Asteroids

An asteroid is a small, rocky object that orbits the Sun. Most asteroids are found in the asteroid belt, a region of space between the orbits of Mars and Jupiter. They are also called minor planets or planetoids.

Characteristics of Asteroids

• Composition: Asteroids are made up of rock and metal, similar to the composition of the Earth's crust.
• Size: They vary in size, with some as small as pebbles and others as large as hundreds of kilometers in diameter.
• Orbital Path: Asteroids orbit the Sun in elliptical paths, and their orbits can be very eccentric.
• Shape: They come in various shapes, from irregular to nearly spherical.

Formation and Evolution

Asteroids are believed to be remnants from the early formation of the solar system about 4.6 billion years ago. They are thought to be leftover material that didn't form into planets. Their composition can provide clues about the early solar system and the processes that led to the formation of planets.

Impact on Earth

Occasionally, asteroids can collide with Earth. When they enter the Earth's atmosphere, friction causes them to heat up and create a bright streak of light called a meteor. If a meteor doesn't completely burn up and reaches the Earth's surface, it is called a meteorite.

Study Guide

1. What are asteroids made of?
2. Where are most asteroids found?
3. What is the orbital path of asteroids like?
4. How do asteroids vary in size?
5. What happens when an asteroid collides with Earth?
6. What is a meteorite?

After studying this guide, you should have a good understanding of the characteristics, formation, and impact of asteroids.