Comets

Definition

Comets are icy celestial bodies that, when they approach the Sun, develop a glowing coma and a tail due to the sublimation of their volatile components. These fascinating objects are considered remnants from the early solar system, holding essential clues about the conditions and materials present during its formation, which plays a significant role in understanding the delivery of organic molecules to early Earth.

5 Must Know Facts For Your Next Test

1. Comets are often referred to as 'dirty snowballs' because they consist primarily of ice and dust.
2. When comets get close to the Sun, the heat causes them to lose gas and dust, forming their characteristic tails that always point away from the Sun due to solar wind.
3. Some scientists believe that comets may have played a critical role in delivering water and organic compounds to Earth, contributing to the origins of life.
4. There are two main types of comets: short-period comets, which orbit the Sun in less than 200 years, and long-period comets, which take more than 200 years to complete an orbit.
5. The study of comets is crucial for understanding early solar system conditions, as their composition can provide insights into the materials present during planet formation.

Review Questions

• How do comets contribute to our understanding of the early solar system and the delivery of organic molecules to Earth?
  • Comets serve as time capsules from the early solar system, preserving ancient materials that can reveal the conditions during its formation. When comets approach the Sun and release gases and dust, they also release organic molecules into space. Some of these molecules could have been deposited on early Earth through impacts, possibly contributing to the development of life by providing essential building blocks like amino acids.
• Discuss the significance of the Oort Cloud in relation to comet activity and organic molecule delivery.
  • The Oort Cloud is a theoretical region filled with icy bodies that serves as a reservoir for long-period comets. When these comets are perturbed by gravitational influences, they can be sent toward the inner solar system. As they approach the Sun and become active, they release gases and organic compounds that may have implications for understanding how life's building blocks were delivered to early Earth through comet impacts.
• Evaluate how current research on comets may change our perspective on life's origins on Earth and potentially elsewhere in the universe.
  • Current research on comets focuses on their chemical makeup and physical properties, which could redefine our understanding of life's origins. If future studies reveal a rich diversity of organic molecules in cometary materials, it could suggest that life's building blocks are more common throughout the universe than previously thought. This would shift our perspective on whether life arose solely on Earth or if other celestial bodies could harbor similar processes, highlighting the potential for life beyond our planet.

Related terms

Nucleus: The solid core of a comet, made up of ice, dust, and rocky material that can range in size from a few hundred meters to tens of kilometers across.

Oort Cloud: A vast, spherical shell of icy objects surrounding the solar system, believed to be the source of long-period comets that occasionally enter the inner solar system.

Organic Molecules: Molecules containing carbon that are essential for life, which may have been delivered to early Earth through comets and other celestial bodies.