Since, the discovery of Pluto the Trans-Neptunianregion, also called as
Edgeworth-Kuiper belt, of our solar
system was attracting scientists all around the world. Edgeworth-Kuiper belt,
is similar to the asteroid belt although far more larger than the asteroid belt,
it mainly contains the remnants of the solar system. The classical belt is
residence of three dwarf planets –PLUTO, HAUMEA and MAKEMAKE.
Kuiper belt extends from the orbit of Neptune (at 30 AU) to
approximately 50 AU from the Sun. “Triton” Neptune’s moon is also known to be
originated from the Kuiper belt region; lots of studies over the topic have
shown that the belt is dynamically stable. Pluto is the largest known member of
the Kuiper belt, if the scattered disc is excluded .Often Kuiper belt is
confused with the Oort-Cloud but reality is that Oort cloud is thousand times
more distant than the belt is.Fredrick.c.leonard was the first person to
suggest regarding the region .But, it was in 1951 Gerard Kuiper achieved a
major breakthrough in the research.Later as the evolution takes place a
hypothesis were proposed.
The famous "dirty
snowball" hypothesis for cometary structure thought that a "comet
belt" might be massive enough to cause the purported discrepancies in the
orbit of Uranus that had sparked the search for Planet X or at the very least,
to affect the orbits of known comets. Observation, however, ruled out this hypothesis.
In 1977, Charles Kowal discovered 2060 Chiron, an icy planetoid with an
orbit between Saturn and Uranus. He used a blink comparator; the same device
that had allowed Clyde Tombaugh to discover Pluto nearly 50 years before. In
1992, another object, 5145 Pholus, was discovered in a similar orbit. Today, an
entire population of comet-like bodies, the centaurs, is known to exist in the
region between Jupiter and Neptune. The centaurs' orbits are unstable and have
dynamical lifetimes of a few million years. From the time of Chiron's
discovery, astronomers speculated that they therefore must be frequently
replenished by some outer reservoir.
Further evidence for the belt's existence later emerged from the study
of comets.It was in 1987 that puzzled by the emptiness of outer space
scientists around the world started finding and vigorous research regarding the
region particularly in US. Through studies a final hypothesis was proposed that
the scattered disc was created when Neptune migrated outward into the
proto-Kuiper belt, which at the time was much closer to the Sun, and left in
its wake a population of dynamically stable objects which could never be
affected by its orbit (the Kuiper belt proper), and a population whose
perihelia are close enough that Neptune can still disturb them as it travels
around the Sun (the scattered disc). Because the scattered disc is dynamically
active and the Kuiper belt relatively dynamically stable, the scattered disc is
now seen as the most likely point of origin for periodic comets.
The size structure and mas of Kuiper Belt was further found out and it
was recorded that at its fullest extent, including its outlying regions, the
Kuiper belt stretches from roughly 30 to 55 AU. However, the main body of the
belt is generally accepted to extend from the 2:3 resonance at 39.5 AU to the
1:2 resonance at roughly 48 AU. The Kuiper belt is quite thick, with the main
concentration extending as much as ten degrees outside the ecliptic plane and a
more diffuse distribution of objects extending several times farther. Overall
it more resembles a torus or doughnut than a belt. Its mean position is
inclined to the ecliptic by 1.86 degrees.
The presence of Neptune has a profound effect on the Kuiper belt's
structure due to orbital resonances. Over a timescale comparable to the age of
the Solar System, Neptune's gravity destabilizes the orbits of any objects
which happen to lie in certain regions, and either sends them into the inner
Solar System or out into the scattered disc or interstellar space. This causes
the Kuiper belt to possess pronounced gaps in its current layout, similar to
the Kirkwood gaps in the asteroid belt.
The number and variety of prior speculations on the nature of the Kuiper
belt have led to continued uncertainty as to who deserves credit for first
proposing it. But, still it continues to be discovered through and remains a
topic of debate.
-RUTURAJ BARGAL
