Mash Burnedead
Member
That same year in 1951, astronomer Kuiper was the first to hypothesise that there is a belt of icy objects beyond Neptune or what he described as dark comets or Pluto around the Sun. They can be forced by gravity into paths that allow them to approach the sun and become short-period comets with well defined orbital cycles, usually not exceeding 200 years. That, on the other hand, can take 30 million years to orbit; long-period comets, which originate from the Oort Cloud which lies 100,000 times farther from the Earth-Sun distance. Each has a nucleus of frozen gas and dust; the nucleus creates a coma as the comet gets closer to the sun. Solar wind and sun radiation exerts this pressure and as a result cause the coma to have two tails – one of dust and the other of ionized plasma. The majority of comets travel safely within our solar system but a few called sun grazing comets fly too close to the Sun to become disrupted or burned up.
