Pluto | Universe Today

New Horizons got a great shot of Neptune's moon Triton last fall, as it was trucking toward Pluto and the Kuiper Belt. 

The mission was 2.33 billion miles (3.75 billion kilometers) from Neptune on Oct. 16, when its Long Range Reconnaissance Imager (LORRI) locked onto the planet and snapped away. The craft was following a programmed sequence of commands as part of its annual checkout. NASA released the image Thursday afternoon.

Mission scientists say the shot was good practice for imaging Pluto, which New Horizons will do in 2015. Neptune's moon Triton and Pluto — the former planet retitled in 2006 as the ambassador to the Kuiper Belt — have much in common.

“Among the objects visited by spacecraft so far, Triton is by far the best analog of Pluto,” said New Horizons Principal Investigator Alan Stern. 

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Filed under: Missions, NASA, Neptune, Pluto | 9 Comments »

Pluto is certainly frigid, but new research has revealed its atmosphere is a bit warmer.

Astronomers using the European Southern Observatory's Very Large Telescope have found unexpectedly large amounts of methane in Pluto's atmosphere, which evidently helps it stay about 40 degrees warmer than the dwarf planet's surface. The atmosphere warms to -180 degrees Celsius (-356 degrees Fahrenheit), compared to a surface that's usually -220 degrees Celsius (-428 degrees Fahrenheit).

“With lots of methane in the atmosphere, it becomes clear why Pluto’s atmosphere is so warm,” said Emmanuel Lellouch of the Observatoire de Paris in France. Lellouch is lead author of the paper reporting the results, which is in press at the journal Astronomy and Astrophysics.

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Filed under: Pluto, Solar System | 25 Comments »

Naming Pluto promotional poster (© Father Films)

In recent years, Pluto has seen its status change from being a planet to what many people view as a planetary underclass. The reasons behind this have been set out by the International Astronomical Union (IAU) to cater for the increasing number of Solar System bodies being discovered; the traditional nine planets have had to make room for a growing minor planet population. Unfortunately, Pluto was at the front line as it inhabits a region of space dominated by the gas giant Neptune, plus thousands of other Kuiper belt objects. Although the mysterious body lost its planetary status (as it does not have the ability to "clear its own orbit"), it has taken the title of "dwarf planet" and now has an entire class of object named in its honour: "Plutoids".

However, the recent tumultuous history of the traditional "9th planet" has not impacted the fascination we have for Pluto. It has, and always will be, viewed with intrigue and wonder.

The key to Pluto's romantic tale begins in the year 1930 when a mysterious heavenly was discovered by Clyde Tombaugh, a 23 year-old astronomer working at the Lowell Observatory in Flagstaff, Arizona. However, the honour of naming Pluto didn't rest on Tombaugh's shoulders. Over 5000 miles away in Oxford (UK) an 11 year old girl was having breakfast with her grandfather, wondering what this newly discovered planet should be called…
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Eris, the largest dwarf planet beyond Neptune, is currently at its furthest point in its orbit from the Sun (an aphelion of nearly 100 AU). At this distance Eris doesn't receive very much sunlight and any heating of the Plutoid will be at a minimum. However, two recent observations of Eris have shown a rapid change in the surface composition of the body. Spectroscopic analysis suggests the concentration of frozen nitrogen has dramatically altered during the two years Eris had been at this furthest point from the Sun. This is very unexpected, there should be very little change in nitrogen concentration at this point in its 557 year orbit.

So what is going on with this strange Plutoid? Is there a mystery mechanism affecting the surface conditions of this frozen moon? Could there be some cryovolcanic process erupting? Or is the explanation a little more mundane?
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Filed under: Planetary Formation, Pluto, Solar System | 18 Comments »

This past summer, a group of seven amateur astronomers from Italy worked on an observation campaign of Pluto, with hopes of capturing an image of its moon, Charon. "Imaging Charon is very difficult and nobody has spotted it with amateur equipment, so far," said Daniele Gasparri, one of the members of the group. The team made several attempts, and finally, one member of the group, Antonello Medugno, took this interesting image. "After many calculations," said Gasparri, "we are sure that this image shows clearly Pluto and Charon, for the first time with amateur equipment." Comparing the image to the graphic which shows the position of Pluto and Charon on the same date, it's obvious, they nailed it! This is quite a feat considering their equipment was an "amateur" 14-inch telescope! Also, as The Bad Astronomers points out, Charon wasn't discovered until 1978, and then a 61-inch telescope was used!

Compare their image to one taken by Hubble:
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Filed under: Astronomy, Pluto | 12 Comments »

This object is a stowaway on board New Horizons. Credit: JHU/APL

The New Horizons spacecraft has now spent over 1,000 days wending its way to Pluto and the Kuiper Belt. To celebrate the milestone, the New Horizons team decided to reveal the secret stowaways on board the spacecraft. Nine objects (can you guess why there are nine?!) were attached and sent along on the ten-year journey to the outer reaches of our solar system. Believe it or not, included in the items are one actual person, and parts of several thousands of other people…
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Filed under: Missions, Pluto | 30 Comments »

Still seven years away from its rendezvous with Pluto, the New Horizons spacecraft was awoken from hibernation for the second annual checkout of all systems. The spacecraft and its team back on Earth will also undergo three months of operations as the New Horizons will make observations of Uranus, Neptune, and Pluto. But the first order of business was uploading an upgraded version of the software that runs the spacecraft’s Command and Data Handling system. “Our ‘brain transplant’ was a success,” says New Horizons Principal Investigator Alan Stern. “The new software – which guides how New Horizons carries out commands and collects and stores data – is now on the spacecraft’s main computer and operating, over a billion miles from home!”
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Filed under: Neptune, Pluto, Uranus | 20 Comments »

A debate today between astronomer Neil deGrasse Tyson and planetary scientist Mark Sykes, moderated by NPR's Ira Flatow, addressed the issue of Pluto's planetary status. There was lots of arm-waving and finger-pointing, endless interruptions, disagreements on details big and small, and battling one-liners. The two scientists sat at a table with the moderator between them and Flatow was often obscured by Tyson and Sykes getting in each other's faces in eye-to-eye confrontation. At one point, Flatow was hit by Tyson's ebullient arm motions. Yes, it was heated. But it was fun, too. It ended up being not so much a debate between the Pluto-huggers and the Pluto-haters as a disagreement over the lexicon of astronomy and planetary science and, primarily, the definition of a planet. Pluto's planetary status was definitely not decided here, and the debate concluded with an amicable agree-to-disagree concurrence that the scientific process is an ongoing, evolving practice. But it wasn't without fireworks.
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Filed under: Pluto, Science | 24 Comments »

If you thought Pluto was going quietly and giving up its planetary status without a fight, think again. Leading astronomers have spoken out against the International Astronomical Union (IAU) decision to classify the dwarf planet as a "Plutoid," described by some critics as a "celestial underclass." The IAU decision was made after it was deemed that Pluto cannot be called a "planet." Although the spherical rocky body can tick most attributes of being a "planet," the IAU pointed out that Pluto is too small to be capable of gravitationally clearing its own orbit (plus it periodically crosses the path of Neptune's orbit); it should therefore be called a "dwarf planet." Back in June however, the IAU gloriously announced that Pluto should be now be re-classified as a "Plutoid" and any other Pluto-like planets should follow suit. But on Thursday, at a major conference in Maryland, leading astronomers will refute the Plutoid classification saying the IAU re-naming is confusing and unworkable…
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The Solar System's outer reaches still contain many minor planets yet to be discovered. Ever since the search for Planet X began in the early 20th Century, the possibility of a hypothetical planet orbiting the Sun beyond the Kuiper Belt has fuelled many Doomsday theories and speculation that Planet X is actually the Sun's long lost binary sibling. But why the fear about the Planet X/Doomsday combination? Surely Planet X is just an unknown, hypothetical object and nothing sinister?

Related 2012 articles:

• 2012: No Geomagnetic Reversal (posted October 3rd 2008)
• 2012: No Killer Solar Flare (posted June 21st 2008)
• 2012: Planet X Is Not Nibiru (posted June 19th 2008)
• 2012: No Planet X (posted May 25th 2008)
• No Doomsday in 2012 (posted May 19th 2008)

As I've previously discussed in "2012: No Planet X", doomsayers have linked the modern day search for Planet X, the ancient Mayan 2012 Prophecy and the Sumerian mythical planet Nibiru, culminating in bad news for December 21st 2012. However, the astronomical evidence for these links is seriously flawed.

Yesterday (Wednesday, June 18th), Japanese researchers announced news that their theoretical search for a large mass in the outer Solar System has produced results. From their calculations, there might just be a planet, possibly a bit bigger than a Plutoid but certainly smaller than Earth orbiting beyond 100 AU from the Sun. But before we get carried away, this is not Nibiru, this is not proof of the end of the world in 2012; it is a new and very exciting development in the search for minor planets beyond the Kuiper Belt…
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Filed under: 2012, Earth, Pluto | 209 Comments »

This has got to be be one of the most heartbreaking questions I get asked, "Why Isn't Pluto a Planet". And I get it a lot. I was expecting that a few years after the International Astronomical Union's controversial decision, the debate would have settled down and people would finally accept it. But no, it's still a sore point for many people – Pluto is not a planet (let that sink in). In this article, I'll explain the events that led up to the decision, the current state of planetary definition, and any hope Pluto has for the future. Let's find out why Pluto is no longer considered a planet.
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How many moons does Pluto have? The mini-moons of Pluto, Nix and Hydra, were discovered in 2005 (but named in 2006) during an observation campaign by the Hubble Space Telescope. The discovery of these mini-moons increase the number of natural satellites orbiting Pluto to three (including larger moon Charon). But where did these satellites come from? The current accepted theory on the formation on the large moon, Charon, is much like the theory supporting the creation of Earth's Moon. It is thought that a large impact between two Large Kuiper Belt Objects chipped Charon away from a proto-Pluto, putting the chunk of Pluto mass into orbit. Over the years, tidal forces slowed the pair and Charon was allowed to settle into its present-day orbit. Recent theory suggests that Nix and Hydra are a by product of this collision, merely shattered fragments of the huge impact. But there are problems with this idea. Could Nix and Hydra have come from somewhere other than the Pluto-Charon impact?
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Filed under: Physics, Pluto | 5 Comments »

It's been a long journey, 64 episodes, but now we're back where we began: Pluto. Last time we talked about how Pluto lost its planethood status, so we won't go over all that again. This time we're going to talk about Pluto, its moons, the Kuiper belt, and the other icy objects that inhabit the outer Solar System.
Click here to download the episode

Pluto and the Icy Outer Solar System – Show notes and transcript

Or subscribe to: astronomycast.com/podcast.xml with your podcatching software.

Go here if you'd like some Pluto pictures.

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It's only been a few months since the discovery of ice geysers on Saturn's moon Enceladus, and now this dynamic process is turning up all over the Solar System. Astronomers think they've found a similar phenomenon on one of the strangest places: welling up from the surface of Pluto's moon Charon.
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For those of you hoping that Pluto the dwarf planet would get its full planethood status restored again, the news isn't looking good. The most recent observations peg the newly discovered dwarf planet Eris as being 27% more massive. And if Pluto is a planet again, shouldn't the even larger Eris get to be a planet too? Should we have 8 planets, or 10 or 20? Oh, it's madness.
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Filed under: Pluto | 14 Comments »