AS91187 -EARTH AND SPACE SCIENCE INVESTIGATION

To investigate the relationship between the size of a crater formed and factors affecting the impact of a meteorite when it hits the Earth



as91187.pdf

METEOROIDS, METEORS,  METEORITES, ASTEROIDS, COMETS

Meteoroids, meteors, meteorites, comets, and asteroids are all related to “shooting stars.” But, what to call an object depends on its location and composition. Here is a look at the differences between these objects.

Asteroids

Asteroids are minor planets, including some dwarf planets. They are rocky and orbit a star. Examples of asteroids include Ceres (a dwarf planet), Vesta, and Pallas. Technically, not all minor planets are asteroids. Asteroids are rocky bodies ranging in size from one meter to several hundred meters that are found within the orbit of the furthest true planet of a solar system. Some asteroids are dead comets, which have lost the volatile components that give comets their tails.

Comets

Like asteroids, comets orbit a star. They may contain rocks or dust, but always have a lot of ice. When comets near their star, the volatile ice warms and releases gases, producing a visible atmosphere and tail. Comets usually have highly eccentric elliptical orbits that extend beyond the planets into the Kuiper belt.

Meteoroids

Meteoroids are rocky fragments of asteroids, comets, moons, and planetary collisions. They are much smaller than asteroids, ranging in size from tiny grains up to a meter. Smaller particles are called space dust or micrometeoroids. Like other objects, meteoroids are affected by gravity, but the event that formed them often sends them off on an usual trajectory. In our solar system, most meteoroids come from the asteroid belt, but a few come from comets and fragments of the Moon and Mars formed by impacts.

Meteors

A meteor is a flash of light (shooting star or falling star) seen when a meteoroid, asteroid, or comet heats up in the Earth’s atmosphere. Most meteors come from meteoroids. Millions of meteors occur every day, but most come from meteoroids about the size of a grain of sand.

Meteorites

Meteorites are meteoroids, asteroids, and comets that enter the atmosphere and survive to impact the surface. Relatively recently, scientists had to amend the definition of a meteorite to only include natural solid objects falling to the Earth from space. The earlier definition included any fallen object, such as fallen satellites or rocket boosters.