Chapter 1. The Cycles of the Sky

Match each cause on the left with its effect on the right. Earth's rotation axis is tilted Earth spins on its rotational axis. The Sun crosses the celestial equator moving south.

-There is one day each year with the North Pole is most closely pointed toward the Sun. -The Sun rises in the East each day. -The season changes from summer to winter in the Northern Hemisphere.

Identify the parts of the celestial sphere.

A- North celestial pole/the star Polaris B- The celestial equator C- A line dividing what you can see from what you can't (your horizon) D- A circumpolar star's path F- The path of a star that rises and sets

Select all of the following constellations that are considered part of the zodiac.

Aries Sagittarius Virgo

One____________ of a planet is a single trip around the Sun. One _________________ is a day. (Hint: Both terms start with "r".)

Blank 1: revolution Blank 2: rotation

What causes constellations to be visible only at certain times of the year?

Constellations are in the sky every day, but if the Sun is in the same part of the sky, a constellation cannot be seen due to the Sun's glare.

One year on Earth is the time it takes for ____.

Earth to make one revolution (orbit)

Which of the following would take one year to observe?

The cycle of the constellations in the night sky.

If the Moon enters its waxing crescent phase tonight, then what lunar phase will you see in approximately two weeks?

waning gibbous

Order the events by the length of time each takes, with the longest at the top and the shortest at the bottom. Instructions

1. EARTH ORBITS THE SUN ONCE 2. THE SUN MOVES THROUGH ONE CONSTELLATION 3. EATH ROTATES ONCE 4. THE SUN RISES AND LATER SETS

How many hours of daylight are there on Earth's equator at the time of the summer solstice?

12

Eclipses often occur in pairs with a solar eclipse followed approximately _____ later by a lunar eclipse, or vice versa.

14 days

How long does it take for the dates of eclipses to repeat?

18.6 years

What time will the waning gibbous Moon (Day 19) be highest in the sky?

3 A.M.

As the Moon moves eastward from the Sun and its phase changes, it rises about _____ later each night.

49 minutes

The Earth must turn about an additional 90° to bring the Moon to approximately the same position as the Sun. How long does it take Earth to rotate those extra 90°?

6 hours

As viewed from Earth, how do the stars appear to move relative to the north celestial pole?

Counterclockwise around the pole

Select all the reasons why we do not have eclipses every month.

Earth and the Moon have orbits that are tilted compared to each other. The Moon's orbit is tilted 5 degrees from the ecliptic. The Moon may pass above or below Earth's shadow.

Which of the following is responsible for Earth's seasons?

Earth's rotation axis is tilted compared to its orbit.

Select the statements that apply to a total lunar eclipse.

Earth's shadow falls on the Moon. Eclipses only occur when the Moon is within 0.5° of crossing the ecliptic.

Usually the entire night side of Earth can see a lunar eclipse, but solar eclipses are only seen in small areas and happen much faster. This is mostly because ____.

Earth's shadow is much bigger than the Moon's shadow

The beginning of summer and of winter mark the times of year when the Earth pauses in its north-south motion and seems to stand still before reversing direction.

False

True or false: The North Pole and the South Pole both get 24 hours of daylight at the same time.

False

True or false: The stars of a constellation are found close together in space.

False

Why does the Sun rise and set?

It appears to move because of Earth's rotation.

Select all the answers that correctly describe the precession of the Moon's orbit.

It causes the dates of eclipses to shift by about 20 days per year. It is a slow change in the plane of the Moon's orbit.

Considering the Moon is moving counterclockwise, why is the Moon seen as a waning crescent at the location labeled 'A' and not a waxing crescent?

It gets closer to the Sun and therefore the sunlit portion is turning away from us.

Why is the concept of the celestial sphere useful to us?

It is a convenient way to describe the location of celestial bodies. It is a convenient way to visualize the motion of celestial bodies.

Why is the concept of the celestial sphere useful to us?

It is a convenient way to visualize the motion of celestial bodies. It is a convenient way to describe the location of celestial bodies.

In the celestial sphere model, why does a person standing on Earth only see half of the sphere in the night sky?

It is below the horizon.

Select all the statements that describe the celestial equator.

It lies directly above Earth's equator. Stars on the celestial equator rise due east. It lies on the celestial sphere

Which celestial objects rise in the east and set in the west as seen from Earth? (Select all that apply.)

Jupiter stars near the celestial equator the Moon the Sun

Which parts of Earth receive 24 hours of daylight for part of the year? (Select all that apply.)

Latitudes above 66.5° N (the Arctic Circle) Latitudes below 66.5° S (the Antarctic Circle)

Select all the statements about constellations that are true.

Many constellations represent animals. Cultures often linked the appearance of constellations to seasonal events.

Select the statements that apply to solar eclipses.

Partial eclipses occur more often than total eclipses. The Moon's shadow falls on Earth. They can be annular eclipses. They only occur during new moon.

Earth both revolves and rotates. Match the terms to their definitions. REVOLUTION ROTATION AXIS SUN

REVOLUTION- One orbit around the Sun ROTATION- One 360° turn or spin AXIS - What Earth rotates on SUN - What Earth revolves around

Which of the following correctly describe the motions of stars? (Check all that apply.)

Stars appear to move from east to west in the sky, but that is really caused by Earth's spin. All stars move through space, but they are so far away that it is hard to see them move.

How is the heating of a section of Earth's surface changed when that surface is tilted with respect to the Sun, instead of facing the Sun directly?

Sunlight reaching the tilted surface is less concentrated, so the surface is not heated as much.

Which of the following can happen during a total lunar eclipse?

The Moon may appear dark red.

Every month, the Moon passes between Earth and the Sun (new moon) and on the opposite side of Earth from the Sun (full moon). Why don't we see eclipses every month?

The Moon's orbit is tilted.

Select all of the following that are a consequence of Earth's tilt.

The Southern Hemisphere has winter when it is summer in the Northern Hemisphere. The North Pole is warmer in June than in December.

Earth's tilt is responsible for which of the following? (Select all that apply.)

The Sun appears to move north and south on the celestial sphere (changes declination) over a year. The North Pole experiences daylight for six months.

Select all the observations of the sky you might make over the course of a year.

The Sun passes through all the signs of the zodiac. Constellations reappear in the night sky at the same time of year each year. Different stars are blocked out by the Sun.

Select all the statements that apply to the Sun's path on the winter solstice in the Northern Hemisphere.

The Sun rises in the southeast. The Sun's path across the sky is the shortest all year.

Select all of the statements about the seasons that are correct.

The Sun warms the ground more directly in the summer. There are more daylight hours in the summer than in winter.

Select all the choices that correctly describe equinoxes or solstices.

The fall or autumnal equinox occurs near September 22. The term equinoxes is obtained from the Latin word for equal nights. When the sun is on the celestial equator, the days and nights are of equal length.

If a solar eclipse occurs during a new Moon in February, what would be the closest time for a lunar eclipse to occur?

The full moon immediately before or after

Why is the new moon more difficult to see from Earth than the full moon?

The illuminated hemisphere of the moon is facing completely away from us. It rises at the same time as the Sun.

Select all that apply to a total solar eclipse.

The sky may become dark as night. The Moon completely covers the Sun.

Why does the Moon exhibit phases?

The sunlit portion that we see changes as the Moon orbits Earth.

Select all the choices that describe the path of Sun in the sky if you are at a latitude between 23.5° north and 23.5° south.

The twilight period is shorter than at other latitudes. On some days, the Sun can reach a point directly overhead.

The Sun reaches its highest point in the sky on the summer solstice, so why is the hottest time of year roughly six weeks after the solstice?

The water in the oceans takes a long time to warm up.

Stars appear as points on the sky, some brighter than others. Why?

Their brightness depends strongly on both how much light a star produces and how far away it is.

Select all of the following that describe circumpolar stars.

They always remain above, or below, the horizon. They are found close to one of the celestial poles.

True or false: The dates of eclipses repeat every 18.6 years

True

Which of the following are names of phases of the Moon? (Select all that apply.)

Waning gibbous New moon Waxing crescent Full moon

Which one of the following is not a complete name of a lunar phase?

Waxing

Identify the true statements about the celestial sphere model. (Select all that apply.)

We treat all stars as being at the same distance from Earth. The dome seems to stretch to where the sky meets the ground along the horizon. We imagine that the stars lie on the inside of a gigantic dome that stretches overhead.

What is a constellation? (Select all that apply.)

a group of stars that form a fixed pattern in the sky an area of the sky for conveniently locating objects

A(n) is a grouping of stars that represents a story or symbol of consequence to a culture and can be handy for locating objects on the celestial sphere.

constellation

Why would an astronomer living 5000 years ago probably recognize constellations visible in our night sky? The patterns ____.

do not change appreciably over 5000 years

One day on earth is the time it takes for

earth to rotate once

On the vernal and autumnal equinox, the Sun rises due ____.

east

Astronomers call the line that the Sun traces across the celestial sphere the _____

ecliptic

True or false: A star that is bright in the night sky must be closer to Earth than fainter stars.

false

If there is a new Moon today, then what phase will the Moon have in one week?

first quarter

The figure shows the arrangement of Earth, the Sun, and the Moon for a ____.

lunar eclipse

The celestial sphere describes the position of stars in a way which makes the Universe easier to comprehend. This is a good example of a .

model

A total solar eclipse occurs when the __________ passes between Earth and the__________ .

moon sun

What time will the new Moon (Day 1) be highest in the sky?

noon

The Sun rises due east and sets due west ____.

only on an equinox

The tilt of the Moon's orbit shifts a little bit each year, which changes the dates eclipses occur each year. This shift of the orbital plane is called _________.

precession

Scientific models are ____. (Select all that apply.)

representations of nature typically only useful over specific ranges of sizes or conditions used to predict behavior or outcomes

The figure shows the arrangement of Earth, the Sun, and the Moon for a ____.

solar eclipse

The term derived from the Latin word for the Sun being stationary is ______ . This occurs when the sun seems to stand still before reversing its direction.

solstice or solstices

The light we see from phases of the Moon comes from ____.

sunlight reflected by the Moon

Solar eclipses can be hard to observe because ____. (Select all that apply.)

totality lasts only a few minutes, so clouds can be a problem the eclipse path is narrow

The ecliptic is a line on the celestial sphere. It ____. (Select all that apply.)

traces the path of the Sun over a year is the projection of Earth's orbit onto the celestial sphere

Of winter, spring, summer, and fall, if you are in Phoenix, AZ, you would expect that a stick would cast the longest shadow at noon during ____.

winter