STANDARD 4a

• Students know galaxies are clusters of billions of stars and may have different shapes

GALAXIESSpiral Galaxy• Spiral arms

contain gas, dust, and many bright, young stars

• Older stars are found in the bulge in the center of the galaxy

GALAXIES• The Milky Way, our home galaxy, is a

spiral galaxy

GALAXIES• Barred Spiral Galaxy

GALAXIESElliptical Galaxy• Round shaped• No spiral arms• Relatively little

gas and dust• Contains

mostly older stars

GALAXIESIrregular Galaxy• No regular

shape• Contains a great

amount of gas, dust and young stars

GALAXIES146. The Milky Way is an example of

A an elliptical galaxy

B an irregular galaxy

C a spiral galaxy

D a quasar

ANSWER: C

GALAXIES

147. A typical galaxy may have ________ of stars

A hundreds

B thousands

C millions

D billions

ANSWER: D

GALAXIES148. The galaxy pictured below would

best be classified as a(n)

A barred galaxy

B spiral galaxy

C irregular galaxy

D elliptical galaxy

ANSWER: B

STANDARD 4b

• Students know that the Sun is one of many stars in the milky Way galaxy and that stars may differ in size, temperature, and color

STARS

• Stars are the source of all light in the universe

• Stars produce energy through nuclear fusion, the combining of hydrogen atoms to form helium

• The sun is an average size star

STARS

STARS

• Stars differ in many ways, including temperature, color, size, composition, and brightness

• The color and temperature are related– Blue stars are hot and bright – Yellow stars are of average temperature

and brightness– Red stars are the coolest and the least

bright

STARS

• Other types of stars include:– a. Blue giants – Massive blue stars that are

very bright and hot– b. Red giants – Massive red stars that are

very bright but cool– c. White dwarfs – very small stars that are

hot but very dim

STARS

• Every star begins its life as part of a nebula, a cloud of dust and gas

• Gravity pulls the dust and gas together to form a star at the center

• When the star becomes dense enough, nuclear fusion begins and the star lights up

STARS

• Eventually the star’s fuel runs out, then– Medium stars expand to become red

giants, then shrink to become white dwarfs

– Massive stars explode in a super nova and then end up as either a neutron star or a black hole

STARS

STARS• Hertzsprung-Russell diagram is used to

classify stars by surface temperature and brightness.

• 90% of stars spend of their lives as main-sequence stars and form the center diagonal on the H-R diagram

STARS

149. What color star has the highest surface temperature?

A blue

B red

C white

D yellow

ANSWER: A

STARS150. Why do stars and other large celestial

objects have a spherical shape?

A All objects become spherical when they melt

B Atomic and molecular forces cause all objects to become spherical

C Gravity attracts matter within these objects toward a central point

D Multiple collisions cause these objects to become rounded

ANSWER: C

STARS

151. Every star begins its life as a

A nebula

B white dwarf

C black hole

D pulsar

ANSWER: A

STARS152. What determines whether a star

becomes a white dwarf or a supernova?

A its color

B its diameter

C its mass

D its temperature

ANSWER: C

STARS

153. According to the diagram, which of the following stars is the coolest and dimmest

A Zeta Eridani

B Procyon

C the sun

D Barnard’s Star

ANSWER: D

STARS

154. Which of these stars is a main sequence star?

A the sun

B Sirius B

C North Star

D Aldebaran

ANSWER: A

STANDARD 4c

• Students know how to use astronomical units and light years as measure of distance between the Sun, stars, and Earth

MEASUREMENT IN SPACE• Measure

distances in the solar system by using the astronomical unit (AU).

• It is the average distance between the Earth and the sun (93 million miles)

MEASUREMENT IN SPACE

• The distances between stars is so vast that we measure these distances in light-years.

• Light-year is the distance light travels in one year (9.5 x 1015 m), which is 9 trillion km or 6 trillion miles

MEASUREMENT IN SPACE156. If an astronomer observes that an

object in the solar system is twice as far from the sun as Earth is, how far would that object be from the sun in astronomical units?A 1 AUB 2 AUC 3 AUD 4 AU

ANSWER: B

MEASUREMENT IN SPACE

157. What is the approximate distance to Saturn?

A 1 AU

B 1 light-year

C 10 AU

D 100 million meters

ANSWER: C

MEASUREMENT IN SPACE159. The Milky Way is about 100,000

light-years wide. To cross the Milky Way, light takes aboutA 100 yearsB 1,000 yearsC 100,000 yearsD 1,000,000 years

ANSWER: C

STANDARD 4d

• Students know that stars are the source of light for all bright objects in outer space and that the Moon and planets shine by reflected sunlight, not by their own light

STARLIGHTStars: the source of all light in the UNIVERSE

The moon and planets shine at night from reflected light, not from their own light. This light comes only

from the sun or other stars.

STARLIGHT• Stars differ in brightness. A star’s

brightness depends on size and temperature

• Large stars are brighter than small stars and hot stars are brighter than cool stars

• Absolute brightness is the brightness the star would have if it were at a standard distance from Earth

• Apparent brightness is the star’s brightness as seen from Earth.

STARLIGHT• The moon’s phases are the different

shapes of the moon as seen from Earth• The moon’s phases demonstrate that

the moon reflects the sun’s light to Earth• The phases depend on how much of the

sunlit side of the moon faces Earth• A new moon occurs when the moon

moves between the sun and Earth. The sunlit side of the moon faces away from Earth

• A full moon occurs when the entire sunlit side of the moon faces Earth

STARLIGHT

http://www.classzone.com/books/earth_science/terc/content/visualizations/es2503/es2503page01.cfm

STARLIGHT• An eclipse is when an object in space

comes between the sun and another object

• A solar eclipse occurs when the moon moves directly between Earth and the sun, blocking sunlight from reaching parts of Earth’s surface. New moon

• A lunar eclipse occurs when Earth is directly between the moon and the sun, blocking sunlight from reaching the moon. Full moon

STARLIGHT

STARLIGHT

160. What phase of the moon would someone on Earth see when the moon is at position D?A new moonB first quarterC full moonD third quarter

ANSWER: C

STARLIGHT161. On a clear night, a student notices that a

star in the constellation Orion is much brighter than the star next to it. What observation has the student made?A the first star has a greater apparent brightness than the second starB the first star is producing more light than the second starC the first star has a greater absolute brightness than the second starD the first star is farther along in its life cycle than the second star

ANSWER: A

STARLIGHT

162. What produces light in a star?

A combustion

B fluorescent minerals

C nuclear fusion

D reflection of light from planets

ANSWER: C

STARLIGHT163. For a solar eclipse to occur

A the sun must be directly between Earth and the moonB the moon must be directly between

Earth and the sunC the moon must be directly behind the EarthD Earth must be directly between the sun and the moon

ANSWER: B

STARLIGHT164. Four of Jupiter’s satellites (moons) can be

seen from Earth using a telescope. What makes these satellites visible?A Light emitted by the satellitesB light emitted by Earth and reflected by the satellitesC light emitted by Jupiter and reflected by the satellitesD light emitted by the sun and reflected by the satellites

ANSWER: D

STANDARD 4e

• Students know the appearance, general composition, relative position and size, and motion of objects in the solar system, including planets, planetary satellites, comets, and asteroids

SOLAR SYSTEM

• The solar system includes the sun, the nine planets, and all of the other objects orbiting the sun.

• Other objects in the solar system include satellites (moons), asteroids, meteors and comets

SOLAR SYSTEM• The solar system formed from a cloud

of gas and dust, called a nebula, that collapsed due to gravity.

SOLAR SYSTEM

• The inner planets (Mercury to Mars) are small, dense, and rocky. Also called terrestial planets

• The outer planets (Jupiter to Neptune) are large, made mostly of gas, and do not have solid surfaces. Also called the gas giants.

• Pluto is similar to the composition of the inner planets and is now considered a dwarf planet

SOLAR SYSTEM

SOLAR SYSTEMRelative Size of planets in our Solar System

AstronomyOBJECTS IN OUR SOLAR SYSTEM

My Very Energetic Mother Just Served Us Nine Pizzas

Asteroid Belt

SUN

SOLAR SYSTEM

• Comets are small bodies of ice, rock and dust loosely packed together and revolve around the sun in large orbits.

• Originate either in the Kuiper belt or the Oort Cloud. These are regions that extend outside the orbit of Neptune

SOLAR SYSTEM• Asteroids are small,

rocky bodies in orbit around the sun and are located between the orbits of Mars and Jupiter.

• Astronomers believe that asteroids are leftover pieces of the early solar system that never came together to form a planet

SOLAR SYSTEM• Meteoroid is a small,

rocky body that travels through space, usually created when comets or asteroids break up into smaller chunks

• Meteor is a bright streak of light that results when a meteoroid burns up in Earth’s atmosphere

• Meteorite is a meteoroid that reaches Earth’s surface without burning up completely

SOLAR SYSTEM165. You can see the planets at night

because

A they produce their own light

B sunlight reflects from their surfaces

C nuclear fusion takes place in their cores

D their surfaces are brighter than those of the stars

ANSWER: B

SOLAR SYSTEM

166. Which is the largest planet in the solar system?

A Venus

B Jupiter

C Saturn

D Neptune

ANSWER: B

SOLAR SYSTEM

167. What are the four planets closest to the sun called together?

A outer planets

B terrestrial planets

C solar system

D gas giants

ANSWER: B

SOLAR SYSTEM

168. Which planet has polar ice caps containing frozen water and carbon dioxide?

A Venus

B Jupiter

C Mars

D Neptune

ANSWER: C

SOLAR SYSTEM

169. Which is not a characteristic of all of the gas giants?

A surrounded by rings

B many moons

C composed mainly of hydrogen and helium

D rocky surfaces

ANSWER: D

SOLAR SYSTEM171. Which object comes close to the Sun

but is also found far from the Sun in a highly elliptical orbit?

A planet

B asteroid

C comet

D meteoroid

ANSWER: C

SOLAR SYSTEM172. One complete revolution of Earth

around the sun takes about

A one rotation

B one season

C one year

D one eclipse

ANSWER: C

SOLAR SYSTEM173. The asteroid belt is located

A between Earth and Mars

B between Mars and Jupiter

C between Jupiter and Saturn

D between Saturn and Uranus

ANSWER: B