The Oort Cloud. Giant Comet From the Oort Cloud Will Pass by the Sun in 2031

The Oort Cloud is the most distant region of our solar system. Even the nearest objects in the Oort Cloud are thought to be many times farther from the Sun than the outer reaches of the Kuiper Belt.


Unlike the orbits of the planets and the Kuiper Belt, which lie mostly in the same flat disk around the Sun, the Oort Cloud is believed, to be a giant spherical shell, surrounding the rest of the solar system. It is like a big, thick-walled bubble made of icy pieces of space debris, the sizes of mountains and sometimes larger. The Oort Cloud, might contain billions, or even trillions, of objects.


The distance from the Sun to the Oort Cloud, is so enormous that it’s useful to describe, it not in the more common units, of miles or kilometers, but astronomical units. One astronomical unit (or AU) is the distance between Earth and the Sun. Pluto’s elliptical orbit, carries it as close as 30 AU from the Sun, and as far as 50 AU. The inner edge of the Oort Cloud, however, is thought to be between 2,000 and 5,000 AU from the Sun. The outer edge might be 10,000 or even 100,000 AU, from the Sun, that's one-quarter to halfway between, the Sun and the nearest neighboring star.


The Oort Cloud is a predicted collection, of icy objects farther away than everything else, in the solar system. It fits with observations of comets in the planetary region, of the solar system, but scientists have yet to observe, any object in the Oort Cloud itself.


The Oort Cloud is a spherical layer of icy objects, surrounding our Sun, a star, and likely occupies space, at a distance between about 2,000 and 100,000 astronomical units from the Sun.



Long-period comets (which take more than 200 years to orbit the Sun) probably come from the Oort Cloud, which is sometimes described as a “cometary reservoir."


Predictions show the Oort Cloud, may contain more than a trillion icy objects.



When comets from the Oort Cloud approach the Sun, their surface ices vaporize, producing a cometary atmosphere (a coma) and often two tails (one dust, one gas) that can reach hundreds or even millions of miles (or kilometers) in length. The activity subsides, and the coma collapses, when the comet’s orbit carries it far enough away from the Sun.


No missions have been sent to explore the Oort Cloud yet, but five spacecraft will eventually get there. They are Voyager 1 and 2, New Horizons, and Pioneer 10 and 11. The Oort Cloud is so distant, however, that the power sources for all five spacecraft will be dead centuries before they reach its inner edge.


The frozen, comet-like bodies of the Oort Cloud, are not capable of supporting life as we know it.


The Oort Cloud is named for Jan Oort, the Dutch astronomer, who predicted its existence in the 1950s.



Giant Comet From the Oort Cloud Will Pass by the Sun in 2031

Astronomers used about 40 observations of the object, which is called 2014 UN271, to estimate its size and orbit


One of the largest comets ever documented is going to make its closest pass to the Sun in 2031.


The International Astronomical Union’s Minor Planet Center announced new details about the object, including its name, 2014 UN271, on June 19, George Dvorsky reports for Gizmodo. 2014 UN271 is between 62 and 230 miles wide—unusually large for a comet—and it is currently careening through the solar system, traversing about the distance between the Earth and the Sun each year. And at its closest point, 2014 UN271 will be about ten times farther from the Sun than Earth,


2014 UN271 may develop the recognizable coma and tail of a comet as it gets closer. Observations of the object could help astronomers better understand a mysterious region called the Oort Cloud that surrounds our solar system. The object’s visit to the inner solar system may also be the birth of a long-period comet. But astronomers will have to wait and see what happens.



2014 UN271 was identified based on data collected between 2014 and 2018. Based on the object’s eccentric orbit, astronomers suspect that it originated in the Oort Cloud, a mysterious region of ice and rocks that surrounds the solar system.


The Oort Cloud exists just beyond the reaches of the heliosphere, a bubble of plasma created by the Sun, It sits about 2,000 to 5,000 times farther in space than the distance between Earth and the Sun.


That means that Voyager 1, a space probe that was launched 40 years ago, is now only one-tenth the distance between the edge of the Solar System and the Oort Cloud. It would take the probe another 300 years to reach the cloud, and by then, its power source will probably be dead.


That’s why comets with unusually long orbits like 2014 UN271 and last year’s NEOWISE offer a better opportunity to understand the makeup of the Oort Cloud. Average comets usual complete their orbits in less than 200 years, but long-period comets can take thousands of years. NEOWISE won’t be back for another 6,800 years; 2014 UN271 could take between 400,000 and one million years to return.


“It’s cool that we’re finding it now,”At its current pace, 2014 UN271 will travel from its current point just past Neptune’s orbit to nearly reach Saturn’s orbit in 2031. The object probably will only be about as bright as Pluto’s moon Charon at that point, per New Atlas, so people will likely need to rely on telescopes to capture photographs of it. Then it will head back into distant space.


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