Question

Gerard kuiper belt proposed that certain comets come from a vast, extremely distant, sperical shell of icey bodies surrounding the solar system

Answer 1

Answer:

Explanation:

1930, soon after the discovery of Pluto, astronomer Fred-

erick C. Leonard suggested that Pluto was but one of many

“ultra-Neptunian” or “trans-Neptunian” small bodies. In 1943,

astronomer Kenneth Edgeworth hypothesized that many small,

icy bodies exist in a disc in the region beyond Neptune, having

condensed from widely spaced ancient material, and that from

time to time one of them visits the inner solar system. Eight

years later, Gerard Kuiper proposed the existence of such a

disc, which formed early in the solar system’s evolution. In 1992,

astronomers detected a faint speck of light from an object about

42 AU from the Sun — the first time a Kuiper Belt object (or KBO

for short) had been sighted. (One astronomical unit, or AU, is the

mean distance of Earth from the Sun: about 150 million kilome-

ters or 93 million miles.) More than 1,300 KBOs have been iden-

tified since 1992. They are sometimes called Edgeworth–Kuiper

Belt objects or transneptunian objects — TNOs for short.

The Kuiper Belt should not be confused with the Oort Cloud,

which is a thousand times more distant. 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 between 5,000 and 100,000

astronomical units. No objects residing within the Oort Cloud

have ever been directly observed. The outer extent of the Oort

Cloud is where the Sun’s gravitational influence can be overpow-

ered by that of other stars.

The Oort Cloud probably contains 0.1 to 2 trillion icy bodies in

solar orbit. Occasionally, giant molecular clouds, stars passing

nearby, or tidal interactions with the Milky Way’s disc disturb

the orbit of one of these bodies in the outer region of the Oort

Cloud, causing the object to streak into the inner solar system

as a so-called long-period comet. These comets have very large,

eccentric orbits and are observed in the inner solar system only

once. In contrast, short-period comets take less than 200 years

to orbit the Sun and they travel along the plane in which most of

the planets orbit. They are thought to come from the Kuiper Belt

or from the so-called scattered disc, a dynamic zone created by

the outward motion of Neptune that contains many icy objects

with eccentric orbits. The objects in the Oort Cloud and in the

Kuiper Belt are presumed to be remnants from the formation of

the solar system about 4.6 billion years ago.

The Kuiper Belt extends from about 30 to 55 AU and is prob-

ably populated with hundreds of thousands of icy bodies larger

than 100 kilometers (62 miles) across and an estimated trillion or

more comets. Because KBOs are so distant, their sizes are dif-

ficult to measure. The calculated diameter of a KBO depends on

assumptions about how brightness relates to size. With infrared

observations by the Spitzer Space Telescope, most of the largest

KBOs have known sizes.

One of the most unusual KBOs is Haumea, part of a collisional

family orbiting the Sun, the first found in the Kuiper Belt. The

parent body, Haumea, apparently collided with another object

that was roughly half its size. The impact blasted large icy

chunks away and sent Haumea reeling, causing it to spin end-

over-end every four hours. It spins so .