Solar System Sun
Terrestrial Planet Mercury, Venus, Earth (Moon), Mars
Asteroid Belt Ceres, Vesta
Jovian Planet Jupiter, Saturn, Uranus, Neptune
Kuiper Belt Pluto, Haumea, Makemake
Scattered Disc Eris, Sedna, Planet X
Oort Cloud Etc. Scholz’s Star
Small Body Comet, Centaur, Asteroid
These are organized by a classification scheme developed exclusively for Cosma. More…
Eris (minor-planet designation 136199 Eris) is the most massive and second-largest (by volume) dwarf planet in the known Solar System. Eris was discovered in January 2005 by a Palomar Observatory-based team led by Mike Brown, and its identity was verified later that year. In September 2006 it was named after Eris, the Greek goddess of strife and discord. Eris is the ninth most massive object directly orbiting the Sun, and the 16th most massive overall, because seven moons are more massive than all known dwarf planets. It is also the largest which has not yet been visited by a spacecraft. Eris was measured to be 2,326 ± 12 kilometers (1,445.3 ± 7.5 mi) in diameter. Eris’s mass is about 0.27% of the Earth mass, about 27% more than dwarf planet Pluto, although Pluto is slightly larger by volume.
Eris is a member of a high-eccentricity population known as the scattered disk. It has one known moon, Dysnomia. As of February 2016, its distance from the Sun was 96.3 astronomical units (1.441×1010 km; 8.95×109 mi), roughly three times that of Pluto. With the exception of some long-period comets, Eris and Dysnomia are currently the most distant known natural objects in the Solar System.
Because Eris appeared to be larger than Pluto, NASA initially described it as the Solar System’s tenth planet. This, along with the prospect of other objects of similar size being discovered in the future, motivated the International Astronomical Union (IAU) to define the term planet for the first time. Under the IAU definition approved on August 24, 2006, Eris is a “dwarf planet”, along with objects such as Pluto, Ceres, Haumea and Makemake, thereby reducing the number of known planets in the Solar System to eight, the same as before Pluto’s discovery in 1930. Observations of a stellar occultation by Eris in 2010, showed that its diameter was 2,326 ± 12 kilometers (1,445.3 ± 7.5 mi), very slightly less than Pluto, which was measured by New Horizons as 2,372 ± 4 kilometers (1,473.9 ± 2.5 mi) in July 2015. — Wikipedia
Eris (Xena) News -- ScienceDaily Eris News. Eris, formerly known as Xena, is the largest dwarf planet in our solar system. Eris has a moon known as Dysnomia.
Pluto should be reclassified as a planet, experts...
on September 7, 2018 at 3:04 pm
The reason Pluto lost its planet status is not valid, according to new research. […]
New limit on the definition of a planet proposed
on January 23, 2018 at 3:19 pm
A planet can be no bigger than about 10 times the size of Jupiter, an astrophysicist has calculated. […]
Haumea, the most peculiar of Pluto companions,...
on October 12, 2017 at 1:33 pm
The trans-neptunian belt contains four dwarf planets, among which Haumea stands out for its extremely elongated shape and rapid rotation. A stellar occultation makes it possible to establish the main physical characteristics of this previously little known body -- among which most surprising was the presence of a ring. […]
The super-Earth that came home for dinner
on October 4, 2017 at 6:45 pm
It might be lingering bashfully on the icy outer edges of our solar system, hiding in the dark, but subtly pulling strings behind the scenes: stretching out the orbits of distant bodies, perhaps even tilting the entire solar system to one side. It is a possible "Planet Nine" -- a world perhaps 10 times the mass of Earth and 20 times farther from the sun than Neptune. […]
Planet Nine hypothesis supported by new evidence
on July 12, 2017 at 3:04 pm
Last year, the existence of an unknown planet in our Solar system was announced. However, this hypothesis was subsequently called into question as biases in the observational data were detected. Now astronomers have used a novel technique to analyze the orbits of the so-called extreme trans-Neptunian objects and, once again, they point out that there is something perturbing them: a planet located at a distance between 300 to 400 times the Earth-Sun separation. […]
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Hubble spots moon around third largest dwarf...
on May 18, 2017 at 5:00 pm
The combined power of three space observatories, including NASA's Hubble Space Telescope, has helped astronomers uncover a moon orbiting the third largest dwarf planet, catalogued as 2007 OR10. The pair resides in the frigid outskirts of our solar system called the Kuiper Belt, a realm of icy debris left over from our solar system's formation 4.6 billion years ago. […]
ALMA investigates 'DeeDee,' a distant, dim member...
on April 12, 2017 at 3:49 pm
Using the Atacama Large Millimeter/submillimeter Array (ALMA), astronomers have revealed extraordinary details about a recently discovered far-flung member of our solar system, the planetary body 2014 UZ224, more informally known as DeeDee. […]
A chance for the Pluto-huggers? Scientist leads...
on March 21, 2017 at 4:40 pm
Ejected a decade ago from its place among the planets, the distant, icy world of Pluto still has its admirers. […]
Planet or dwarf planet—all worlds are worth...
on March 20, 2017 at 11:29 am
Pluto's status as a "dwarf planet" is once again stirring debate. This comes as some planetary scientists are trying to have Pluto reclassified as a planet – a wish that's not likely to come true. […]
A geophysical planet definition
on February 22, 2017 at 12:54 pm
In 2006, during their 26th General Assembly, the International Astronomical Union (IAU) adopted a formal definition of the term "planet". This was done in the hopes of dispelling ambiguity over which bodies should be designated as "planets", an issue that had plagued astronomers ever since they discovered objects beyond the orbit of Neptune that were comparable in size to Pluto. […]