Comets

Why can comets approach the Sun from any direction, but asteroids generally orbit close to the plane of the ecliptic?

...oort cloud??

two ways in which a comet's orbit may change:

1) gravitational slingshot by a larger object, usually Jupiter.

what are some of the possible fates of comets?

1)capture: a comet can be caught in an orbit of a larger body. 2)ejection: a comet can come close to a large body and gain enough kinetic energy to be ejected from the solar system. 3)collision: a comet can hit a larger body and become a part of the larger body. 4)preservation: those that survived the previous four fates are preserved and are still possible colliders with the earth.

typical ingredients of a comet nucleus:

A comet's nucleus is like a dirty snowball made of ice. (water ice, carbon dioxide ice, ammonia ice, carbon monoxide, carbonaceous particles, silicate sand)

Describe the various parts of a comet while it is near the Sun.

As the comet gets closer to the Sun, some of the ice starts to melt and boil off, along with particles of dust. These particles and gases make a cloud around the NUCLEUS, called a COMA. The coma is lit by the Sun. The sunlight also pushes this material into the beautiful brightly lit TAIL of the comet.

Why do meteorites contain information about the early solar system, yet the Earth does not?

Meteors have not evolved as much as earth, they are essentially preserved. Some meteorites show clear evidence of strong heating at some time in their past, most likely indicating that they originated on a larger body that either experienced some geological activity or was partially melted during the collision that liberated the fragments that eventually became the meteorites. Others show no such evidence and probably date from the formation of the solar system.

In what ways is the Kuiper belt similar to the asteroid belt, and in what ways do they differ?

both the asteroid belt and kuiper belt consist of mainly small bodies. kuiper belt is much larger (20 times as wide and 20 to 200 times as massive). AB objects are mostly rock and metal. KB objects are mostly ice.

kuiper belt:

huge group of planetoids on the edge of our solar system.

Explain the difference between a meteor, a meteoroid, and a meteorite.

meteor: flash of light that we see in the night sky caused by the friction of a meteoroid passing through our atmosphere. meteoroid: smaller than a kilometer and frequently millimeters in size (usually vaporize in earths atmosphere) meteorite: meteor that survives earths atmosphere and lands on earth

What do meteorites reveal about the age of the solar system?

radioactive dating shows most of them to be between 4.4 and 4.6 billion years old—roughly the age of the oldest lunar rocks

where are most comets found?

usually discovered as faint, fuzzy patches of light on the sky while still several astronomical units away from the Sun. many go by undiscovered.

What causes a meteor shower?

when a comet passes near the sun, fragments dislodge and become part of a meteor swarm which moves at nearly the same orbit as the parent comet. If Earth's orbit happens to intersect the orbit of a cluster of meteoroids, a meteor shower can result.

What are comets like when they are far from the Sun? What happens when they enter the inner solar system?

when comets are not near the sun, they are a small frozen nucleus of ice. it appears as a minute point of light. when it comes to close to the sun, the icy surface becomes too warm to remain stable. Part of it becomes gaseous and expands, forming a diffuse coma ("halo") of dust and evaporated gas around the nucleus.