Pluto - Charon system

Pluto - Charon system

The largest satellite of Pluto is Charon.

Geography

Keywords

Pluto - Charon system, Pluto, Charon, moons of Pluto, Kuiper Belt, Solar System, dwarf planet, Sun, Hydra, Nix, Kerberos, Styx, astronomy, geography

Related items

Scenes

Pluto was regarded the smallest planet of the Solar System, until 2006. Its diameter is smaller than that of the Moon (2,372 km or 1,474 mi). However, it has been recategorized as the largest dwarf planet. It is 39.5 times farther from the Sun than Earth.


Its largest natural satellite is Charon. Relative to Pluto, its size is considerable (diameter: 1,208 km or 751 mi), their size ratio is 2 to 1, thus the Pluto-Charon system was earlier considered a binary planet system.

Their mass ratio is 8 to 1, their common center of mass is outside Pluto, thus they revolve about each other.
Mean density of Pluto is 1.87 g/cm³ (0.0676 lb/in³). It is composed of materials compressed by high temperature. Its surface is mainly composed of frozen nitrogen and methane, which melt during the day and create a thin atmosphere.

Average temperature: -230°C (-382°F)
Orbital period: around 248 Earth years
Rotation period: 6.39 days
It has 5 known moons

Definition:

Dwarf planet: A celestial body orbiting the Sun massive enough to be spherical but has not cleared its neighboring region. The size of dwarf planets is between that of asteroids and regular planets. Trans-Neptunian dwarf planets are called plutoids.

Data:

Diameter: 2,372 km ( 0.19 Earths or 1,474 mi)

Mass: 1.305·10²² kg (0.0021 Earths or 2.877·10²² lb)

Average density: 1.87 g/cm³ (0.0676 lb/in³)

Surface gravity: 0.063 g

Number of moons: 5

Average distance from the Sun:
5,900,000,000 km (3,666,000,000 mi) = 39.5 AU =
5.5 light hours

Orbit length: 36,530,000,000 km (22,700,000,000 mi) =
244,18 AU

Orbital eccentricity: 0.24880766

Orbital period: about 248 years

Charon (moon):

Average distance from Pluto: 19,600 km (12,180 mi)

Diameter: 1,208 km (751 mi)

  • common center of mass - Due to the mass ratio of Pluto and Charon (8:1) and their large distance their common center of mass is outside Pluto, and both celestial bodies revolve about it.

  • average distance from the Sun: 5,900,000,000 km (3,666,000,000 mi)

  • common center of mass - Due to the mass ratio of Pluto and Charon (8:1) and their large distance their common center of mass is outside Pluto, and both celestial bodies revolve about it.
  • average distance from the Sun: 5,900,000,000 km (3,666,000,000 mi)

Narration

Until 2006, Pluto was classified as the smallest planet in the Solar System, the ninth and the farthest planet from the Sun. In that year, however, the International Astronomical Union reformulated the definition of the term ‘planet.’ In the light of the new definition, the icy celestial bodies similar in size to Pluto and found at the edge of the Solar System in the Kuiper Belt have been categorized as dwarf planets.

Discovered in 1930, Pluto was named after the Roman mythological ruler of the underworld. Pluto has a diameter less than one-fifth that of the Earth, and a mass which is approximately 0.2% that of the Earth. Its surface is composed of frozen nitrogen and methane, with a mean surface temperature of almost -230°C (-382°F).

Pluto is nearly 30 times further from the Sun than the Earth at its closest point to the Sun and almost 50 times further away than the Earth at its furthest point. It takes 6.39 Earth days to rotate around its axis, and 248 Earth years to revolve around the Sun. Pluto has not yet completed half of its orbit since its discovery. It was closest to the Sun in 1989, and is now moving away from it.

Pluto has 5 known moons, the largest of them being Charon, with a diameter nearly half that of Pluto and a mass 8 times smaller relative to Pluto. Charon is the ferryman of Hades, according to Greek mythology. For many decades, Charon was thought to be Pluto’s only moon. Since 2005, however, 4 additional moons have been discovered, that is Hydra, Nix, Kerberos and Styx, listed in order of size.

Pluto and Charon were long considered to be a binary planet system, due to their unusual mass ratio and the fact that their common center of mass is outside Pluto.
Charon is tidally locked, which means that it takes just as long to rotate around its axis as it does to revolve around Pluto. Furthermore Pluto and Charon are locked in a synchronous rotation, which means that they always show the same face to each other.

Related items

Planets, sizes

The inner planets of the Solar System are terrestrial planets while the outer planets are gas giants.

The life-cycle of the Solar System

The formation of the Sun and the planets started with the contraction of a dust cloud about 4.5 billion years ago.

The Solar System; planetary orbits

The orbits of the 8 planets in our Solar System are elliptical.

Earth

The Earth is a rocky planet with a solid crust and oxygen in its atmosphere.

Hubble Space Telescope

The Hubble Space Telescope orbits outside the distorting influence of Earth´s atmosphere.

Interesting astronomy facts

This animation presents some interesting facts in the field of astronomy.

Jupiter

Jupiter is the largest planet of the Solar System, it has two and a half times the mass of all the other planets combined.

Kepler´s laws of planetary motion

The three important laws describing planetary motion were formulated by Johannes Kepler.

Mars

Possible traces of water and life are sought on Mars.

Mars Exploration Program

Space probes and Mars rovers examine the structure of Mars and possible traces of life.

Mercury

Mercury is innermost and smallest planet of the Solar System.

Milky Way

The diameter of our galaxy is about 100,000 light years; it contains more than 100 billion stars, one of which is our Sun.

Neptune

Neptune is the outermost planet of the Solar System, the smallest of the giant planets

Saturn

Saturn is the second largest planet in the Solar System, easily recognisable by its rings.

The Dawn mission

Studying Ceres and Vesta will help us learn more about the early history of the Solar System and how rocky planets are formed.

The New Horizons mission

The New Horizons space probe was launched in 2006, with the objective to study Pluto and the Kuiper Belt.

The Sun

The diameter of the Sun is about 109 times that of the Earth. Most of its mass consists of hydrogen.

Uranus

Uranus is the 7th planet from the Sun, a gas giant.

Venus

Venus is the 2nd planet from the Sun, the brightest object on the night sky (after the Moon).

Added to your cart.