Cubewanos have orbits with semi-major axes in the 40 – 50 AU range and, unlike Pluto, do not cross Neptune ’ s orbit.

* 1979 – Pluto moves inside Neptune's orbit for the first time since either was discovered.

* 1930 – While studying photographs taken in January, Clyde Tombaugh discovers Pluto.

* 1978 – Charon, a satellite of the dwarf planet Pluto, is discovered by American astronomer James W. Christy.

* 1735 – Mathematical calculations suggest that it is on this day that dwarf planet Pluto moved inside the orbit of Neptune for the last time before 1979.

* 2012 – Astronomers announce the discovery of S / 2012 P 1, the fifth moon of Pluto.

* 1918 – Venetia Burney, English girl who named of the dwarf planet Pluto ( d. 2009 )

* 2006 – The New Horizons probe is launched by NASA on the first mission to Pluto.

* 2005 – A second photo from the Hubble Space Telescope confirms that Pluto has two additional moons: Nix and Hydra.

* 2: 3 Pluto – Neptune

The relative sizes and type of orbit are similar to the Pluto – Charon ( moon ) | Charon system.

While the majority of plutinos have low orbital inclinations, a substantial number of them follow orbits similar to that of Pluto, with inclinations in the 10 – 25 ° range and eccentricities around 0. 2 – 0. 25, resulting in perihelia inside ( or close to ) the orbit of Neptune and aphelia close to the main Kuiper belt's outer edge ( where objects have 1: 2 resonance with Neptune ).

Percival Lawrence Lowell ( March 13, 1855 – November 12, 1916 ) was an American businessman, author, mathematician, and astronomer who fueled speculation that there were canals on Mars, founded the Lowell Observatory in Flagstaff, Arizona, and formed the beginning of the effort that led to the discovery of Pluto 14 years after his death.

The alcohol pushes the narrator into fits of intemperance and violence, to the point at which everything angers him – Pluto in particular, who is always by his side, becomes the malevolent witch who haunts him even while avoiding his presence.

Such a situation already exists in the Pluto – Charon system.

* February 11 – Pluto moves along its eccentric orbit further from the Sun than Neptune.

* May – Operation Pluto: The plan to construct oil pipelines under the English Channel between England and France is tested in the River Medway.

* June 5 – Calculations indicate Pluto reaches its most recent aphelion ( furthest point from Sun ) on this day ( the next aphelion will occur in August 2113 ).

* March 19 – Pluto is photographed for the first time but is not then classified as a planet.

* July 11 – Pluto ( not known at this time ) enters a fourteen year period inside the orbit of Neptune, which will not recur until 1979.

* July 20 – Pluto reaches, according to sophisticated mathematical calculations, its second most recent aphelion.

* July 23 – Orbital calculations suggest that on this day, Pluto moves outside Neptune's orbit, remaining there for 233 years.

* April 30 – Orbital calculations suggest that on this day Pluto moved inside Neptune's orbit until July 23, 1503.

* New Horizons – first Pluto flyby ( arrival 2015 )

* Charon ( moon ), a moon of the dwarf planet Pluto

The name " cubewano " derives from the first trans-Neptunian object ( TNO ) found after Pluto and Charon,.

Aside from Pluto itself and Charon, the first plutino, 1993 RO, was discovered on September 16, 1993.

*, the prototype cubewano, the first Kuiper belt object discovered after Pluto and Charon.

*, the first binary Kuiper belt object discovered after Pluto and Charon.

For very large objects, with very well known orbital elements ( namely, Pluto and Charon ), diameters can be precisely measured by occultation of stars.

* Pluto and Charon

** Charon, a satellite of Pluto, is discovered.

* 4, 580, 000 km < sup > 2 </ sup > -- Charon ( moon of Pluto )

* 1. 186 Mm — Diameter of Charon, the largest moon of Pluto

* July 14 – NASA's New Horizons spacecraft is expected to fly by Pluto and Charon at 50, 000 kilometers per hour and explore the area for five months, until the distance becomes too great.

Pluto has the relatively large moon Charon and four smaller moons.

Usually, at any given time only the satellite is tidally locked around the larger body, but if the difference in mass between the two bodies and their physical separation is small, each may be tidally locked to the other, as is the case between Pluto and Charon.

The dwarf planet Pluto and its satellite Charon are good examples of this — Charon is only visible from one hemisphere of Pluto and vice versa.

Pluto and Charon are an extreme example of a tidal lock.

This has made Pluto also tidally locked to Charon.

* Charon ( Pluto is itself locked to Charon )