Where do short-period comets come from?
Between the orbits of Uranus and Neptune there is a zone of over 1 billion or more cometary bodies called the Kuiper Belt. This is the inner edge of a much larger region called the Oort Cloud which we think extends over 1 light year from the Sun and contains trillions of cometary nuclei. Over time, some of the bodies in the Kuiper Belt interact with Uranus and get their orbits altered so that they appear on elliptical paths that take them into the inner solar system to become ‘short-period comets’ with periods of 200 years or less. The Hubble Space Telescope imaged dozens of these Kuiper Belt bodies in 1995, the largest of which is called Kowal’s Objects. The above photograph from a ground-based observatory shows the image of one of the confirmed Kuiper Belt Objects discovered in 1992. Each of these are as big as a typical comet nucleus…and all they are waiting for is the right nudge to alter their orbits and send it into the inner solar system to light up our skies as a periodic com
