APOD: Pluto in Enhanced Color (2015 Aug 31)

[MarkBour]

The Disney character Pluto understands how it feels to be demoted. Initially considered for a leading role, he was eventually relegated to second class status, being cast inexplicably as a pet of a mouse (!?)

On a more serious note, there's a lovely page at: http://pluto.jhuapl.edu/Participate/lea ... Atmosphere . Based on this information, I am persuaded that the nitrogen ice of Tombaugh Regio ("the dog in the dwarf") is potentially quite thick, like a major ice sheet on Earth would be, though it probably does not move glacially. Some of the mountains of Hillary Montes may be taller than what we can see, if measured from their true base which might be below thick ice. And the large crater feature mentioned above, Elliott crater, (for which a decent name might have been "the eye of Cthulhu") is interesting, because its shape may have made it a favored location for nitrogen ice condensation, and I think I can see a rather thick deposit of said ice within it, which is giving it the dark-light-dark appearance between the rim, the ice, and the crater's central peak.

We could put an end to the debate over Pluto's status by knocking it into a more elliptical orbit, so it came in close to the Sun. Based on the material there, I'm thinking it would be the comet to end all comets.

[Asterhole]

Pluto is not the ninth planet. That’s Pallas:
But as with Pluto, they were RE-classified, and are considered asteroids...especially when considering how far out of the Ecliptic Plane that it is...there are no missions that are planned to go there for this reason, as the energy required it too great.
:---[===] *

Should we call the smaller ones "half-asteroids" ?

I LIKE IT!

[Chris Peterson]

Should we call the smaller ones "half-asteroids" ?

Hemiroids?

[neufer]

Should we call the smaller ones "half-asteroids" ?

Hemiroids?

• Not to be confused with ephemeral "Themiroids" like 171 Ophelia:

<<The Themis or Themistian asteroid family is a Hirayama found in the outer portion of the asteroid belt, between the orbits of Mars and Jupiter. At a mean distance of 3.13 AU from the Sun, it is one of the more populous asteroid families. It consists of a well-defined core of larger asteroids and a surrounding region of smaller ones. This core group includes (and is named after) the asteroid 24 Themis, discovered on April 5, 1853 by Italian astronomer Annibale de Gasparis. The Themis family is one of the largest and longest-recognized dynamical families of asteroids, and is made up of C-type asteroids with a composition believed to be similar to that of carbonaceous chondrites. To date, the Themis family comprises approximately 535 known asteroids.>>

<<171 Ophelia is a large, dark ["Themiroid"] that was discovered by French astronomer Alphonse Borrelly on January 13, 1877, and named after Ophelia in Shakespeare's play Hamlet.

• Ophelia is also the name of a moon of Uranus.

A 1979 study of the Algol-like light curve produced by this asteroid concluded that it was possible to model the brightness variation by assuming a binary system with a circular orbit, a period of 13.146 hours, and an inclination of 15° to the line of sight from the Earth. Photometric observations of this asteroid at the Leura Observatory in Leura, Australia during 2006 gave a rotation period of 6.6666 ± 0.0002 hours and a brightness variation of 0.50 ± 0.02 in magnitude.>>

[Ron-Astro Pharmacist]

Should we call the smaller ones "half-asteroids" ?

Hemiroids?

• Not to be confused with ephemeral "Themiroids" like 171 Ophelia:

<<The Themis or Themistian asteroid family is a Hirayama found in the outer portion of the asteroid belt, between the orbits of Mars and Jupiter. At a mean distance of 3.13 AU from the Sun, it is one of the more populous asteroid families. It consists of a well-defined core of larger asteroids and a surrounding region of smaller ones. This core group includes (and is named after) the asteroid 24 Themis, discovered on April 5, 1853 by Italian astronomer Annibale de Gasparis. The Themis family is one of the largest and longest-recognized dynamical families of asteroids, and is made up of C-type asteroids with a composition believed to be similar to that of carbonaceous chondrites. To date, the Themis family comprises approximately 535 known asteroids.>>

<<171 Ophelia is a large, dark ["Themiroid"] that was discovered by French astronomer Alphonse Borrelly on January 13, 1877, and named after Ophelia in Shakespeare's play Hamlet.

• Ophelia is also the name of a moon of Uranus.

A 1979 study of the Algol-like light curve produced by this asteroid concluded that it was possible to model the brightness variation by assuming a binary system with a circular orbit, a period of 13.146 hours, and an inclination of 15° to the line of sight from the Earth. Photometric observations of this asteroid at the Leura Observatory in Leura, Australia during 2006 gave a rotation period of 6.6666 ± 0.0002 hours and a brightness variation of 0.50 ± 0.02 in magnitude.>>

Ah ha. Now I know where Them came from.

It wasn't the radiation after all.

[Ron-Astro Pharmacist]

Would it be interesting to see a rotating Pluto?

Click to play embedded YouTube video.

[neufer]

Should we call the smaller ones "half-asteroids" ?

Hemiroids?

• Not to be confused with ephemeral "Themiroids" like 171 Ophelia.

Ah ha. Now I know where Them came from.

It wasn't the radiation after all.

• And Them were, in fact, immune to cyanogen/cyanide gas!

Them! (1954) Goofs: <<The ants are destroyed in the original nest using cyanide (HCN) gas. HCN works by attacking hemoglobin and changing it into cyanohemaglobin, which holds tightly to oxygen and won't release it to tissues. [However,] insects have no hemoglobin, so they would be immune to HCN.>>

<<The 1910 approach [of Halley's Comet] was notable for several reasons: it was the first approach of which photographs exist, and the first for which spectroscopic data were obtained. Furthermore, the comet made a relatively close approach of 0.15 AU, making it a spectacular sight. Indeed, on 19 May, Earth actually passed through the tail of the comet. One of the substances discovered in the tail by spectroscopic analysis was the toxic gas cyanogen [(CN)₂], Like other inorganic cyanides, cyanogen is very toxic, as it readily undergoes reduction to cyanide, which poisons the cytochrome c oxidase complex, thus interrupting the mitochondrial electron transfer chain. Astronomer Camille Flammarion to claim that, when Earth passed through the tail, the gas "would impregnate the atmosphere and possibly snuff out all life on the planet." His pronouncement led to panicked buying of gas masks and quack "anti-comet pills" and "anti-comet umbrellas" by the public. In reality, as other astronomers were quick to point out, the gas is so diffuse that the world suffered no ill effects from the passage through the tail.

The comet added to the unrest in China on the eve of Xinhai Revolution that would end the last dynasty in 1911. As James Hutson, a missionary in Sichuan Province at the time, recorded,

• "The people believe that it indicates calamity such as war, fire, pestilence, and a change of dynasty. In some places on certain days the doors were unopened for half a day, no water was carried and many did not even drink water as it was rumoured that pestilential vapour was being poured down upon the earth from the comet."

The comet was also fertile ground for hoaxes. One that reached major newspapers claimed that the Sacred Followers, a supposed Oklahoma religious group, attempted to sacrifice a virgin to ward off the impending disaster, but were stopped by the police.>>

[Charles Astro]

Does anyone have an idea on how the spiral structures inside many of the craters formed? Like the larger crater at about 7:45. If you zoom-in there are like structures in some of the smaller ones too. I don't recall seeing that in craters elswhere.

A few of Pluto's craters seem to have been flooded with ice. The one you you are talking about, called Elliot Crater by the New Horizons team, appears to have a ringed structure. At the location of the crater the sun is at a low angle so the steepest slopes facing the sun catch it brightly. The outermost bright ring is the sun shining inside the crater's steep outer rim. This ring only goes half way around and the opposite side is in shadow. The next, somewhat wider, ring is ice that has flooded the bottom of the crater, probably the same ice as fills Sputnik Planum. This bright ring is interrupted by on the sunward side by the shadow of the crater rim. At the center, the crater's central peak appears to have a snow cap, although this is also probably simply due to the fact that the sunward face of the peak is also brightly illuminated due to the low sun angle.

--------------------------
My Pluto Geology Interpretation Blog
http://charlesastro.wordpress.com

[neufer]

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I'm so happy that we've been able to see how Pluto truly looks! I hope we get to see closeup images of Nix and Hydra and its other recently discovered moons.

[starsurfer]

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I'm so happy that we've been able to see how Pluto truly looks! I hope we get to see closeup images of Nix and Hydra and its other recently discovered moons.

Thanks for that Mister neufer dude! They look wonderful, I like Nix more than Hydra.