Dust Tail

Definition

The dust tail of a comet is a long, luminous stream of fine dust particles that are ejected from the comet's nucleus and swept back by the pressure of sunlight. It is a key feature of the 'long-haired' comets that are visible from Earth.

5 Must Know Facts For Your Next Test

1. The dust tail is composed of small, solid particles of dust and ice that are released from the comet's nucleus as it approaches the Sun.
2. The dust tail is typically broader and more curved than the gas tail, and it reflects sunlight, making it visible from Earth.
3. The size and brightness of the dust tail can vary greatly depending on the comet's activity and the amount of dust it releases.
4. The dust particles in the tail are pushed away from the Sun by the pressure of sunlight, creating the characteristic curved appearance of the dust tail.
5. The dust tail can extend millions of kilometers in length and is often the most prominent feature of a comet visible from Earth.

Review Questions

• Explain the formation and structure of the dust tail in the context of a comet's life cycle.
  • As a comet approaches the Sun, the heat causes the nucleus to release gas and dust, forming the coma around the nucleus. The pressure of sunlight then pushes the dust particles away from the nucleus, creating the characteristic curved dust tail that extends millions of kilometers in length. The size and brightness of the dust tail can vary depending on the comet's activity and the amount of dust it releases, but it is typically broader and more curved than the gas tail, which is swept back by the solar wind.
• Describe the role of the dust tail in distinguishing 'long-haired' comets from other celestial objects.
  • The prominent dust tail is a key feature that distinguishes 'long-haired' comets from other celestial objects, such as asteroids or meteors. The dust tail is formed by the pressure of sunlight acting on the dust particles released from the comet's nucleus, creating a long, curved stream of visible dust that can extend for millions of kilometers. This distinctive appearance is what gives comets their 'long-haired' or 'hairy' appearance, making them easily recognizable in the night sky and a source of fascination for astronomers and the general public alike.
• Analyze the relationship between the comet's nucleus, coma, and dust tail, and explain how these components work together to create the overall appearance of a comet.
  • The comet's nucleus, coma, and dust tail are all interconnected and essential components that contribute to the overall appearance of a comet. The nucleus, which is the solid, icy core of the comet, releases gas and dust as it approaches the Sun, forming the coma or cloud surrounding the nucleus. The pressure of sunlight then acts on the dust particles in the coma, pushing them away from the nucleus and creating the characteristic curved dust tail. The size and brightness of the dust tail can vary depending on the comet's activity and the amount of dust released, but it is this dust tail that is the most prominent and recognizable feature of a 'long-haired' comet. The interplay between the nucleus, coma, and dust tail is what gives comets their distinctive and captivating appearance in the night sky.

Related terms

Comet Nucleus: The solid, icy core of a comet that contains dust, ice, and other frozen compounds. As the comet approaches the Sun, the nucleus releases gas and dust, forming the coma and tails.

Coma:

The cloud of gas and dust surrounding the comet's nucleus, which is formed as the nucleus heats up and releases these materials when the comet approaches the Sun.

Gas Tail: The second type of comet tail, which is composed of ionized gases that are swept back by the solar wind, creating a long, straight tail pointing away from the Sun.