Astronomers get rare glimpse of icy, dwarf planet

By AFP

Image: Standret via Shutterstock

21/11/12 10,958 Views 17 Comments

A RARE DALLIANCE with a star in a remote part of our Solar System has allowed scientists to glean data on a distant, icy dwarf planet about which we knew very little before, astronomers said Wednesday.

They had expected to find an atmosphere similar to that of Pluto on the planet named Makemake but instead saw “no sign of one at all”, the group wrote in the journal Nature.

They also discovered that Makemake, one of five dwarf planets known to exist on the edge of our Solar System, reflected more light from the Sun than its near neighbour Pluto.

Makemake reflected 77 percent of the Sun’s light compared to Pluto’s 52 percent — akin to the reflective power of dirty snow, the team reported.

Makemake is about two-thirds the size of Pluto and orbits at a distance of about 7.8 billion kilometres from the sun — somewhere between Pluto and Eris, the biggest and most distant of the known dwarf planets.

Previous observations had shown Makemake to be similar to its fellow dwarfs in many ways, leading some to expect that its atmosphere would resemble Pluto’s, said a statement issued by the team led by Jose Luis Ortiz of the Instituto de Astrofisica de Andalucia in Spain.

To make its observations, the team had to wait until Makemake passed in front of a distant star, which happened on April 23, 2011, and then trained seven telescopes in Brazil and Chile on the mysterious body.

“As Makemake passed in front of the star and blocked it out, the star disappeared and reappeared very abruptly, rather than fading and brightening gradually,” said Ortiz.

“This means that the little dwarf planet has no significant atmosphere.”

Makemake’s lack of moons and its great distance from us make it difficult to study.

But with their new observations, the team was able to glean new data about the planet’s size and density.

The concluded it is a sphere slightly flattened at the poles — its polar equatorial axis about 1,430 kilometres.

“Makemake was the poorest-known dwarf planet and thanks to our study we have revealed several important properties of this body,” Ortiz told AFP.

The opportunity was a rare one, as Makemake moves in an area of the sky with relatively few stars, said the statement.

The planet was initially nicknamed Easterbunny, having been discovered a few days after Easter in March 2005.

It was officially christened in July 2008 — named for the creator of humanity and god of fertility in the myths of Eastern Island.

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Comments (8 Comments)
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Eamon O'Gorman 21/11/12 Comment reported, thank you Report this comment
Yep both Pluto and Makemaker are dwarf-planets and not planets

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  Alan Little 21/11/12 Comment reported, thank you Report this comment
  Cool spaceman suit dude!
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  Cornelius Crow 21/11/12 Comment reported, thank you Report this comment
  random
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Alan Little 21/11/12 Comment reported, thank you Report this comment
I too thought they decided Pluto was too Mickey Mousey to be a planet.

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tom 21/11/12 Comment reported, thank you Report this comment
was Pluto not declassified as a planet ?

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Mick Jordan 22/11/12 Comment reported, thank you Report this comment
To think 100 years ago if you told someone that men would go into space on a regular basis, that you could talk to someone on the side of the world face to face on a device a few inches square, that man would see a star being born and another dying they would have locked you up in an asylum. In another 200 years the idea people might be going on holiday cruises to the outer parts of our solar system is not as far fetched as it once would have been.
Every day we are discovering new wonders in the universe.

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Éamonn 21/11/12 Comment reported, thank you Report this comment
Any guesses as to the pronunciation of the damned thing?

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  Adrian Horsman 21/11/12 Comment reported, thank you Report this comment
  I’m going with “macky-macky” because that sounds more Easter Islandish. I think.
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Diarmuid Kennan 21/11/12 Comment reported, thank you Report this comment
a star in a remote part of our solar system? I don’t think so.

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  Barry O'Brien 21/11/12 Comment reported, thank you Report this comment
  That was my first thought too, but after reading the whole article it explains that the observation of the planet (in our solar system) passed on front of a distant star. The confusion is because of the word ‘dalliance’ I assume.
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  Barry O'Brien 21/11/12 Comment reported, thank you Report this comment
  That was my first though too, but after reading the whole article it explains that the observation of the planet (in our solar system) passed on front of a distant star. The confusion is because of the word ‘dalliance’ I assume.
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  Paulie Sullivan 21/11/12 Comment reported, thank you Report this comment
  Yeah that doesn’t make sense. There’s only one star in our solar system; the sun. Maybe you mean galaxy?
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Mike Clinton 21/11/12 Comment reported, thank you Report this comment
Meanwhile on the forest moon Darth Vadar was caught interfeering with an Ewok as Luke Skywalker and the alliance were setting up growhouses.

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  Graham Kiely 21/11/12 Comment reported, thank you Report this comment
  Mike, I’ve yet to come across a comment by you that had more green than red thumbs……..and rightly so.
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  Mike Clinton 21/11/12 Comment reported, thank you Report this comment
  There are a few. Thanks for caring though.
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Caroline Locke 21/11/12 Comment reported, thank you Report this comment
WOW.

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  Caroline Locke 21/11/12 Comment reported, thank you Report this comment
  I will elaborate:Nothing short of amazing here.