astr homework 9

Which is closest to the average distance between asteroids in the asteroid belt?

1 million km

What is the size of the largest asteroid?

1000 km

Listed following are some distinguishing characteristics of comets, meteors, and asteroids. Match these to the appropriate category of objects.

Comets:form a coma when near the sun, visible in the sky as a fuzzy patch of light that arises and sets with the stars, most are located either in Kuiper belt or Oort cloud Meteors:visible in the sky as a bright streak of light for only a few seconds, dust particles entering Earth's atmosphere at high speed Asteroids:compositions similar to that of the terrestrial planets, typically orbit the Sun at approximately 3 AU

How does the largest asteroid, Ceres, compare in size to other solar system worlds?

It is about a quarter the size of the Moon.

What would happen if a 1-kilometer object struck Earth?

It would cause widespread devastation and climate change

The following figures show four positions of a comet during its orbit of the Sun. Also shown is the orbit of the Earth around the Sun. Rank the positions of the comet from left to right based on the expected size of its tail, from shortest to longest. (Not to scale; tails not shown.)

The length of a comet's tail depends primarily on the comet's distance from the Sun. It is longer when the comet is closer to the Sun and shorter (or nonexistent) when the comet is farther from the Sun.

How big an object causes a typical shooting star?

a grain of sand or a small pebble

A rock found on Earth that crashed down from space is called _________.

a meteorite

Listed following are several objects in the solar system. Rank these objects from left to right based on their distance from the Sun, from closest to farthest.

a typical asteroid in the asteroid belt, a typical Kuiper belt, a typical Oort cloud object

Listed following are several objects in the solar system. Rank these objects from left to right based on the distance from the Sun at which they are presumed to have formed, from nearest to farthest.

a typical asteroid in the asteroid belt, a typical oort cloud object, a typical kuiper belt object Although Oort cloud comets are now located far beyond the Kuiper belt, they are thought to have formed in the region of the jovian planets. They were then "kicked out" to their current orbits by gravitational encounters with the jovian planets.

When was Pluto discovered?

about 80 years ago

Where are the Trojan asteroids located?

along Jupiter's orbit, 60° ahead of and behind Jupiter

Pluto's gravity affects the orbit of Uranus, and this fact was used to discover Pluto.

false

A typical shooting star in a meteor shower is caused by a ________ entering Earth's atmosphere.

pea-size particle from a comet

Most meteorites are

rocky and primitive