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…
Oort cloud, named after the Dutch astronomer Jan Oort, sometimes called the Öpik–Oort cloud, is a theoretical cloud of predominantly icy planetesimals proposed to surround the Sun at distances ranging from 50,000 to 200,000 AU (0.8 to 3.2 ly). It is divided into two regions: a disc-shaped inner Oort cloud (or Hills cloud) and a spherical outer Oort cloud. Both regions lie beyond the heliosphere and in interstellar space. The Kuiper belt and the scattered disc, the other two reservoirs of trans-Neptunian objects, are less than one thousandth as far from the Sun as the Oort cloud.
The outer limit of the Oort cloud defines the cosmographical boundary of the Solar System and the extent of the Sun’s Hill sphere. The outer Oort cloud is only loosely bound to the Solar System, and thus is easily affected by the gravitational pull both of passing stars and of the Milky Way itself. These forces occasionally dislodge comets from their orbits within the cloud and send them toward the inner Solar System.Based on their orbits, most of the short-period comets may come from the scattered disc, but some may still have originated from the Oort cloud.
Astronomers conjecture that the matter composing the Oort cloud formed closer to the Sun and was scattered far into space by the gravitational effects of the giant planets early in the Solar System’s evolution. Although no confirmed direct observations of the Oort cloud have been made, it may be the source of all long-period and Halley-type comets entering the inner Solar System, and many of the centaurs and Jupiter-family comets as well.
The existence of the Oort cloud was first postulated by Estonian astronomer Ernst Öpik in 1932. — Wikipedia
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- All is quiet among newly studied Centaurson September 15, 2021 at 5:21 pm
Often, the squeaky wheel, or at least the shiniest object, seems to get all the attention. In a new study led by PSI Research Scientist Eva Lilly, it is the inactive Centaurs that take center stage and illuminate why other Centaurs may be so flashy. Centaurs are icy objects out between the orbits of Neptune and Jupiter that in some cases display comet-like tails and jets. This somehow happens despite being located where it is too cold for this kind of activity to occur due to normal […]
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When a young solar system gets going it's little more than a young star and a rotating disk of debris. Accepted thinking says that the swirling debris is swept up in planet formation. But a new study says that much of the matter in the disk could face a different fate.
- Interstellar comets like Borisov may not be all...on August 23, 2021 at 10:00 am
In 2019, astronomers spotted something incredible in our backyard: a rogue comet from another star system. Named Borisov, the icy snowball traveled 110,000 miles per hour and marked the first and only interstellar comet ever detected by humans.
- Giant comet found in outer solar system by Dark...on June 28, 2021 at 12:20 pm
A giant comet from the outskirts of our solar system has been discovered in six years of data from the Dark Energy Survey. Comet Bernardinelli-Bernstein is estimated to be about 1000 times more massive than a typical comet, making it arguably the largest comet discovered in modern times. It has an extremely elongated orbit, journeying inward from the distant Oort Cloud over millions of years. It is the most distant comet to be discovered on its incoming path, giving us years to watch it evolve […]
- Space object with orbit stretching into the Oort...on June 22, 2021 at 1:40 pm
Astronomers Pedro Bernardinelli and Gary Bernstein discovered a space object recently that has an orbit around the sun and also stretches into the Oort cloud—they have named it 2014 UN271. The researchers made the discovery while studying archival images collected for the Dark Energy Survey over the years 2014 to 2018. Since its discovery, entities such as the MMPL forum, the Minor Planet Center and JPL Solar System Dynamics have been tracking the object and have found that it will make its […]