[HSMW]

Novas imagens de Plutão e algo estranho no hemisfério Sul.
E eu a pensar que seria um planeta cinzento sem grande interesse...

[Lusitano89]

Novas imagens de Plutão e algo estranho no hemisfério Sul.
E eu a pensar que seria um planeta cinzento sem grande interesse...

Podem parecer insignificantes, mas tem se revelado uma caixinha de surpresas  

[Lusitano89]

Siga em direto milhares de objetos que estão na órbita terrestre com este mapa 3D

   http://stuffin.space/

Entre lixo e satélites, há mais de 150 mil "coisas" a orbitar o planeta Terra. Um jovem de 18 anos criou uma plataforma em que é possível acompanhá-las a partir de casa.

Quando olha para o céu de noite e só vê escuridão ou estrelas, já parou para imaginar o que mais está lá em cima? James Yoder construiu uma plataforma em que é possível ter uma imagem mais clara da quantidade de destroços e satélites e outros objetos que estão na órbita terrestre: com o Stuff in Space (Coisas no Espaço), pode ver-se em tempo real onde estão os objetos que rodeiam o planeta.

No site do projeto, é possível pesquisar satélites pelo nome para ver onde se encontram, e mesmo saber a idade e altitude dos objetos.

James Yoder, de 18 anos, baseou-se no site Space Track, que pertence ao Departamento da Defesa dos Estados Unidos e que mostra onde se encontram os objetos que rodeiam a Terra cujo tamanho é maior do que o de um punho fechado.

O Stuff in Space atualiza-se automaticamente a partir dos dados do Space Track, prevê onde vão estar os objetos que rodeiam a Terra ao longo do dia, e vai atualizando as suas posições, sendo possível acompanhar em direto o seu movimento.

"Com os parâmetros orbitais do Space Track, o stuffin.space usa um modelo de propagação para prever a localização de cada satélite em tempo real", explicou, num e-mail ao site especializado Gizmodo, o jovem James Yoder. "Depois mostra os dados com uma imagem correta da rotação da Terra e do ângulo do Sol".

James Yoder vai entrar este ano na Universidade, conta o Gizmodo, em Austin, no estado do Texas. Começou o Stuff in Space para se entreter, em abril.

DN

[HSMW]

Siga em direto milhares de objetos que estão na órbita terrestre com este mapa 3D

 :shock:  
Isso tudo reciclado até deve render uns trocos.

[Lusitano89]

[HSMW]

Ah Lusitano... Foste mais rápido que eu!  

Excelente vídeo.

[HSMW]

A missão Mariner 4

[HSMW]

Três mistérios em Plutão.
Chegada da sonda no dia 14.

[HSMW]

 

[Lusitano89]

[mafets]

http://www.space.com/29924-pluto-larger-than-thought-nasa-flyby.html

LAUREL, Md. — With less than 24 hours to go before NASA's New Horizons probe makes its close flyby of Pluto, scientists are already learning more about the dwarf planet than ever before, including the fact that it is bigger than previously thought.

New Horizons' latest views of Pluto have shown the dwarf planet to be 1,473 miles (2,370 kilometers) across, making it the largest body in the icy Kuiper Belt at the edge of the solar system. The observations also confirmed the presence of a polar ice cap on Pluto, and measured three of the dwarf planet's moons.

"Pluto is not disappointing," said principal investigator Alan Stern, of the Southwest Research Institute in Boulder, Colorado, during a NASA briefing here today (July 13).

As New Horizons closes in, the spacecraft made the most precise measurements to date of Pluto's size using methods similar to those employed by NASA's Voyager spacecraft. The new diameter of the dwarf planet makes it larger than fellow Kuiper Belt denizen Eris, which is 1,445 miles (2,326 km) in diameter.

Previous estimates for the size of Pluto had put its radius at 1,430 miles (2,301 km). But Pluto now stands as the undisputed king of the Kuiper Belt.

"This settles the debate about the largest object in the Kuiper Belt," Stern said.

With Pluto's mass already known, the larger radius means that the dwarf planet is less dense than previously estimated, suggesting the possibility of an icier interior, though Stern stressed this was still under investigation.

In addition to refining Pluto's size, New Horizons also measured three of the dwarf planet's five known moons. The spacecraft's observations of Charon, the largest, confirm measurements made from Earth of 751 miles (1,208 km). Nix is about 20 miles (35 km) wide, while Hydra turns out to be approximately 30 miles (45 km) in diameter.

Resta saber se passa novamente a Planeta ou continua como Planetóide (o que foi feito à cerca de 9 anos) http://www.brasilescola.com/geografia/plutao-rebaixado.htm



Saudações

[HSMW]

E antes de Julho 2015 era assim:

[HSMW]

[Lusitano89]

[mafets]

http://www.theguardian.com/science/2015/jul/15/pluto-planet-status-debate-dwarf?CMP=fb_gu

Pluto lost its title as our ninth planet nearly a decade ago, not long after Nasa launched a 3bn-mile mission to the celestial body that reached its destination this week, and not nearly enough time for passions to cool over its demotion.

Nasa’s historic New Horizons mission to Pluto has revived those passions, if not the official debate, between scientists who can’t agree about the definition of a planet. In 2006 the International Astronomical Union took up the question, and a handful of voters decided the issue. Pluto was reclassified from one of the nine planets to a new category, the dwarf planet, based on its size and the discovery of similar bodies in its neighborhood that Pluto’s gravity does not dominate.

Scientists dissented. Citizens protested. Somebody sold “save Pluto” merchandise. But the question persists: what is a planet? Luminaries including astrophysicist Neil deGrasse Tyson have sided against Plutonian planethood, with Tyson telling Stephen Colbert that to call Pluto a planet “would insult all the other planets”.

On the other side of the ring is New Horizons lead scientist Alan Stern, who said in 2011 the IAU had “embarrassed” itself and that under the definition used Earth would sometimes not be a planet.

“Any definition that produces a result where Earth is not a planet under any circumstance is immediately indicted as ridiculous, because one thing we all agree is a planet is planet Earth!”

Some of his colleagues agree, though they doubt the IAU will reconsider its position.

“I don’t expect the IAU to reverse what they’ve done, but I do expect it to be widely ignored,” said David Grinspoon, a Nasa planetary scientist on the New Horizons mission.

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“A lot of planetary scientists don’t take the supposed demotion of Pluto that seriously,” he said. “I’m in that camp. I’ve always considered it a planet.”

Grinspoon conceded that Pluto “needed to be reclassified” and that he’s “happy with pointing out that it’s a different kind of planet”, but said that planetary specialists often don’t see eye to eye with astronomers about the title.

“Planetary scientists think about planets as bodies with processes and systems, and a lot of astronomers mostly think of them as objects orbiting around other objects. But people will keep referring to Pluto as a planet because it is one.

“To me its intrinsic, geophysical properties are more significant – for instance if it’s large enough to be round by self-gravity, and orbiting the sun or a star, then we might consider it a planet.”

But such definitions could add anywhere from three to a dozen more planets to the solar system, said Harvard astronomer Gareth Williams. “If you look at the outer solar system there are a lot of Pluto-size bodies in orbit near Pluto,” Williams said.

“We could’ve immediately looked at it and come up with 12 or 13 objects that could be treated as planets, and within a decade we could have 50 or 100 objects.”

Those objects include Eris, whose 2005 discovery helped provoke the IAU debate. Larger than Pluto, Eris orbits in the solar system’s outer fringe called the Kuiper belt, where ancient fragments of ice and rock drift through the dark.

The man who discovered Eris, astronomer Mike Brown, told National Geographic last year that the question came down to orbits: “Why has the solar system sorted itself into a small number of dominant bodies and a huge number of tiny ones flitting between them? This is the sort of question scientists are actively trying to answer.”

Brown, who calls himself “the Pluto Killer”, tweeted on Wednesday: “Sure, it’s OK to grandfather Pluto in as a planet. Also you can grandfather the Earth as flat, too, if that makes you feel better.”

“Pluto should never have been a planet in the first place,” Williams said, saying that errors in its discovery had mischaracterized it from the start. “You’re simply moving it from the smallest of planets to the king of the Kuiper belt.”

UCLA professor Jean-Luc Margot agreed. “The New Horizons discoveries are very exciting but they will not change the definition of a planet. It’s a beautiful definition and it makes sense.”

Margot said the definition worked because it relied on dynamics and dominance: “A planet has to be able to clear its orbital zone” – be the dominant player in its neighborhood – “and if you look at that aspect in the solar system there are eight bodies that can very clearly do that. There’s a very, very sharp distinction between the eight bodies and Pluto.”

Definitions about roundness or composition would require close inspection of everything in space, he said, while the current definition could be adjusted to include planets outside the solar system.

Other scientists feel the IAU took on something of a fool’s errand. Astronomer Owen Gingerich told a Harvard symposium last year that ultimately “it’s a culturally defined word” whose meaning has shifted over centuries, as all language does.

“I thought it was really dumb that the IAU took as a category ‘dwarf planet’ and then said: ‘But they’re not planets,’” he said. “I think this is an abuse of the language.”

Grinspoon agreed: “The strange linguistic trick of saying it is ‘a dwarf planet and a dwarf planet is not a planet’, that just seemed vindictive.”

He also observed that almost everyone, astronomers and planetary scientists alike, realized that their “strong feelings” paled next to their excitement about the mission.

“There’s a lot of people who don’t care,” he said. “They’re probably the wisest among us.”

A close-up image of a region near Pluto’s equator which reveals a range of youthful mountains rising as high as 11,000 ft (3,500 metres) above its surface. Photograph: Nasa handout/EPA

Pluto’s moon Charon.

Cumprimentos