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.
- ESO telescope reveals what could be the smallest...on October 28, 2019 at 8:43 pm
Astronomers using ESO's SPHERE instrument at the Very Large Telescope (VLT) have revealed that the asteroid Hygiea could be classified as a dwarf planet. The object is the fourth largest in the asteroid belt after Ceres, Vesta and Pallas. For the first time, astronomers have observed Hygiea in sufficiently high resolution to study its surface and determine its shape and size. They found that Hygiea is spherical, potentially taking the crown from Ceres as the smallest dwarf planet in the solar […]
- Team studies binaries to make heads or tails of...on June 25, 2019 at 5:35 pm
A team studied the orientation of distant solar system bodies to bolster the 'streaming instability' theory of planet formation.
- Crater counts on Pluto, Charon show small Kuiper...on February 28, 2019 at 7:12 pm
Using New Horizons data from the Pluto-Charon flyby in 2015, scientists have indirectly discovered a distinct and surprising lack of very small objects in the Kuiper Belt. The evidence for the paucity of small Kuiper Belt objects (KBOs) comes from New Horizons imaging that revealed a dearth of small craters on Pluto's largest satellite, Charon, indicating that impactors from 300 feet to 1 mile (91 meters to 1.6 km) in diameter must also be rare.
- New arguments in favor of a ninth planet in our...on February 27, 2019 at 5:48 pm
Researchers are offering new details about the suspected nature and location of a ninth planet in the solar system.
- Missing-link in planet evolution foundon January 28, 2019 at 4:17 pm
For the first time ever, astronomers have detected a 1.3 km radius body at the edge of the Solar System. Kilometer sized bodies like the one discovered have been predicted to exist for more than 70 years. These objects acted as an important step in the planet formation process between small initial amalgamations of dust and ice and the planets we see today.
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- NASA's Webb to examine objects in the graveyard...on October 29, 2020 at 2:04 pm
Beyond the orbit of Neptune, a diverse collection of thousands of dwarf planets and other relatively small objects dwells in a region called the Kuiper Belt. These often-pristine leftovers from our solar system's days of planet formation are called Kuiper Belt objects, or trans-Neptunian objects. NASA's upcoming James Webb Space Telescope will examine an assortment of these icy bodies in a series of programs called Guaranteed Time Observations shortly after its launch in 2021. The goal is to […]
- Rock types on Ryugu provide clues to the...on September 21, 2020 at 4:00 pm
The asteroid Ryugu may look like a solid piece of rock, but it's more accurate to liken it to an orbiting pile of rubble. Given the relative fragility of this collection of loosely bound boulders, researchers believe that Ryugu and similar asteroids probably don't last very long due to disruptions and collisions from other asteroids. Ryugu is estimated to have adopted its current form around 10 million to 20 million years ago, which sounds like a lot compared to a human lifespan, but makes it a […]
- Evidence supports 'hot start' scenario and early...on June 22, 2020 at 4:00 pm
The accretion of new material during Pluto's formation may have generated enough heat to create a liquid ocean that has persisted beneath an icy crust to the present day, despite the dwarf planet's orbit far from the sun in the cold outer reaches of the solar system.
- Neptune's moon Triton fosters rare icy unionon May 22, 2019 at 7:00 pm
Astronomers using the Gemini Observatory explore Neptune's largest moon Triton and observe, for the first time beyond the lab, an extraordinary union between carbon monoxide and nitrogen ices. The discovery offers insights into how this volatile mixture can transport material across the moon's surface via geysers, trigger seasonal atmospheric changes, and provide a context for conditions on other distant, icy worlds.
- Public invited to help name the largest unnamed...on April 11, 2019 at 2:58 pm
More than 10 years since its discovery, (225088) 2007 OR10 is the largest minor planet in our solar system without a name, and the 3 astronomers who discovered it want the public's help to change that. In an article published by The Planetary Society today, Meg Schwamb, Mike Brown, and David Rabinowitz, the astronomers who helped discover 2007 OR10, announced a campaign inviting the public to pick the best name to submit to the International Astronomical Union (IAU) for official recognition.