Eukaryotic Cells: Structure, Nucleus, and Types
- This text provides information about comets, covering their characteristics, structure, models, and types.
- * Core (Nucleus): A mixture of ice (water, carbon dioxide, ammonia, methane) and dust.
- * Sandbank model * Pure ice nucleus * Ice conglomerate model * Porous core model * Snowball model * Crust formation model
Comet Facts - Summary
This text provides information about comets, covering their characteristics, structure, models, and types. Here’s a breakdown:
1. Comet Features:
* composition: Frozen ice and cosmic dust.
* Orbit: Oval path around the sun.
* Behavior: Easily changed by the sun’s heat.
2.Comet Physical Structure:
* Core (Nucleus): A mixture of ice (water, carbon dioxide, ammonia, methane) and dust. Typically less than 10km in diameter, with a hard, non-evaporative crust.
* Coma: A temporary atmosphere of gas and dust formed by evaporation of the core.
* Tail: Two types:
* dust Tail: Formed from evaporating ice particles.
* Gas (Plasma) Tail: Formed by ionization and carried by the solar wind. Can be disrupted by decreased ion production or increased solar wind pressure.
3. Comet Core Models (Proposed by Scientists):
* Sandbank model
* Pure ice nucleus
* Ice conglomerate model
* Porous core model
* Snowball model
* Crust formation model
4. Comet Types (Based on Orbital Period):
* Long Period Comets:
* Originate from the Oort Cloud.
* Very long orbits (hundreds to thousands of years).
* Influenced by the gravity of giant planets (Jupiter, Saturn).
* Short Period Comets:
* Originally thought to come from the Oort Cloud, but current research suggests this isn’t sufficient. (The text ends mid-sentence regarding short period comets).
Related Articles (linked within the text):
* NASA discovers interstellar comet traveling at super speed.
* Astronomers find comet 12 times larger than the dinosaur destroyer.
* What happens when a comet approaches the sun? The tail gets longer.