Mastering Astronomy Homework 4
Which of the following statements are true about summer compared to winter?
-The Sun follows a longer and higher path through your sky in summer - You have more daylight and less darkness in summer. - Temperatures tend to be warmer in summer.
Based on what you have learned from your rankings in Parts A and B, why is it generally hotter in summer than in winter?
-The Sun is higher in the sky in summer -We have more hours of daylight in summer.
The Sun reaches the zenith (directly overhead) at midday ___________.
-on the equator only on the March and September equinoxes -everywhere within the tropics (between latitudes 23.5°N and 23.5°S) on two dates each year
Which position in this diagram represents Earth on the day that we have the longest amount of daylight in the continental United States?
2
Which position in this diagram represents Earth at the beginning of spring for the Southern Hemisphere?
3
What is the basic reason that we have seasons on Earth?
Earth's axis is tilted relative to the ecliptic plane.
Where does the Sun remain above the horizon all day (never setting) on the December solstice?
Everywhere between the Antarctic Circle (latitude 66.5°S) and the South Pole
The following figures are the same as those from Part A. This time, imagine that each person places an identical glass of water outside. Consider only the effects of the season — meaning the amount of daylight and the height of the Sun's path through the sky — on the water temperature. Rank the figures based on the highest (warmest) temperature the glass of water would reach during a 24-hour period, from highest to lowest. To rank items as equivalent, overlap them.
Highest Temperature: 3rd, 4th, 5th pic Middle: 1st, 2nd, 6th pic Lowest Temperature: none
How does Earth's varying distance from the Sun affect our seasons?
It doesn't; Earth's orbital distance plays no significant role in the seasons.
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.
What is special about the June solstice?
It's the day on which the Northern Hemisphere receives its most direct sunlight.
Which of the following planets has essentially no seasons at all?
Jupiter (axis tilt = 3.1°)
Based on what you have learned from your rankings in Parts A and B, which of the following planets would you expect to have seasons most like Earth's?
Mars (axis tilt = 25.2°)
Each of the following figures shows a person (not to scale) located on Earth at either 40°N or 40°S latitude. Rank the figures based on how much time the person spends in daylight during each 24-hour period, from most to least. To rank items as equivalent, overlap them.
Most Daylight: 3rd, 4th, 5th pic Middle: 1st, 2nd, 6th pic Least Daylight: none
In spring, the axis points toward
Polaris
Suppose Earth's axis tilt was significantly greater than its current 23.5 degrees, but Earth's rotation period and orbital period were unchanged. Which statement below would not be true?
The length of each season (for example, the number of days from the summer solstice to the fall equinox) would be significantly longer than it is now.
Which of the following best describes why we have seasons on Earth?
The tilt of Earth's axis causes different portions of the Earth to receive more or less direct sunlight at different times of year.
You've now seen that Earth's varying distance cannot be the cause of our seasons. 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.
Based on what you have learned from your rankings in Parts A and B, 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.
Which of the following planets should have the most extreme seasons?
Uranus (axis tilt = 97.9°)
If the Sun rises precisely due east,
it must be the day of either the March or the September 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
The Sun's path, as viewed from the equator, is highest in the sky on _________.
the March and September equinoxes
If our year were twice as long (that is, if Earth took twice as many days to complete each orbit around the Sun), but Earth's rotation period and axis tilt were unchanged, then _________.
the four seasons would each be twice as long as they are now
When it is summer in Australia, the season in the United States is
winter
