Formation of Comets

Study Notes

Formation of Comets

Comets are icy bodies that originate from the outermost edge of our solar system, the Oort Cloud, which is a vast, spherical shell of icy bodies and cosmic debris surrounding the Sun. Comets are made up of volatile materials such as water, ammonia, and methane, which evaporate when they approach the Sun, creating a glowing coma, or atmosphere, and a long, glowing tail. These tails can point away from the Sun due to the solar wind.

Formation Process

Comets are believed to be remnants from the early solar system, formed when the Sun and its planets were still in the process of formation. The formation process of comets is closely related to the formation of asteroids and other small solar system bodies. According to the solar nebula hypothesis, the solar system developed out of a huge cloud of gases and dust floating through space, which gradually collapsed under gravity to form the Sun and the planets. The material that did not form planets was left over, and this material eventually formed the icy bodies that we now call comets.

Oort Cloud and Kuiper Belt

The Oort Cloud and Kuiper Belt are two important regions in the outer solar system that are believed to be the birthplaces of most comets. The Kuiper Belt is a region of icy bodies and cosmic debris located beyond Neptune's orbit, while the Oort Cloud is a much larger, more distant region that extends far beyond the Kuiper Belt. Comets in the Oort Cloud have very long orbital periods, some taking more than 200 years to complete one orbit around the Sun.

Visible Comets

Bright comets, which can be seen with the naked eye, are relatively rare. On average, only one bright comet appears per decade. The most famous comet is Halley's Comet, which was discovered in 1682 and is known for its regular appearances every 76 years. Another well-known comet is Comet Shoemaker-Levy 9, which broke apart and crashed into Jupiter in 1994.

Asteroids vs. Comets

Although asteroids and comets share some similarities in their formation and composition, there are key differences between the two. Asteroids are generally made of rock and metal, while comets are composed of ices and other volatile materials. Asteroids are typically found in the inner solar system, while comets come from the outer solar system.

Exploration of Comets

NASA and other space agencies have sent numerous missions to study comets, including Giotto, which passed close to Halley's Comet in 1986, Deep Space 1, which flew by comet Borrelly in 2001, and Stardust, which obtained high-resolution images and returned comet dust samples from Comet Wild 2. Upcoming missions include the European Space Agency's Rosetta mission, which will go into orbit around comet Churyumov-Gerasimenko in 2014.

In conclusion, comets are icy bodies that originated from the outermost edge of our solar system and are believed to be leftovers from the early solar system formation process. They are formed in the Oort Cloud and Kuiper Belt and are made up of volatile materials that evaporate when they approach the Sun, creating a visible coma and tail. Exploration of comets has provided valuable insights into the early solar system and our origins.

Description

Learn about the origins and characteristics of comets, including their formation process, the Oort Cloud and Kuiper Belt as their birthplaces, visible comets like Halley's Comet, differences between comets and asteroids, and missions exploring comets by space agencies like NASA.