Sunday, 9 October 2016

Eris: The Largest Dwarf Planet



Largest known Dwarf planet in our solar system is Eris. It was also one of the first three objects categorized as a dwarf planet. Eris was first not only believed to be larger in size than but also more massive than Pluto. Eris lies beyond the Kuiper belt and is also known as trans-Neptunian Object (TNO). Eris is native to the region of space beyond the Kuiper belt known as scattered disc. With exception of few comets Eris is the most distant known natural object in our solar system. The discovery of Eris was announced in July of 2005, the same day as Makemake and two days after Haumea was discovered. Eris was also known as twin of Pluto.

Eris is slightly larger in size than Pluto. Eris appeared to be larger than Pluto, so its discoverers and NASA firstly called it as the tenth planet of the solar system. This, along with the prospect of other similar objects wandering and being discovered in the future, motivated the International Astronomical Union (IAU) to define the term planet. The International Astronomical Union (IAU) is responsible for classifying and naming the planets. After defining the term “Planets” Eris was named as a dwarf planet along with Pluto. Before Eris was given its current name it was earlier known as UBU 313 and its nickname was Xena. Eris was titled after the Greek goddess “Eris”, a personification of trouble and conflict. This name suited it well because its discovery created problems for naming planets.

Eris is three times farther than the sun as Pluto is. Eris seems to be rocky body surrounded by a thick mantle of ice. Dwarf planet Eris turns out to reflect almost all of the light that falls on it. Surface of Eris is brighter than the snow on earth. The escape velocity of Eris is calculated to be 1.384 km/s. The diameter of Eris is measured to be about 2,397 km. Eris has the density of 2.52 grams per centimeter cubed which is much higher than Pluto. Its high density than Pluto indicates that it’s made of Predominantly Rocky Materials and less ices of other Plutoids. Its surface is almost completely grey, which indicates the layer of Methane ices covering its surfaces. Eris is believed to have an atmosphere of methane when it orbits closer to the sun. Eris has also been suspected to have water Ice on its surface.

Eris also has one moon named Dysnomia. Its moon was named after the daughter of the Greek goddess of Lawlessness. Eris is 27% more massive than Pluto. Eris can be seen in the night sky with some amateur telescopes. It can also be seen with simple telescopes under favorable conditions. Eris orbits the sun in a completely different way, travelling downwards. Orbital period of Eris is about 557 years. The Perihelion of its orbit is 37.77AU and Aphelion is 97.56AU. Eris is although three times away from the sun as Pluto is but during its orbit, it approaches close enough to sun that some of the ices on its surface may warm sufficient to sublime.

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