Named after the Dutch American astronomer Gerard P. Kuiper, and also know known as the Edgeworth-Kuiper Belt, this region had been hypothesized for decades but it was only in 1992 that direct evidence of its existence was found for the first time. The objects in the belt are composed largely of frozen volatiles or “ices” such as water, ammonia, and methane.
When the planets formed 4.6 billion years ago, they formed from an agglomeration of many planetesimals, or small solid celestial bodies. Beyond Neptune, the density of planetesimals was too low and the objects couldn’t accumulate to form another planet. Thus, the planetesimals remained in the outer solar system and are called Kuiper belt objects (KBOs).
Located approximately 30 to 50 AU (astronomical units) from the Sun, objects in the belt range from very small pieces of ice to dwarf planets like Pluto, Haumea, and Makemake. Even a couple of moons of our solar system (such as Neptune’s moon Triton and Saturn’s moon Phoebe) are thought to have formed in the Kuiper belt.
The Kuiper belt is thought to be the source of most short-period comets, particularly those that orbit the Sun in less than 200 years. When these icy objects enter the inner solar system the effects of solar winds and radiation vaporizes the ice creating a thin atmosphere around them known as a coma, occasionally they will also develop a tail. It is believed that the gravitational pull of the outer planets bring bodies from the Kuiper Belt into the inner solar system.
- 1943: Astronomer Kenneth Edgeworth suggests that a reservoir of comets and larger bodies resides beyond the planets.
- 1950: Astronomer Jan Oort theorizes that a vast population of comets may exist in a huge cloud on the distant edges of our solar system.
- 1951: Astronomer Gerard Kuiper predicts the existence of a belt of icy objects just beyond the orbit of Neptune.
- 1992: Astronomers David Jewitt and Jane Luu discover the first KBO (Kuiper Belt object), 1992QB1.
Kuiper Belt Facts
The first mission to the Kuiper Belt is New Horizons. New Horizons will reach Pluto in 2015.
There may be are hundreds of thousands of icy bodies larger than 100 km (62 miles) and an estimated trillion or more comets within the Kuiper Belt.
The first KBO to be discovered was Pluto (discovered in 1930).
Short-period comets (which take less than 200 years to orbit the Sun) originate in the Kuiper Belt.
Most objects of the Kuiper belt have orbits that are stable for over 100 million to 1 billion years.
Trans-Neptunian objects is a common name given to the objects of the Kuiper belt.