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RE: Pluto
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News of the discovery of Pluto by the Lowell Observatory was telegraphed to the Harvard College Observatory on March 13, 1930.
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Pluto-Charon system
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Title: Dynamical capture in the Pluto-Charon system
Authors: P. M. Pires dos Santos, A. Morbidelli, D. Nesvornı

This paper explores the possibility that the progenitors of the small satellites of Pluto got captured in the Pluto-Charon system from the massive heliocentric planetesimal disk in which Pluto was originally embedded into. We find that, if the dynamical excitation of the disk is small, temporary capture in the Pluto-Charon system can occur with non-negligible probability, due to the dynamical perturbations exerted by the binary nature of the Pluto-Charon pair. However, the captured objects remain on very elliptic orbits and the typical capture time is only 100 years. In order to explain the origin of the small satellites of Pluto, we conjecture that some of these objects got disrupted during their Pluto-bound phase by a collision with a planetesimal of the disk. This could have generated a debris disk, which damped under internal collisional evolution, until turning itself into an accretional disk that could form small satellites on circular orbits, co-planar with Charon. Unfortunately, we find that objects large enough to carry a sufficient amount of mass to generate the small satellites of Pluto have collisional lifetimes orders of magnitude longer than the capture time. Thus, this scenario cannot explain the origin of the small satellites of Pluto, which remains elusive.

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Pluto and Charon
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Sharpest-ever Ground-based Images of Pluto and Charon: Proves a Powerful Tool for Exoplanet Discoveries

Despite being infamously demoted from its status as a major planet, Pluto (and its largest companion Charon) recently posed as a surrogate extrasolar planetary system to help astronomers produce exceptionally high-resolution images with the Gemini North 8-meter telescope. Using a method called reconstructive speckle imaging, the researchers took the sharpest ground-based snapshots ever obtained of Pluto and Charon in visible light, which hint at the exoplanet verification power of a large state-of-the-art telescope when combined with speckle imaging techniques. The data also verified and refined previous orbital characteristics for Pluto and Charon while revealing the pair's precise diameters.
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RE: Pluto
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The International Astronomical Union demoted Pluto to a dwarf planet in 2006.

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 Lonely outpost Pluto may hold implications for planetary systems

Pluto and its newest moons may tell us a lot about how other worlds orbit distant stars.
A new computer simulation based on the motions of Pluto's satellites not only zeroes in on the masses of two of the moons but predicts that planets orbiting double stars are more widely spaced from one another than are the worlds of single stars such as the sun.
Astronomers Andrew Youdin, Kaitlin Kratter and Scott Kenyon of the Harvard-Smithsonian Centre for Astrophysics in Cambridge, Mass., have analysed Pluto's newest moon, which does not yet have a permanent name. It's the smallest of the bunch and moves between the orbits of Nix and Hydra.

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Pluto was officially named on March 24, 1930. Each member of the Lowell Observatory was allowed to vote on a short-list of three: Minerva (which was already the name for an asteroid), Cronus (which had lost reputation through being proposed by the unpopular astronomer Thomas Jefferson Jackson See), and Pluto. Pluto received every vote. The name was announced on May 1, 1930. Upon the announcement, Madan gave Venetia five pounds (£5) (£234 as of 2012), as a reward. 
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SwRI researchers discover new evidence for complex molecules on Pluto's surface

The new and highly sensitive Cosmic Origins Spectrograph aboard the Hubble Space Telescope has discovered a strong ultraviolet-wavelength absorber on Pluto's surface, providing new evidence that points to the possibility of complex hydrocarbon and/or nitrile molecules lying on the surface, according to a paper recently published in the Astronomical Journal by researchers from Southwest Research Institute and Nebraska Wesleyan University.
Such chemical species can be produced by the interaction of sunlight or cosmic rays with Pluto's known surface ices, including methane, carbon monoxide and nitrogen.

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Title: Thermally driven escape from Pluto's atmosphere: A combined fluid/kinetic model
Authors: O. J. Tucker, J. T. Erwin, J. I. Deighan, A. N. Volkov, R. E. Johnson

A combined fluid/kinetic model is developed to calculate thermally driven escape of N2 from Pluto's atmosphere for two solar heating conditions: no heating above 1450 km and solar minimum heating conditions. In the combined model, one-dimensional fluid equations are applied for the dense part of the atmosphere, while the exobase region is described by a kinetic model and calculated by the direct simulation Monte Carlo method. Fluid and kinetic parts of the model are iteratively solved in order to maintain constant total mass and energy fluxes through the simulation region. Although the atmosphere was found to be highly extended, with an exobase altitude at ~6000 km at solar minimum, the outflow remained subsonic and the escape rate was within a factor of two of the Jeans rate for the exobase temperatures determined. This picture is drastically different from recent predictions obtained solely using a fluid model which, in itself, requires assumptions about atmospheric density, flow velocity and energy flux carried away by escaping molecules at infinity. Gas temperature, density, velocity and heat flux versus radial distance are consistent between the hydrodynamic and kinetic model up to the exobase, only when the energy flux across the lower boundary and escape rate used to solve the hydrodynamic equations is obtained from the kinetic model. This limits the applicability of fluid models to atmospheric escape problems. Finally, the recent discovery of CO at high altitudes, the effect of Charon and the conditions at the New Horizon encounter are briefly considered.

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Pluto's icy exterior may conceal an ocean

Temperatures on Pluto's surface hover around -230 °C, but researchers have long wondered whether the dwarf planet might boast enough internal heat to sustain a liquid ocean under its icy exterior.
Now Guillaume Robuchon and Francis Nimmo at the University of California, Santa Cruz, say there is a good chance it does. They calculate that an ocean depends on two things: the amount of radioactive potassium in Pluto's rocky core, and the sloshiness of the ice that covers it.

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Pluto sub-surface ocean
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Title: Thermal evolution of Pluto and implications for surface tectonics and a sub-surface ocean
Authors: Guillaume Robuchon, Francis Nimmo

Determining whether or not Pluto possesses, or once possessed, a subsurface ocean is crucial to understanding its astrobiological potential. In this study we use a 3D convection model to investigate Pluto's thermal and spin evolution, and the present-day observational consequences of different evolutionary pathways. We test the sensitivity of our model results to different initial temperature profiles, initial spin periods, silicate potassium concentrations and ice reference viscosities. The ice reference viscosity is the primary factor controlling whether or not an ocean develops and whether that ocean survives to the present day. In most of our models present-day Pluto consists of a convective ice shell without an ocean. However if the reference viscosity is higher than 5 x 10^15 Pa s, the shell will be conductive and an ocean should be present. For the nominal potassium concentration the present-day ocean and conductive shell thickness are both about 165 km; in conductive cases an ocean will be present unless the potassium content of the silicate mantle is less than 10% of its nominal value. If Pluto never developed an ocean, predominantly extensional surface tectonics should result, and a fossil rotational bulge will be present if convection is not too vigorous. For the cases which possess, or once possessed, an ocean, no fossil bulge should exist. A present-day ocean implies that compressional surface stresses should dominate, perhaps with minor recent extension. An ocean that formed and then re-froze should result in a roughly equal balance between (older) compressional and (younger) extensional features. These predictions may be tested by the New Horizons mission.

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