion miles (4.88 billion km) to fly through the Pluto
system on Tuesday. About 1 percent of the 50 gigabytes of data recorded in the
10 days leading up to the close encounter with Pluto has been relayed back to
Earth.
Still, the early results show that frozen Pluto,
where surface temperatures reach 400 degrees below zero Fahrenheit (minus 240
Celsius), is challenging theories about how icy bodies can generate heat to
reshape their surface features.
For example, a bright heart-shaped region near
Pluto’s equator has no impact craters, indicating a surface that is less than
about 100 million years old, a relative blink in geologic time.
“It’s possibly still being shaped this day by
geological processes. Those could be only a week old, for all we know,”
geologist Jeffrey Moore, with NASA’s Ames Research Center in Moffett Field,
California, told reporters on a conference call.
A section of the plain is broken into 12- to 20
mile (19- to 32-km) wide polygon shapes that are boarded by shallow troughs,
some of which are lined with dark material. Even more enigmatic are clusters of
hills, or clumps that trace the shapes of the troughs and encircle the
polygons.
“We suspect the hills may have been pushed up from
underneath along the cracks,” Moore said.
Another possibility is that the plain is eroding
around the hills, leaving behind mounds of a more resistant material.
“We don’t know which of those two explanations are
correct,” Moore said.
The polygons could be evidence of convection in
Pluto's icy face, similar to the surface of a boiling pot of oatmeal. The
source of Pluto’s internal heat, if it exists, has not yet been determined.
The polygons also could be like mud cracks, created
by contraction of the surface, Moore added.
“The landscape is just astoundingly amazing,” he
said.
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Pluto's largest moon Charon
is shown in this NASA handout image which was taken at approximately 0630 EDT
(1030 GMT) on July 14, 2015, about 1.5 hours before New Horizons' closest
approach to Pluto, from a range of 49,000 miles (79,000 kilometers) and
released on July 16,...
REUTERS/NASA-JHUAPL-SWRI/HANDOUT
VIA REUTERS
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SOURCE/LINK:
https://br.noticias.yahoo.com/pol%C3%ADgonos-encontrados-em-plut%C3%A3o-desafiam-cientistas-213551896.html
Polígonos
encontrados em Plutão desafiam cientistas
Por Por Irene
Klotz | Reuters – sex, 17 de jul de 2015
Por Irene
Klotz
NOVA YORK (Reuters) - Novas fotos
transmitidas pela primeira espaçonave a visitar Plutão mostraram estranhas
formas poligonais e colinas suaves em uma planície sem crateras, indicações de
que esse mundo gelado é geologicamente ativo, disseram cientistas do projeto
New Horizons nesta sexta-feira.
"Não tínhamos ideia de que Plutão
teria uma superfície geologicamente jovem", disse o chefe de pesquisas,
Alan Stern, do Instituto de Pesquisa do Sudeste em Boulder, Colorado. "É
uma surpresa maravilhosa."
A meta da missão New Horizons, que
custou 720 milhões de dólares, é mapear as superfícies de Plutão e sua lua
primária, Charon, avaliar quais materiais elas contêm e estudar a atmosfera do
planeta.
Lançada em 2006, a espaçonave viajou
quase 5 bilhões de quilômetros até passar pelo sistema de Plutão na
terça-feira. Apenas 1 por cento dos 50 gigabytes de dados registrados nos 10
dias que levaram à passagem do equipamento pelo planeta-anão foram transmitidas
de volta à Terra.
Mesmo assim, os primeiros resultados
mostram que Plutão, onde as temperaturas na superfície chegam a menos 240 graus
Celsius, está desafiando teorias sobre como corpos gelados podem gerar calor
para redesenhar sua aparência na superfície.
Por exemplo, uma região brilhante, em
forma de coração, perto do equador de Plutão, não tem crateras de impacto,
indicando que a superfície tem mais ou menos 100 milhões de anos de idade, um
piscar de olhos no calendário geológico.
"Está provavelmente obtendo sua
forma atualmente através de processos geológicos. Podem ter apenas uma semana
de idade, até onde sabemos", disse o geólogo Jeffrey Moore, do Centro de
Pesquisas Ames, da Nasa, em Moffett Field, Califórnia, a repórteres, durante
teleconferência.
Uma seção plana está cortada em formas
poligonais de 19 a 32 quilômetros de largura, delineadas por bordas rasas,
algumas das quais possuem material escuro. Ainda mais enigmáticas são as
cadeias de colinas ao redor dos polígonos.
"Suspeitamos que as colinas podem ter aparecido após serem
pressionadas para cima junto às divisões", disse Moore.
Outra possibilidade é de que a planície
esteja erodindo ao redor das colinas, deixando para trás montes compostos de um
material mais resistente.
"Não sabemos quais dessas duas explicações são corretas",
disse Moore.
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