Name______

Date______Period______

Objective 5.2 Study Guide

  1. What is a star?

A hot, bright ball of gas.

  1. What color stars are the hottest?

Blue

  1. What color stars are the coolest?

Red

  1. When stars are different colors, we can conclude that they have different _____.

a. Sizesc. temperatures

b. Liquidsd. gases

  1. What is a star made of?

a.Gasesc. solids

b.Liquidsd. gases and solids

  1. When white light passes through a prism, it creates a band of color called a (n) _____.

a.Wavelengthc emission line

b.Spectrumd. spectrograph

  1. What can scientists tell about a star from its spectrum?

a.Its compositionc. its composition

and temperature

b.Its aged. its age and

temperature

  1. Stars are now classified by how _____.

a.Hot they arec. far away they are

b.Cold they ared. close they are

  1. The hottest stars are _____?

a. yellowc. red

b. oranged. blue

  1. A star’s magnitude refers to its _____.

a.Temperaturec. size

b.Brightnessd. age

  1. How bright a star appears as seen from Earth

is called apparent magnitude.

  1. Why is the Sun the brightest object in the

sky?

The sun is the brightest object in the sky because it is so close to the Earth.

  1. What unit of measurement do astronomers

use to determine distances from Earth to the

stars?

Light-year

  1. Explain why you see different constellations

in the sky at different times of the year.

As the Earth revolves around the sun, the night side of the Earth points to different parts of the universe.

  1. Most galaxies are classified by their _____.

a.Shapec. age

b.Sized. color

Each of the following statements is true of a spiral galaxy, an elliptical galaxy or an irregular galaxy. Write S for a spiral galaxy, E for an elliptical galaxy, and I for an irregular galaxy.

__E__16. These galaxies contain mostly old stars.

__S__17. The Milky Way is probably this type of

galaxy.

__I__18. Many of these galaxies may have their

shape distorted by neighboring galaxies.

__S__19. Most galaxies are of this type.

__E__20. These galaxies are massive blobs of stars.

__I__21. These galaxies are close companions of

another galaxy.

__S__22. These galaxies have a bulge in the center

and spiral arms.

  1. Large clouds of gas and dust are called

nebulas.

  1. A tight group of stars that looks like a ball is

called a globular cluster.

  1. What is a quasar?

Quasars are the most distant objects in the universe. They give off much more energy than a star.

  1. Why is looking through a telescope like

looking back in time?

It takes time for light to travel through space, so looking through a telescope is like looking back in time. You are seeing what the star or object looked thousands or even millions of years ago.

  1. What does the word planet mean?

Wanderers

  1. The average distance between the sun and

Earth is _____.

  1. The light yearc. the kilometer
  2. The astronomical unitd. the parsec
  1. How many planets are in the inner solar

system?

Four – Mercury, Venus, Earth and Mars.

  1. How many planets are in the outer solar

system?

Five – Jupiter, Saturn, Uranus, Neptune and Pluto.

  1. The inner planets are also called terrestrial

planets.

  1. How do the inner planets differ from the

outer planets?

The inner planets are small, dense and rocky. The outer planets are huge balls of gas.

  1. What separates the inner planets from the

outer planets?

The asteroid belt.

Match the correct definition with the correct term.

__C__34. the time that a planeta. period of

takes to go around rotation

the sun once b. period of

__D__35. the motion of a body revolution

orbiting another body

in spacec. year

__A__36. the amount of time

that an object takes to

rotate onced. revolution

__B__37. the amount of time

an object takes to

revolve around the sun

  1. Which of the terrestrial planets has the

densest atmosphere?

Venus

  1. What causes the high surface temperatures on

Venus?

The dense atmosphere of Venus absorbs the heat from the sun and holds it in the process known as the Greenhouse Effect.

  1. A planet with a prograde rotation appears to

spin counterclockwise as seen from above its

North Pole.

  1. A planet with a retrograde rotation appears

to spin clockwise as seen from above its North Pole.

  1. Explain why Earth appears to be the only

planet suitable to support life.

Earth is located at just the right distance from the sun to keep its water from freezing and cool enough to keep its water from boiling away.

  1. What evidence suggests that there was once liquid water on Mars?

a. the Martian icecapsc. features like

wave patterns

b. features like dry riverbedsd. water vapor

in its

atmosphere

  1. Give two reasons Mars is a cold planet.

It has a thin atmosphere that cannot trap

heat. It is located much farther out from

the sun than Earth is.

  1. The largest extinct shield type volcano on

Mars is called Olympus Mons.

  1. A planet that has a deep, massive atmosphere

is called a gas giant.

  1. What is Jupiter’s Great Red Spot?

a. thick layers of clouds

b. metallic hydrogen

c. a huge storm system

d. colorful organic molecules

  1. What happens to the gases in Jupiter’s

atmosphere as the depth increases?

As depth and pressure increases, hydrogen gas turns into a liquid form. Deeper still, the liquid hydrogen changes into a liquid, metallic state. The deeper the atmosphere gets, the hotter the temperature is.

  1. What are Saturn’s rings made of?

Icy particles

  1. What is unusual about Uranus’s axis of

rotation?

It is tilted almost 90°and lies on its side.

  1. What drives the belts of whirling clouds and

storms visible in images of Neptune’s atmosphere?

The release of thermal energy causes the warm gases to rise and the cool gases to sink. This produces the wind patterns that create the belts of clouds.

  1. What does the sun look like from the surface

of Pluto?

The sun looks like a distant, bright star.

  1. What is unusual about Pluto’s moon?

Charon is more than half the size of Pluto.

  1. All of the planets have moons EXCEPT for

Mercury and Venus.

  1. What happens to impacts on the surface of

bodies without an atmosphere?

Without an atmosphere, they are preserved unchanged.

  1. What is the current theory about the origin of

the moon?

The current theory is that a large, Mars-sized object collided with Earth. Part of the Earth’s mantle was blasted into orbit around the Earth to form the moon.

  1. What materials are comets made of?

Ice, rock and cosmic dust

  1. Why are comets sometimes called “dirty

snowballs?”

They are called “dirty snowballs” because of their composition. They are made of ice with pieces of rock and dust frozen into them.

  1. What is unusual about the orbit of a comet?

It is highly elliptical when compared to the orbit of a planet or moon.

  1. What happens to the two “tails” of a comet?

The dust tail follows the orbit around the sun. The ion tail always points AWAY from the sun.

  1. What are asteroids? Where are they located?

Asteroids are small, rocky bodies that orbit the sun. They are located in the asteroid belt between the orbits of Mars and Jupiter.

  1. What is a meteoroid? Where do they come

from?

A meteoroid is a VERY small, rocky body that orbits the sun. Meteoroids are probably pieces of asteroids.

  1. What causes meteor showers?

A meteor shower commonly occurs when Earth passes through the debris field left behind by a comet.

  1. Why does the Earth generally have fewer

impacts than the moon?

Our atmosphere acts as a shield to protect us. Most objects burn up as they fall through the atmosphere and therefore can’t affect us on Earth.

  1. What are the three reasons why most craters

left on Earth are no longer visible?

Erosion, weathering and tectonic forces tend to hide or erase the features of any impact craters that do form.

  1. How often do large objects that could cause

global catastrophe strike Earth?

On average, every few hundred thousand years.