The Pluto

The Pluto is the most remote and smallest planet in the Solar System, which every 248 years enters the orbit of Neptune for several decades. Thus, at this time it is closer to the Sun than Neptune. The last such period ended in early 1999.

Pluto is the most remote and smallest planet in the Solar System, which every 248 years enters the orbit of Neptune for several decades

The diameter of Pluto is 2300 km. It is less than even the four Galilean satellites of Jupiter, the satellite of Saturn Titan and the satellite of Neptune Triton. Pluto is only twice as large as its moon Charon, whose diameter is 1,250 km, so the Pluto-Charon system is often called a double planet.

The Pluto makes a complete turn around its axis in 9 hours 17 minutes, and its satellite Charon makes a full turn around Pluto exactly for the same time. At the same time, the same hemispheres of Pluto and Charon are always rotated one to the other. For example, in the "Earth-Moon" system, the same hemisphere of the Moon is always drawn to the Earth, but not vice versa. A person on the side of the Moon near the Earth can see the whole Earth when it turns around its axis, but a person on Charon can never see more than one hemisphere of Pluto.

The Pluto and Charon are ice stony bodies. The temperature at the surface of these cosmic bodies is -2330 C. Therefore Pluto almost freezes; water ice, methane ice, nitrogen ice, ammonia ice and even frozen carbon monoxide - all this is on the surface of Pluto. True, on Pluto, the so-called "tropical oases" were discovered, where the temperature is constantly kept at about -2130 C.

The Pluto is so far away that scientists have almost no idea of its "geography." At the farthest point of its elongated elliptical orbit, Pluto is located at a distance of about 7,4 billion kilometers from the Sun, and in the nearest - at a distance of about 4,4 billion kilometers.

No space probe has ever reached the vicinity of Pluto, and although NASA had plans to send a spacecraft to it, an official order for this has not yet been received. Therefore, the images made by the Hubble Space Telescope show dark and light zones, which may correspond to the places of old and fresh ice, respectively.

The Pluto, like Uranus, is inclined to the side, and its axis of rotation is almost perpendicular to the plane of its orbit. It can be assumed that Pluto, like Uranus, probably suffered from a violent collision. Some astronomers believe that Charon is a fragment of Pluto, formed as a result of a strike on this planet. This is analogous to the theories that the Moon was formed from the collision of the Earth with a certain cosmic object.