Astronomy Chapter 2

Choose the correct explanation why the statement makes sense (or is clearly true) or does not make sense (or is clearly false). 1. This statement makes sense, because the constellations visible in the sky depend on latitude. Since Argentina is in the Southern Hemisphere, the constellations visible there include many that are not visible from the United States. 2. This statement doesn's make sense, because the constellations visible in the sky depend on latitude. Since Argentina is in the Northern Hemisphere, the constellations visible there are mostly visible from the United States. 3. This statement makes sense, because the constellations visible in the sky depend on longitude. Since Argentina is to the East from the US, the constellations visible there include many that are not visible from the United States. 4. This statement doesn's make sense, because the constellations visible in the sky depend on longitude. Since Argentina is at the the same longitude, as the US are, the constellations visible there are mostly visible from the United States.

1

How many arcseconds are in a full circle?

1296000 arcseconds

What is the Moon's angular size in arcseconds?

1800 arcseconds

Which of the following statements are true about summer compared to winter? 1. At a given time of day, shadows are longer in summer. 2. Temperatures tend to be warmer in summer. 3. The Sun follows a longer and higher path through your sky in summer. 4. You have more daylight and less darkness in summer.

2,3,4

How many arcminutes are in a full circle?

21600 arcminutes

The Moon's angular size is about 12∘. What is this in arcminutes?

30 arc minutes

How many stars can you see with your naked eye on a clear, moonless night from a dark location?

A few thousand

Which of the following celestial objects do NOT rise in the east and set in the west, as viewed from the Earth? (Assume that all of these objects are visible from your location on Earth, and that none of them are circumpolar.) the Moon galaxies the Sun stars All of these objects rise in the east and set in the west.

All of these objects rise in the east and set in the west

Which of the following celestial objects do NOT rise in the east and set in the west, as viewed from the Earth? (Assume that all of these objects are visible from your location on Earth, and that none of them are circumpolar.) the Sun galaxies the Moon stars All of these objects rise in the east and set in the west.

All of these objects rise in the east and set in the west.

Consider a time when Mars is in the middle of one of its periods of apparent retrograde motion. During this time, Mars appears______ in our night sky and crosses the meridian around_________

Brightest and midnight

Stars that are visible in the local sky on any clear night of the year, at any time of the night, are called _________.

Circumpolar

What is really happening in space during the periods when we see Mars going through apparent retrograde motion?

Earth is passing by Mars in its orbit around the Sun.

What is the basic reason that we have seasons on Earth?

Earth's axis is tilted relative to the ecliptic plane.

At most times, Mars appears to move______ relative to the stars. The exceptions are during its periods of apparent retrograde motion, when Mars appears to move______ relative to the stars.

Eastward and Westward

The seasons on Earth are caused by its elliptical orbit around the Sun. True False

False

t is possible to see the third-quarter Moon near the western horizon at sunrise. True False

False

What happens to Earth's axis as we orbit around the Sun over the course of each year?

It remains pointed in the same direction at all times.

Which of the following statements about the celestial equator is true at all latitudes? 1. It represents an extension of Earth's equator onto the celestial sphere. 2. It extends from your horizon due north, through your zenith, to your horizon due south. 3. It cuts the dome of your sky exactly in half. 4.It extends from your horizon due east, through your zenith, to your horizon due west. 5. It lies along the band of light we call the Milky Way.

It represents an extension of Earth's equator onto the celestial sphere.

What is special about the June solstice?

It's the day on which the Northern Hemisphere receives its most direct sunlight.

The Sun-centered system pictured in the lower window of the video offers a simple explanation for observations of apparent retrograde motion. Should these facts alone have been enough to convince the ancient Greeks that Earth really does go around the Sun?

No, because the Greeks had an Earth-centered model that also accounted for apparent retrograde motion.

At approximately what time would a first quarter Moon rise?

Noon

You are standing on Earth's equator. Which way is Polaris, the North star?

On the Northern Horizon

In spring, the axis points toward

Polaris

If you wanted to document the apparent retrograde motion of Mars, you would need to measure and record Mars's position________ over a period of______

Position among the constellations and Several months

Rank the seasons for the Southern Hemisphere based on Earth's distance from the Sun when each season begins, from closest to farthest.

Summer Fall Spring Winter

If you are located in the Northern Hemisphere, which of the following correctly describes a relationship between the sky and your location? 1. The altitude of the north celestial pole equals your longitude. 2. The altitude of the north celestial pole equals your latitude. 3. The altitude of the celestial equator equals your latitude. 4. The longitude of the north celestial pole is circumpolar, and therefore crosses your zenith at the meridian.

The altitude of the north celestial pole equals your latitude

Which of the following statements does NOT use the term angular size or angular distance correctly? 1. The angular size of the Sun is about the same as that of the Moon. 2. The angular distance between those two bright stars in the sky is about 2 meters. 3. The angular distance between those two houses in the distance is 30 degrees. 4. You can use your outstretched hand against the sky to estimate angular sizes and angular distances

The angular distance between those two bright stars in the sky is about 2 meters.

Which of the following statements does NOT use the term angular size or angular distance correctly? 1. The angular distance between those two houses in the distance is 30 degrees. 2. The angular size of the Sun is about the same as that of the Moon. 3. You can use your outstretched hand against the sky to estimate angular sizes and angular distances. 4. The angular distance between those two bright stars in the sky is about 2 meters.

The angular distance between those two bright stars in the sky is about 2 meters.

What conditions are required for a solar eclipse?

The phase of the Moon must be new, and the nodes of the Moon's orbit must be nearly aligned with Earth and the Sun.

Which of the following best describes why we have seasons on Earth? 1. The tilt of Earth's axis causes different portions of Earth to receive more or less direct sunlight at different times of year. 2. Earth's elliptical orbit means we are closer to the Sun and therefore receive more intense sunlight at some times of year than at others. 3. The varying speed of Earth in its orbit around the Sun gives us summer when we are moving fastest and winter when we are moving slowest. 4. The tilt of Earth's axis causes the Northern Hemisphere to be closer to the Sun than the Southern Hemisphere in summer, and visa versa in winter.

The tilt of Earth's axis causes different portions of Earth to receive more or less direct sunlight at different times of year.

So what is the cause of the seasons?

The tilt of Earth's axis causes different portions of the Earth to receive more or less direct sunlight at different times of year.

which statement best describes how variation in the Earth-Sun distance affects the seasons?

The variation in Earth-Sun distance over the course of each year has virtually no effect on the seasons.

Chose the correct explanation why the statement makes sense (or is clearly true) or does not make sense (or is clearly false). 1. This statement makes sense, we can see through the band of light we call the Milky Way to external galaxies, and the binoculars are sensitive enough to view them even through the dark fissure of gas and dust blocking our view. 2. This statement does not make sense, because we cannot see through the band of light we call the Milky Way to external galaxies; the dark fissure is gas and dust blocking our view. 3. This statement makes sense, we can see through the band of light we call the Milky Way to external galaxies, as nothing is blocking our view. 4. This statement does not make sense, we can see through the band of light we call the Milky Way to external galaxies, but we need more sensitive equipment, than binoculars.

This statement does not make sense, because we cannot see through the band of light we call the Milky Way to external galaxies; the dark fissure is gas and dust blocking our view.

The Moon and the Sun are approximately the same angular size. True False

True

Rank the seasons for the Northern Hemisphere based on Earth's distance from the Sun when each season begins, from closest to farthest.

Winter Spring Fall Summer

Which of the following correctly describes the meridian in your sky? 1. the point directly over your head 2. the boundary between the portion of the celestial sphere you can see at any moment and the portion that you cannot see 3. a half-circle extending from your horizon due east, through the north celestial pole, to your horizon due west 4. a half-circle extending from your horizon due east, through your zenith, to your horizon due west 5. a half-circle extending from your horizon due north, through your zenith, to your horizon due south

a half-circle extending from your horizon due north, through your zenith, to your horizon due south

If the Moon is setting at 6 A.M., the phase of the Moon must be

full

If the Sun rises precisely due east,

it must be the day of either the spring or fall equinox.

Suppose you live at a mid-latitude in the Southern Hemisphere (such as in Australia, New Zealand, Chile, or South Africa). When will you have 12 hours of daylight and 12 hours of darkness?

on both the March and September equinoxes

Orion is visible on winter evenings in the northern hemisphere but not summer evenings because of

the location of Earth in its orbit.