Astronomy
Chapter 9 Homework
Homework
Scholars Online Astronomy - Chapter 9: The Earth as a Planet
Homework
- Reading Preparation
- Key Formulae to Know
- WebLecture
- Study Activity
- Chat Preparation Activities
- Chapter Quiz
- Lab Work
Reading Preparation
Reading: Astronomy, Chapter 9: The Living Earth
Study Notes: notes on your assigned reading from the text
- 9.1 Energy from the sun drives thermal currents in the atmosphere and oceans; pressure from tidal warping due to the moon's gravitational pull, and pressure on the Earth's core, drive thermal currents in the magma and core of the Earth's interior. The composition of the atmosphere determines how the planet receives and retains energy radiated from the sun.
- 9.2 Earthquakes generate S waves and P waves, which together give us clues to the earth's internal structure. The theory of plate tectonics can be used to account for the formation of multiple and dissimilar characteristics. Note the struggle the theory went through for acceptance: without direct evidence, it was very difficult for its proponents to convince their colleagues that it was a viable theory. Ultimately, satellite measurements provided data supporting the movement of the plates. Note how the no-oceans view of the earth's surface compares to Venus and Mars!
- 9.3 Plate movements and pressure at plate edges generate earthquakes and volcanic activity.
- 9.4 In addition to its other physical characteristics, the earth has a very strong magnetic field which interacts with the "solar wind", the flow of materials from the sun (gas, ionized particles), effectively protecting life on earth from dangerous particles. Fluctuations in the solar wind can change the shape of the magnetic field.
- 9.5 Earth's atmosphere has changed through its history, most notably in the acquisition of oxygen from organic sources.
- 9.6 The Earth's atmosphere circulates constantly, driving by solar heat and convection currents, in layers that differ in density, composition, and temperature.
- 9.7 Human populations use resources and produce wastes in sufficient quantities to affect the natural balances in the atmosphere, oceans, and land surfaces.
Also note life forms create changes in the earth's surface (and not just human life: consider the erosion capabilities of plants and the ability of beavers to completely change their environments in very short time periods!)
Key Formulae to Know
No New formulae!
Web Lecture
Read the following weblecture before chat: The Earth
Study Activity
Viewing Earth from above:
- Use Google Earth to explore the Earth's surface. Chose Google Earth on web to run it in your browser, then "Launch Earth." Google loads cloud cover in real time based on NOAA data.
- Once you have located Earth in your screen, use the Google Earth controls to explore the surface, and note how sunlight affects the poles at this time of year (you may need to set "Sun" on in the View Menu). If you are doing this exercise around Thanksgiving, the northern hemisphere is approaching midwinter, so the north pole will be in darkness, and the south pole -- Antarctica -- will be in sunlight, regardless of the time of day.)
- Look up the following surface features:
- Barringer Crater (Meteor Crater Natural Landmark)
- Grand Canyon of the Colorado (river erosion)
- Mt. Rainier and Mt. St. Helens (volcanoes)
- Marianas Trench and Pacific floor
- Pacific Ocean side of Earth (from far enough out to see entire planet)
- Use the Earth's Currents website to explore atmospheric and oceanic currents.
- The default setting is for wind currents. View the Earth from different angles and compare the wind patterns with the cloud patterns seen on Google Earth.
- Click on Earth in the lower left and reset the display for Ocean Currents. How are these related to the wind currents you viewed earlier? To the storm centers on Google Earth? How does solar energy propel these currents/
UNL Tools Exercises
- Interactives:
- Use the Seasons interactive tasks to review Earth-based season dependence on Earth's tilt and sunlight.
Optional Website Viewing the earth as one of several planets with similar characteristics offers us a new perspective. The University of Washington's astronomy department offers courses on planetary atmospheres, planetary surfaces, and the origin of the solar system. Take a look at the topics discussed for these courses.
Study the Perpetual Ocean video ==>HERE<==. You can view (and download) either the 3-minute or full 20-minute version. Pay close attention to the patterns that develop and change over time.
Chat Preparation Activities
- Essay question: The Moodle forum for the session will assign a specific study question for you to prepare for chat. You need to read this question and post your answer before chat starts for this session.
- Go over the list of Key Words and Key Ideas at the end of the chapter. If you don't remember the definition of the key word, review its use (the page number on which it is explained is given).
- Read through the Review Questions and be prepared to discuss them in class. If any of them confuses you, ask about it!
- Mastery Exercise: The Moodle Mastery exercise for the chapter will contain sections related to our chat topic. Try to complete these before the chat starts, so that you can ask questions.
Chapter Quiz
- Required: Complete the Mastery exercise with a passing score of 85% or better.
- Go to the Moodle and take the quiz for this chat session to see how much you already know about astronomy!
Lab Work
Read through the lab for this week; bring questions to chat on any aspect of the lab, whether you intend not perform it or not. If you decide to perform the lab, be sure to submit your report by the posted due date.
- Lab instructions:: Rock Identification
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