Pluton

In geology, a pluton is a body of intrusive igneous rock (called a plutonic rock) that is crystallized from magma slowly cooling below the surface of the Earth. Plutons include batholiths, stocks, dikes, sills, laccoliths, lopoliths, and other igneous bodies. In practice, "pluton" usually refers to a distinctive mass of igneous rock, typically several kilometers in dimension, without a tabular shape like those of dikes and sills. Batholiths commonly are aggregations of plutons. Examples of plutons include Cuillin, Cardinal Peak, Mount Kinabalu and Stone Mountain.

The most common rock types in plutons are granite, granodiorite, tonalite, monzonite, and quartz diorite. Generally light colored, coarse-grained plutons of these compositions are referred to as granitoids.

Etymology

The term originated from Pluto, the classical god of the underworld. The use of the name and concept goes back to the beginnings of the science of geology in the late 18th century and the then hotly debated theories of plutonism (or vulcanism), and neptunism regarding the origin of basalt.

Pluton (complex)

Coordinates: 45°10′13.18″N 33°15′11.18″E / 45.1703278°N 33.2531056°E / 45.1703278; 33.2531056

Pluton (at 1980ss – Pluton-M) is a system of deep space communications and planetary radar. It was built in Deep-Space Communication Center (real name "85 радиотехнический центр дальней связи с космическими объектами" - "Eighty-fifth Radiotechnical Center of Distance Communications with Space Objects") near Yevpatoria in 1960, and consists of at least three antennas. Three of them are of the ADU-1000 design, an assembly of eight reflector antennas, each with diameter of 16 metres. At the North station, two receiving antennas were built, and a transmitter was constructed 8.5 kilometres away at the South station.

Each receiving dish has a Cassegrain system with subreflectors mounted on quadrapods in front of the dishes. The dishes were placed on two hull of diesel submarines, welded together and laid down on the railway bridge trusses. The antennas of ADU-1000 were mounted on steerable frames constructed from battleship gun turrets and railway bridge trusses.

Plutoid

A plutoid or ice dwarf is a trans-Neptunian dwarf planet, i.e. a body orbiting beyond Neptune that is massive enough to be rounded in shape. The term plutoid was adopted by the International Astronomical Union (IAU) working group Committee on Small Bodies Nomenclature, but was rejected by the IAU working group Planetary System Nomenclature. The term plutoid is not widely used by astronomers, though ice dwarf is not uncommon.

There are thought to be thousands of plutoids in the Solar System, although only four have been formally designated as such by the IAU.

The IAU developed this category of astronomical objects as a consequence of its 2006 resolution defining the word "planet". The IAU's formal definition of "plutoid", announced 11 June 2008, is:

In light of the difficulty of remotely ascertaining hydrostasis, the IAU only formally confers "dwarf planet" (and by extension, "plutoid") status to those bodies whose minimum estimated size is substantially greater than what is generally thought necessary to guarantee hydrostatic equilibrium. As of 2009, Pluto, Eris, Haumea, and Makemake are the only objects officially recognized as plutoids, while upwards of seventy more bodies that currently lack formal recognition are thought likely to meet the definition, and can expect formal recognition at some time in the future.