Astronomy

Final ReviewFinal Review

Geocentric Model

--Earth is in the --Earth is in the center of the center of the system and system and everything everything revolves around revolves around it.it.

Heliocentric Model

--Sun is located at the center of the system.

--The orbit of each planet is an ellipse with the sun at one focus.

Finding the eccentricity of an ellipse

Foci- the two points at the center of the ellipse

Major Axis- the distance across the center of the ellipse

distance between fociEccentricity= length of major axis

Find the eccentricity of this ellipse

=distance between foci length of major axis

= 3.8 cm 7.7 cm

=.494

Rotation

Think SPINNING360°, 24 hoursCoriolis Effect– winds

deflect to the right in the northern hemisphere

Foucault Pendulum—changes the direction of swing of the pendulum

Revolution

The orbiting of the Earth around the Sun360°/365 days = ~1° per dayThe Earth’s axis is always pointed at the

same place

Seasons of the Year

Earth revolves around the Sun

Earth is tilted/inclined on its axis 23.5°

Earth’s axis is always pointed in the same direction

September 21st (Fall)

March 21st (Spring)

June21st

December21st

Phases of the Moon

Caused by the Moon’s revolution around Earth and reflection on Sun

•The moon revolvesat the same speedthat it rotates so weare always lookingat the same face of the moon.

Moon’s Revolution

1 month or 29.5 days

Moon’s Rotation

•Rotation equals its revolution

ECLIPSES

Lunar Eclipse

Solar Eclipse

1. Winter2. Spring3. Summer4. Fall

Earth is farthest from the Sun during the Northern Hemisphere’s summer, and Earth is closest to the Sun during the Northern Hemisphere’s winter. During which season in the Northern Hemisphere is Earth’s orbital velocity greatest?

1. the Moon spins on its axis  2. Earth spins on its axis  3. the Moon travels in an orbit around Earth  4. Earth travels in an orbit around the Sun

Surface ocean currents curve to the right in the Northern Hemisphere because

1. redshift of light from distant galaxies  1. redshift of light from distant galaxies  2. apparent shape of star constellations  2. apparent shape of star constellations  3. presence of volcanoes on Earth  3. presence of volcanoes on Earth  4. presence of craters on Earth’s Moon4. presence of craters on Earth’s Moon

The Big Bang Theory, describing thecreation of the universe, is most directlysupported by the

1.  A  1.  A  2. B  2. B  3. C  3. C  4. D4. D

Which lettered arrow represents the motion that causes the Moon to show phases when viewed from Earth?

Which graph best represents the force of gravity between Earth and the Sun during one revolution of Earth around the Sun?

A. C.

D.B.

The diagram below shows the Moon orbiting Earth, as viewed from space above Earth’s North Pole. The Moon is shown at eight positions in its orbit.

Spring ocean tides occur when the difference in height between high tide and low tide is greatest. At which two positions of the Moon will spring tides occur on Earth?

A. 3 and 7 B. 2 and 6C. 1 and 5 D. 4 and 8

 1. Pluto  2. Mercury  3. Saturn  4. Mars

Which planet has an orbital eccentricity most

like the orbital eccentricity of the Moon?