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  • Elizabeth Cocking

Did you know? the Kuiper Belt


This month . . . The Kuiper Belt. Home to short period comets and icy bodies in the far reaches of our solar system.

The Kuiper Belt is one of the largest structures in our solar system. Its overall shape is like a doughnut extending from the orbit of Neptune to approximately 7.5 billion kilometres from the Sun.

Pluto is the most well-known Kuiper Belt Object (KBO) and the first KBO to be discovered in 1930 at a time before astronomers had reason to expect a large population of icy worlds beyond Neptune. It would be another 62 years before the second KBO was found in 1992. The illustration below shows the positions of spacecraft and planets and the Kuiper Belt in 2017, courtesy NASA.

The Kuiper Belt is named for astronomer Gerard Kuiper who speculated about objects beyond Pluto. His work didn't actually predict the populations of objects in the region, but his ideas were well-known among astronomers such that the general idea of the belt came to be attributed to him.

The first spacecraft to enter the Kuiper Belt was NASA's Pioneer 10 in 1983 however it didn't visit any of the icy worlds. The first spacecraft to actually visit an object in the Kuiper Belt was NASA's New Horizons, which flew by Pluto and its moons in July 2015.

Do not confuse the Kuiper Belt with the Oort Cloud, which is an even more distant, spherical 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.


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