APOD: Plutos Newly Discovered Moons Names... (2013 Jul 08)

[APOD Robot]

Plutos Newly Discovered Moons Receive Names

Explanation: Pluto's newly discovered moons now have names. Known previously as P4 and P5, the International Astronomical Union has now given the fourth and fifth discovered moons of Pluto the names Kerberos and Styx. The small moons were discovered in 2011 and 2012 by the Hubble Space Telescope in preparation for the close passing of the New Horizons spacecraft by Pluto in 2015. Keberos is named for the many headed dog in Greek mythology that guards the entrance to the underworld, while Styx is named for the goddess who overlooks the mythological river that runs between the Earth and the underworld. Both monikers are related to the name of Pluto, who rules the mythical nether region. Because their reflectively is unknown, the size of each moon is quite uncertain -- but each is crudely estimated to be about 20 kilometers in diameter. The robotic New Horizons spacecraft is on schedule to pass by Pluto in 2015 and provide the first clear images of the dwarf planet and its companions.

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[geckzilla]

In less than 1.5 years New Horizons will begin sending data about Pluto back to Earth. Remembering when it first launched I didn't think it could get there soon enough. But now to me it seems like not long ago it was launched. Ten years gone by... and here I can't complain too hard about getting old because I'm one of the youngest here. How frustrating!

[ta152h0]

Mr Tyson, can we get our planet back ?

[bystander]

http://asterisk.apod.com/viewtopic.php?p=202563#p202563

[DOUGLAS L. MARTIN]

REFLECTIVELY SHOULD BE REPLACED BY REFLECTIVITY IN THE DESCRIPTION.

[SLYMAN69]

Funny how there can be five moons to 'no planet'. You might want to make up your minds on this one. Is Pluto a planet with moons or not?

[Bergerac]

The Pluto-Charon association involves a binary system in which primary and secondary are locked in mutual synchronous orbit about a common center - the same side of each body faces the other perpetually. Existence of numerous moons accompanying the association clearly indicates that a binary system can remain in equilibrium while supporting an extended satellite structure. The implications are that the Pluto-Charon association can be used as a model for visualizing terrestrial binary planetary systems involving a primary and secondary locked in mutual synchronous orbit and accompanied by numerous moons. The artists fantasy depictions of numerous planetary spheres in the sky may not be such a fantasy. Extrapolating the diameter of Pluto to 10000 km, or 11000 km, what kind of a terrestrial binary system would emerge from such a hypothetical study? Both primary and secondary would have substantial atmospheres and the period of one day would be the period of revolution about the common center. Placement of such a binary planet association would probably be in the vicinity of approximately 200 million km distant from a Sun-like star. It would be beyond the habitable zone for Earth like terrestrial worlds but the dense atmosphere would make up for loss of light due to distance. Such a binary planetary association may be endowed with numerous moons or ring made up of suspended particles, or both.
Configuration of terrestrial binary systems may be based on mathematical models of the Pluto-Charon binary association.

[nstahl]

"Mythology"; an interesting word. I guess it gets used when the subscribers to the religion-become-mythology are few enough or civilized enough to not react wildly. I can't imagine getting away with a public reference to "Christian mythology" or "Muslim mythology". Maybe in five hundred years.

[BDanielMayfield]

Ah, the new “Dwarf Moons” perhaps?

http://www.skyandtelescope.com/news/Int ... 18041.html

Bruce

[neufer]

[b][color=#0000FF][size=150]Diagram of generic quasi-satellite orbit[/size][/color][/b]

---

<<(15810) 1994 JR1 is a minor planet that moves around the Sun in an orbit entirely located beyond Neptune. It is the first object that was confirmed to be a quasi-satellite of Pluto.

(15810) 1994 JR1 was discovered on May 12, 1994 by M. J. Irwin and A. Zytkow with the 2.5 m Isaac Newton Telescope at the Roque de los Muchachos Observatory in the island of La Palma. It is a plutino, so it is trapped in a 2:3 mean motion resonance with Neptune, similarly to dwarf planet Pluto (the largest known plutino). It has a perihelion (closest approach to the Sun) of 34.753 AU and an aphelion (farthest distance from the Sun) of 43.722 AU, so it is moving in a relatively eccentric orbit entirely beyond Neptune. It is about 127 km in diameter.

(15810) 1994 JR1 is currently following a quasi-satellite loop around Pluto. In contrast with the cases of 2002 VE68 or (309239) 2007 RW10, the quasi-satellite state of (15810) 1994 JR1 is mainly the result of resonances with Neptune not caused by a discrete close encounter with another body. This dynamical behavior is recurrent, the object becomes a Plutonian quasi-satellite every 2 Myr and remains in that phase for nearly 350,000 years.

(15810) 1994 JR1 is moving in a very stable orbit, likely as stable as Pluto's. This suggests that it may be a primordial plutino formed around the same time Pluto itself and Charon came into existence. It is unlikely to be relatively recent debris originated in collisions within Pluto’s system or a captured object.

(15810) 1994 JR1 is currently one of Pluto's closest neighbors. In 2017, it will be only 2.7 AU from Pluto. It is currently the best known target for a flyby by the New Horizons spacecraft after its Pluto flyby in 2015, but it is hoped that still better targets will be found by then.>>

[orin stepanek]

Funny how there can be five moons to 'no planet'. You might want to make up your minds on this one. Is Pluto a planet with moons or not?

Sigh! Pluto is considered to be a Dwarf Planet; but still a planet! Just like Jupiter is considered to be a Giant Planet!

[rstevenson]

"Mythology"; an interesting word. I guess it gets used when the subscribers to the religion-become-mythology are few enough or civilized enough to not react wildly. I can't imagine getting away with a public reference to "Christian mythology" or "Muslim mythology". Maybe in five hundred years.

We're not allowed to discuss Christian mythology or Muslim mythology here at the Asterisk. But I think I may say that I've used both those phrases verbally without getting the slightest reaction. (But there are places in the world where I wouldn't say them out loud. )

Rob

[Boomer12k]

Since another name for Pluto....in Mythology....was Hades...we should call the whole thing, "The Hades System", as the term became the name of the Underworld as a place. And since Pluto's orbit is in and out of the Kuiper Belt, it seems appropriate. It is not totally a Solar System Object, as the other planets. But travels to an "outer realm"...the Underworld...Hey, it is MYTHOLOGY!!!!! It is also akin to comets in that respect.

:---[===] *

[neufer]

"Mythology"; an interesting word. I guess it gets used when the subscribers to the religion-become-mythology are few enough or civilized enough to not react wildly. I can't imagine getting away with a public reference to "Christian mythology" or "Muslim mythology". Maybe in five hundred years.

We're not allowed to discuss Christian mythology or Muslim mythology here at the Asterisk. But I think I may say that I've used both those phrases verbally without getting the slightest reaction. (But there are places in the world where I wouldn't say them out loud. )

---

<<The ring-shaped doughnut was allegedly invented in about 1847 by a man from Camden, Maine. In The Washington Post of Mar. 26, 1916, Captain Hanson Gregory claimed to have had his brainstorm while aboard a lime-trading ship at the age of 16.

"Now in them days we used to cut the doughnuts into diamond shapes, and also into long strips, bent in half, and then twisted. I don't think we called them doughnuts then—they was just 'fried cakes' and 'twisters.'

"Well, sir, they used to fry all right around the edges, but when you had the edges done the insides was all raw dough. And the twisters used to sop up all the grease just where they bent, and they were tough on the digestion."

"Well, I says to myself, 'Why wouldn't a space inside solve the difficulty?' I thought at first I'd take one of the strips and roll it around, then I got an inspiration, a great inspiration.

"I took the cover off the ship's tin pepper box, and—I cut into the middle of that doughnut the first hole ever seen by mortal eyes!"

"Were you pleased?"

"Was Columbus pleased? Well, sir, them doughnuts was the finest I ever tasted. No more indigestion—no more greasy sinkers—but just well-done, fried-through doughnuts."

Upon returning to Camden, Gregory taught his mother the trick. She sent several panfuls to Rockland, where they were an instant hit.

A plaque near Clam Cove in the present town of Rockport marks Captain Gregory's birthplace, which is now the parsonage of the Nativity Lutheran Church. Captain Gregory lived his last years at Sailors' Snug Harbor in Quincy, Mass., and was buried there beneath a prominent headstone in 1921.>>

[Chris Peterson]

The Pluto-Charon association involves a binary system in which primary and secondary are locked in mutual synchronous orbit about a common center - the same side of each body faces the other perpetually. Existence of numerous moons accompanying the association clearly indicates that a binary system can remain in equilibrium while supporting an extended satellite structure.

This is not a particularly stable system. As a rule, the more bodies you throw into the system, the less stable it becomes.

You could certainly scale the Pluto system up to a solar system. But what you'd end up with wouldn't be something likely to exist for billions of years, allowing life (or especially, complex life) to develop.

Complex, multiple body orbits certainly exist in nature, and we will discover them in many star systems. But we will probably not discover many long lived systems like that.

[Ron-Astro Pharmacist]

Speaking about stable systems, I’ve never understood Lagrangian points. Do moons cause them or are they an interaction between then planet and the moon? Since we like to put satellites in orbit at them, it seems like a place where matter might accumulate. They seem like a very unusual place in the space around us. Ron

[neufer]

Click to play embedded YouTube video.

.

As a rule,

the more bodies you throw into the system,
the less stable it becomes.

[Beyond]

It all depends on how they're marxed.

[neufer]

Speaking about stable systems, I’ve never understood Lagrangian points. Do moons cause them or are they an interaction between then planet and the moon? Since we like to put satellites in orbit at them, it seems like a place where matter might accumulate. They seem like a very unusual place in the space around us. Ron

[b][color=#FF0000][size=150]The New Horizons Nominal Trajectory will pass close to the [/size][/color][/b][url=http://en.wikipedia.org/wiki/Hilda_family][b][color=#FF0000][size=150]unstable L3 Lagrangian point.[/size][/color][/b][/url]

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<<The Lagrangian points (also Lagrange points, L-points, or libration points) are the five positions in an orbital configuration where a small object affected only by gravity can theoretically be part of a constant-shape pattern with two larger objects (such as a satellite with respect to the Earth and Moon). The Lagrange points mark positions where the combined gravitational pull of the two large masses provides precisely the centripetal force required to orbit with them. L1, L2, and L3 positions are as stable as a ball balanced on the tip of a wedge would be stable: any disturbance will toss it out of equilibrium. The L4, and L5 positions are stable as a ball at the bottom of a bowl would be stable: small perturbations will move it out of place, but it will drift back toward the center of the bowl. The Earth–Moon L4 and L5 points lie 60° ahead of and 60° behind the Moon as it orbits the Earth. They may contain interplanetary dust in what is called Kordylewski clouds; however, the Hiten spacecraft's Munich Dust Counter (MDC) detected no increase in dust during its passes through these points.>>

<<What by the 21st century is the internationally recognized symbol for peace was originally designed in 1958 for the British nuclear disarmament movement by Gerald Holtom. Holtom, an artist and designer, made it for a march from Trafalgar Square, London to the Atomic Weapons Research Establishment at Aldermaston in England.

The symbol is a combination of the semaphore signals for the letters "N" and "D," standing for "nuclear disarmament". In semaphore the letter "N" is formed by a person holding two flags in an inverted "V," and the letter "D" is formed by holding one flag pointed straight up and the other pointed straight down. Superimposing these two signs forms the shape of the centre of the peace symbol. Holtom later wrote to Hugh Brock, editor of Peace News, explaining the genesis of his idea in greater depth:

"I was in despair. Deep despair. I drew myself: the representative of an individual in despair, with hands palm outstretched outwards and downwards in the manner of Goya's peasant before the firing squad. I formalised the drawing into a line and put a circle round it".

Ken Kolsbun, a correspondent of Holtom's, says that the designer came to regret the symbolism of despair, as he felt that peace was something to be celebrated and wanted the symbol to be inverted. Eric Austen is said to have "discovered that the 'gesture of despair' motif had long been associated with 'the death of man', and the circle with 'the unborn child'." Some time later, Peggy Duff, general secretary of CND between 1958 and 1967, repeated this interpretation in an interview with a US newspaper, saying that the inside of the symbol was a "runic symbol for death of man" and the circle the "symbol for the unborn child".

Ken Kolsbun in his "biography" of the peace symbol wrote that, "In an attempt to discredit the burgeoning anti-war movement, the John Birch Society published an attack on the peace symbol in its June 1970 issue of American Opinion", calling the symbol "a manifestation of a witch's foot or crow's foot", supposedly icons of the devil in the Middle Ages. A national Republican newsletter was reported to have "noted an ominous similarity to a symbol used by the Nazis in World War II".>>

Art NeuenDorffer

[ta152h0]

getting dangerous to fly thru that system. There are no brakes on New Horizons, right ?

[neufer]

getting dangerous to fly thru that system. There are no brakes on New Horizons, right ?

They did provide it with a loud horn however.

[ta152h0]

too bad only one went on the epic trip. Something changed since the decision to build Viking 1 and Viking 2

[Ron-Astro Pharmacist]

Very Interesting!! Thanks. I was recently watching a program and they refered to the "Nuker Team" Of course I mis-heard them and thought I had a scoop about Art's past history. Too bad!! It wouldn't have surprised me.

http://www.noao.edu/noao/staff/lauer/nuker.html

[neufer]

too bad only one went on the epic trip. Something changed since the decision to build Viking 1 and Viking 2

There is a big difference between an orbiter or flyby mission and a lander like Viking or MER:

Landers are predetermined to get independent measurements from independent landing sites.

A duplicate orbiter or flyby mission is basically only an insurance policy.

[bystander]

getting dangerous to fly thru that system.

http://asterisk.apod.com/viewtopic.php?p=201479#p201479