Page 17 - Life beyond the Karman

Kuiper Belt
The Kuiper Belt is one of the largest structures in our solar system and one of the icy bodies extending far beyond the orbit of Neptune. It is home to Pluto and Arrokoth. Both worlds were visited by NASA’s New Horizons spacecraft. There may be millions of other icy worlds in the Kuiper Belt that were left over from the formation of our solar system. Scientists call these worlds Kuiper Belt objects, or trans-Neptunian objects. Trans- Neptunian objects are objects in our solar system that have an orbit beyond Neptune. Pluto, Eris, Haumea and Quaoar are all Kuiper Belt objects.
The Kuiper Belt should not be confused with the Oort Cloud, which is a much more distant region of icy, comet-like bodies that surrounds the solar system, including the Kuiper Belt. Both the Oort Cloud and the Kuiper Belt are thought to be sources of comets.
The inner, main region of the Kuiper belt ends at around 50 astronomical units from the sun. Overlapping the outer edge of the main part of the Kuiper Belt is a second region called the scattered disk, which continues outwards for nearly 1,000 astronomical units, with some bodies on orbits that go even further beyond.
The Kuiper Belt is a source of comets, as it very slowly erodes. Pieces produced by colliding Kuiper Belt Objects can be pushed by Neptune’s gravity into orbits that send them sunward,
where Jupiter’s gravity further corrals them into short loops lasting 20 years or less. These are called short-period Jupiter- family comets. Given their frequent trips into the inner solar system, most tend to exhaust their volatile ices fairly quickly and eventually become dormant or dead comets with little or no detectable activity. Researchers have found that some near-Earth asteroids are actually burned-out comets, and most would have started out in the Kuiper Belt.
Oort Cloud
In 1950, astronomer Jan Oort proposed that certain comets come from a vast, extremely distant spherical shell of icy bodies surrounding the solar system. This giant swarm of objects, now named the Oort Cloud, occupies space at a distance of between 5,000 and 100,000 astronomical units.
The Oort Cloud is a giant spherical shell surrounding our solar system. It is like a big, thick-walled bubble made of icy pieces of space debris. In the silence and darkness between the stars, where our sun appears as just a particularly bright star, a group of icy objects collectively called the Oort Cloud coast along their orbits around a porch light. According to astronomers, the Oort Cloud might contain billions, or even trillions, of objects.
Because the orbits of long-period comets – which take more than 200 years to orbit the sun – are so long, scientists suspect that the Oort Cloud is the source of most of those comets.
“ The Kuiper Belt should not be confused with the Oort Cloud, which is a much more distant region of icy, comet-like bodies that surrounds the solar system, including the Kuiper Belt.
LIFE BEYOND THE KÁRMÁN LINE - OUTER SPACE
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