Chapter 8: Astronomy

Sections in this Chapter

Chapter Challenge
Section 1: The Size and Scale of the Universe
Section 2: Locating Astronomical Objects in the Night Sky
Section 3: Origin of the Universe
Section 4: Orbits and Effects
Section 5: The Sun-Earth-Moon System
Section 6: Impact Events and the Earth System
Section 7: The Electromagnetic Spectrum
Section 8: The Sun and its Effects
Section 9: The Lives of Stars

Chapter Challenge

In this section you will find materials that support the implementation of EarthComm, Chapter 8: Chapter Challenge.

Earth’s Location

The Cosmic Distance Scale, NASA
This resource gives an impression of how immense our Universe is by starting with an image of the Earth and then zooming out to the furthest visible reaches of our Universe.

The Formation of Earth’s Solar System

The Origin of the Solar System, Royal Museum Grenwich
Read an outline of different theories for the formation of the solar system.

The Sun’s Influence on the Earth

Climate and Earth’s Energy Budget, NASA Earth Observatory
An in-depth article on Earth’s energy budget.

The Sun’s Composition and Structure

A Look Inside Our Nearest Star!, Montana State University
Find out more about the interior structure of our nearest star. This page features a brief introduction with links to separate pages on different parts of the sun.

The Structure of the Sun, NASA
Read this in-depth description of the Sun’s structure.

How the Sun Compares to Other Stars

What are the main differences between the sun and other stars?, Windows to the Universe
Looks at the factors that cause stars to be different, such as mass, size, temperature, and age.

How Does Our Sun Compare to Other Stars, NASA Space Place
Compares the intrinsic brightness of the Sun to other stars.

Orbit of the Earth and Moon

Our Restless Tides, NOAA, CO-OPS
Get an explanation of the basic astronomical factors which produce tides and tidal currents.

Lunar Tides, NASA
Look at how the Earth also has a tidal effect on the Moon.

Ask an Astrophysicist, NASA
How does the Earth’s tilt affect the changing of the seasons, and what different angles cause those different seasons?

Precession, NASA
Learn how the north star can change as the Earth wobbles on its axis.

Comets and Asteroids

Hazards: Meteors and Asteroids, NASA
Historical perspective of asteroid impact research and planetary defense strategies.

Asteroids and Comets, National Geographic
Defines asteroids and comets and explains where they are located.

Questions and Answers Regarding Near-Earth Asteroids, Jet Propulsion Laboratory
Get some facts about whether asteroids are a risk to people on Earth.

Near Earth Objects, International Astronomical Union
Examine data and information on asteroids and other celestial bodies that approach Earth.

Sample Podcasts

Hubblecast, The Hubble Space Telescope
Video podcasts showcasing Hubble Telescope research and findings. Audio portions are good examples of podcasts students should try to create.

Earth Audio and Video Podcasts, NASA
Podcasts on Earth related topics. Click on images that accompany podcasts for written transcripts.

Science Friday, Science Friday
A weekly podcast on a variety of science topics.

Science in Action, BBC
Podcasts on science related topics.

Section 1: The Size and Scale of the Universe

Learning Outcomes

Develop a scale model of the solar system.
Evaluate different scale models and compare their strengths and limitations.
Use mathematics to calculate distances to objects in the universe in astronomical units (au), light-years, and parsecs (pc).

Using Technology

To learn more about the distances in space, complete the following:

Distances between Stars and Galaxies

Astronomers use sky maps to map the stars and describe their locations. You will use a software program called Google Earth to explore a sky map. Using a computer with an internet connection, open Google Earth. If your computer does not have Google Earth installed, go to http://earth.google.com/ to download a free version.
Click the icon on the toolbar to choose Sky. You will see a view of the sky from your location on the Earth. White dots represent stars on the sky map.
Using the Google Earth navigation controls, locate 10 stars on the sky map. Click on the white dot for each star to retrieve descriptive information about the star.
1. Create a table that lists the name and distance of each star.
2. What are the closest and farthest stars you located? How do their distances compare to the distance of Proxima Centauri? How do they compare to the distance of the Andromeda Galaxy?

Inquring Further

To learn more about solar-system walks, visit the following web sites:

Build a Solar System Walk, Exploratorium
Make a scale model of the Solar System and learn the REAL definition of “space.”

Voyage: A Journey Through the Solar System along the National Mall in Washington DC, National Center for Earth and Space Science Education
Planning a visit to the nation’s capital? If so, check out a lesson related to the scale model of the solar system along the National Mall. For more information, read this article about the exhibit in Smithsonian magazine. To learn more about the five stars nearest to the Sun, visit the following web sites:

The Nearest Star, NASA
Learn how far Proxima Centauri is from Earth, as well as how astronomers calculate distances to stars.

The 26 Nearest Stars to Earth, University of Wisconsin
Examine a list of the closest stars to Earth.

The Nearest Stars: a Guided Tour, The Astronomical Society
A tour through the stellar neighbourhood.

General Resources

To learn more about this topic, visit the following web sites:

Astronomical Unit (AU), Near Earth Object Program, NASA
Find out more about the Astronomical Unit.

What is a light year and how is it used? Starchild, NASA
This description is similar to the text in EarthComm but also offers links to other relevant pages.

If a Millimeter Were a Year/Light-Year, Kelley L. Ross
Comprehending a distance as great as a light year is difficult. This brief essay puts the light-year in perspective by comparing it to a millimeter.

Animations and Video

To view animations and video related to this topic, visit the following web sites:

Milky Way, NASA
Take an interactive tour of the Milky Way (Flash needed).

Launchpad: New Horizons Covers the Distance, NASA
Locate and watch the NASA eClip titled, “Launchpad: New Horizons Covers the Distance.” This video explains how scientists use astronomical units to measure large distances in space.

Section 2: Locating Astronomical Objects in the Night Sky

Learning Outcomes

Develop a model for identifying specific locations on Earth.
Analyze a coordinate system as a mathematical model for locating objects in the sky.
Identify patterns in the organization and distribution of matter in the universe.

Using Technology

To learn more about locating objects in space, complete the following:

Exploring the Celestial Sphere

In the previous section, you examined a sky map using the Google Earth software program. Google Earth enables you to explore the celestial sphere using a coordinate system. You can also look into the night sky and observe astronomical objects from various directions and from different locations on the Earth’s surface. Using a computer with an internet connection, open Google Earth. If your computer does not have Google Earth installed, go to http://earth.google.com/ to download a free version.
Under the “Fly To” tab in the “Search” panel, type in the name of your town or city and state and then click the hand icon. Google Earth will zoom into your location.
Click the thumb tack icon on the toolbar to put a placemark on your location. Insert the name of your location and make a note of its longitude and latitude.
Click the planet icon on the toolbar and select “Sky.” In the “Places” panel click on your location. Use the zoom slider navigation control to zoom out from your location. You should now see a view of the night sky from your location on the Earth.
a. Describe what you see.
b. What constellations are visible from this location?
Return to a view of the Earth by clicking on the planet icon and selecting “Earth.”
Determine the location in the southern hemisphere that is exactly opposite your own. Use the navigation controls and lines of longitude and latitude to help you find this location. Click the thumb tack icon on the toolbar to put a placemark on this location. Give this location a name.
Return to a view of the sky by clicking on the planet icon on the toolbar and selecting “Sky.” Use the zoom slider navigation control to zoom out from your new location. You should now see a view of the night sky from your new location.
a. How does the view from your southern hemisphere location compare to the view from your northern hemisphere location?
b. What constellations are visible from this location?
Chose four other places on Earth and explore the night sky from each. Record the constellations visible from each location.
Return to a view of the Earth. Go to where the Prime Meridian intersects the Equator. Placemark this location and record its coordinates. View the night sky from this location.
a. What do you notice about the values of the celestial sphere grid coordinates at this location?
Lines comparable to latitude on Earth are called declination on the celestial sphere. Positions north of the celestial equator are called plus declination and are measured in degrees. Positions south of the celestial equator are called minus declination and are also measured in degrees. The lines that correspond to longitude on Earth are called right ascension. Right ascension is measured from the point where the Sun crosses the celestial equator about March 21 (the vernal equinox). Right ascension is measured in hours, minutes, and seconds, moving eastward from the vernal equinox. Use the navigation controls to go locate the place in the night sky where the declination and right ascension have zero values.
a. What is the closest star to this position?
Using the navigation controls, orient the celestial sphere towards the north celestial pole. Find Polaris, the North Star, and record its coordinates and the name of its constellation.
Using the navigation controls, orient the celestial sphere towards the south celestial pole. Find the Southern Star and record its coordinates and the name of its constellation.
In the “Layers” panel, click on “Featured Observatories.” In the sky view, click on the “Featured Observatories Introduction.” This should bring you to a list of programs and satellites used by scientists to research astronomical objects and celestial phenomena. Learn more about each observatory by clicking on its name.
Use the “Featured Observatories” to explore the Universe. Find and record the names, coordinates, and the nearest constellation for the following:
a. Two different types of galaxies
b. A black hole
c. A super nova
d. A gamma burst
e. The largest star in the Milky Way Galaxy
f. A region with new stars being born
In the “Layers” panel, click on “Our Solar System.” In the sky view, go to the “Solar System Introduction.” Follow the directions provided for finding the location of a planet at a particular time. Find and record the coordinates and the nearest constellation for the following:
a. Jupiter today
b. Jupiter one week from today
c. The Moon today
d. The Moon one week from today

Inquring Further

To learn more about Earth’s axial tilt and the position of Polaris, visit the following web sites:

Polaris, Lunar and Planetary Institute Provides information about Polaris, including the effect of the wobble of Earth’s axis.

Milankovitch Cycles and Glaciation, Indiana University
Provides information on variations in the Earth’s eccentricity, axial tilt, and precession.

Precession, NASA
Learn how the north star can change as the Earth wobbles on its axis. To learn more about how to use star charts, visit the following web sites:

Your Sky Tonight, PBS
Create a star chart set for your time and location.

The Night Sky This Month, Emil Neata
Learn where to locate planets, comets and meteors in the night sky.

This Week’s Sky at a Glance, Sky and Telescope
Learn more about daily events in the changing sky.

Astronomy: Your Sky Tonight, EarthSky
Enter your zip code to bring up a star chart of your local area. To learn more about constellations , visit the following web site:

The Constellations, International Astronomical Union
A comprehensive list of the 88 defined constellations with official spellings and abbreviations.

General Resources

To learn more about Astronomical Objects, visit the following websites:

The Celestial Sphere, NASA
Learn how the sphere of the sky has two points around which it turns, points that mark its axis - the celestial poles.

Changes in Star Positions, NASA
Find out why stars seem to travel across the sky at night differently than the moon moves?

Video: Using Star Charts and Star Wheels, Cradle of Aviation Museum
Video that explains how to use sky charts and star wheels.

Section 3: Origin of the Universe

Learning Outcomes

Use a model to show the relationship between a moving object and the energy it emits.
Use a model to predict the direction and rate of movement of galaxies in the universe.
Analyze data to determine patterns in electromagnetic radiation that fills the universe.
Use a model explain the nebular theory of the formation of the solar system.
Examine the evidence that supports the big bang theory for how the universe was formed.

Using Technology

To learn more about extrasolar planets, complete the following:

Planets Outside of Our Solar System

Over the past decade, scientists have made incredible discoveries of planets outside of our solar system. These planets are known as extrasolar planets or exoplanets. Visit NASA’s Planet Quest website at http://planetquest.jpl.nasa.gov/.
1. What is the current exoplanet count?
Go to the New Worlds Atlas on the website and examine the list of all extrasolar planets. Click on the “Disc. Date” column heading to organize the list of planets from most recent to earliest discovered.
1. How many planets have been discovered in the past month?
2. How many planets have been discovered in the past year?
Click on the “Light-years from Earth” column heading to organize the list of planets from closest to farthest.
1. What is the name of the closest planet discovered so far? How far away is it?
2. What is the name of the farthest planet discovered so far? How far away is it?

Inquring Further

To learn more about nuclear fusion, visit the following web sites:

Fusion Basics, Princeton Plasma Physics Laboratory
Get started learning about fusion with this brief video of how fusion works.

How EINSTEIN Arrived at E=MC², Mort Orman, M.D.
Learn how Albert Einstein came upon his famous equation. To learn about particle accelerators, visit the following websites:

The Large Hadron Collider, CERN
Learn about the world’s largest and most powerful particle accelerator.

RCW 86: Natures Super Particle Accelerator, NASA
Read about how a supernova acts as a particle accelerator.

To learn more about cosmic background radiation, visit the following web sites:

Tests of the Big Bang: The CMB, NASA
Describes how the universe is filled with radiation left over from the Big Bang, called the “cosmic microwave background”.

To learn more about star-forming nebulae in the galaxy, visit the following web sites:

The Hubble Project, NASA
Learn how the Hubble Space Telescope has helped advance our understanding of space, including star-forming nebulae.

Hubble Telescope, Space Telescope Science Institute
Find out more information about star formation on the Hubble Site.

European Southern Observatory Look through the website of the European Southern Observatory to find more information on star formation.

Early Star Formation, ScienceDaily
Read a brief article about what scientists understand about star formation.

Birth of a Star, New York Times
Animation of the life of a young star. To learn more about extrasolar planet research missions, visit the following web site:

Exoplanet Missions, NASA
This site lists all of NASA’s missions conducting extrasolar planet research.

General Resources

To learn more about each topic, visit the following websites:

The Nebular Theory

Solar System Formation, University of Nebraska-Lincoln
This site has a diagram of the formation of the Solar System.

The Solar Nebular Hypothesis, NASA
Read an approximate chronology of the formation of the solar system through to the origin of life on Earth.

The Birth of the Planets

Discovery of a 6-Planet Solar System CNN
A video about a discovery in 2023.

How the Solar System was Born, , Natural History Museum London
Learn about the time after the gravitational collapse of the solar system.

Ask the Astronomer, Dr. Sten Odenwald
Find out answers to different questions about our galaxy and others.

Milk Way Images

Multiwavelength Astronomy, NASA’s Infrared Astrophysics Data Center
View all-sky maps that portray the entire Milky Way Galaxy.

Astronomy Pictures of the Day: Milky Way Galaxy, Goddard Space Flight Center
Examine images and pictures of the Milky Way Galaxy.

To view animations and video related to this topic, visit the following web sites:

NASA, Space Telescope Science Institute
View a video of deep space as taken by the Hubble Space Telescope. See images of the Universe closer to the time when it formed.

Launchpad: The Search for Exoplanets, NASA
Locate and watch the NASA eClip titled, “Launchpad: The Search for Exoplanets.” This video examines extrasolar planet research efforts.

Launchpad: Kepler, NASA
Locate and watch the NASA eClip titled, “Launchpad: Kepler.” This video examines the efforts of the Kepler Mission to locate Earth-sized and smaller planets.

Section 4: Orbits and Effects

Learning Outcomes

Use mathematics to develop models that explain patterns in the orbits of planets in our solar system.
Analyze data to identify the relationship between the shape of a planet’s orbit and its distance from the Sun.
Obtain information about Kepler’s laws and how they explain planetary motion.

Inquring Further

To learn more about the gravitational “slingshot” effect, visit the following web site:

Galileo Overview, NASA
Learn a little more about how the Galileo spacecraft used the gravitational fields of Earth and Venus to propel itself into space towards Jupiter. There is also a helpful diagram of its path over time.

To learn more about the orbits of comets and asteroids, visit the following web sites:

The Comet’s Tail: Comet Orbits, Univ. of California Berkeley
Learn how orbits are determined. Also examine the factors that affect a comet’s orbit as well as how we know a comet is in its predicted orbit.

Orbits, Near Earth Object Program, NASA
Enter the name of any asteroid or comet, and a 3D orbit visualization tool will appear for that object. You can also select from the list of Potentially Hazardous Asteroids to see the asteroids orbit in relation the orbits of Earth and other planets in the solar system.

General Resources

To learn more about each topic, visit the following websites:

Eccentricity

Kepler’s Laws, HyperPhysics
Check out these diagrams and charts to help understand Kepler’s Second Law.

Axial Tilt (Obliquity)

Ask an Astrophysicist, NASA
How does the earth’s tilt affect the changing of the seasons, and what different angles cause those different seasons?

Milankovitch Cycles and Glaciation, Indiana University
Learn about the connection between eccentricity, axial tilt, and precession in relation to past glaciations.

Precession

Precession, NASA
This article describes the development and background behind the idea of precession.

Inclination

Solar System Exploration, NASA
A profile of various statistics for each planet.

The Moon’s Orbit and Eclipses, NASA
Learn how orbital geometry controls the timing of lunar eclipses.

Section 5: The Sun-Earth-Moon System

Learning Outcomes

Use a model to explain the relative motions of Earth, the Moon, and the Sun.
Carry out an investigation that examines the changes in the appearance of the Moon in the night sky.
Analyze and interpret data to determine the relationship between the motion of the Moon and coastal tides.
Use mathematics to calculate how Earth’s rotation has changed over time due to tidal forces.
Obtain information about the formation of Earth and the Moon.

Using Technology

To learn more about tides, complete the following:

Tides and Lunar Phases

Table 1 in the Student Edition shows data from the month of January 2009. Obtain tidal data during the same period that you are doing your Moon observations. Select several cities nearest your community. a. Record the highest high tide and the lowest low tide data for each city. Choose at least eight different days to compare. Correlate these records to the appearance of the Moon during your observation period. Make a table like Table 1 showing high and low tides for each location. b. What do you notice about the correlation between high and low tides and the appearance of the Moon?

To find tidal data for several different cities, visit the following web sites:

Tidal Current Predictions, NOAA

Tides and Currents Data, NOAA

IMPORTANT: Please review the following information to help understand the tidal prediction data. Or try the following pages on the NOAA - Center for Operational Oceanographic Products and Service :

Tides and Currents Education

What formats are tide predictions available in?

Standard Format - This format is available in hard copy and an electronic, ASCII file which provides time and height of tide information for a single location in a page readable format. The following example for EASTPORT, ME, April, 1997 shows the predictions in AM/PM Time and has been adjusted for Daylight Savings Time.

Eastport, Maine T.M. 75 W.
Tide Predictions (High and Low Waters) April, 1997
NOAA, National Ocean Service

Standard Time

Day	Time	Ht.
1 Tu	428am	H 18.6	1101am	L 0.7	504pm	H 17.8	1128pm	L 1.5
2 W	532am	H 18.8	1204pm	L 0.4	608pm	H 18.2
3 Th	1233am	L 0.9	636am	H 19.2	107pm	L -0.2	711pm	H 19.0
4 F	136am	L 0.0	739am	H 20.0	207pm	L -1.1	810pm	H 20.1
5 Sa	235am	L -1.2	838am	H 20.9	304pm	L -1.9	906pm	H 21.1

Example for EASTPORT, ME, April-June, 1997.
Please Note:** All heights are in feet.

How accurate are the predictions?

The accuracy of the tide predictions is different for each location. Periodically we do a comparison of the predicted tides vs the observed tides for a calendar year. The information generated is compiled in a Tide Prediction Accuracy Table. We work to insure that the predictions are as accurate as possible. However, we can only predict the astronomical tides, we cannot predict the effect that wind, rain, freshwater runoff, and other short-term meteorological events will have on the tides.

In general, predictions for stations along the outer coast are more accurate than those for stations farther inland; along a river, or in a bay or other estuary. Inland stations tend to have a stronger non-tidal influence; that is, they are more susceptible to the effects of wind and other meteorological effects than stations along the outer coast. An example of an inland station which is difficult to predict is Baltimore, Maryland. This station is located at the northern end of Chesapeake Bay. Winds which blow along the length of the bay have been known to cause water levels to be 1-2 feet above or below the predicted tides.

Stations in relatively shallow water, or with a small tidal range, are also highly susceptible to meteorological effects and thus difficult to accurately predict. At these stations, short-term weather events can completely mask the astronomical tides. Many of the stations along the western Gulf of Mexico fall into this category. An example is Galveston, Texas. This station is in a bay which is relatively shallow and has a small opening to the sea. At this station it is possible for meteorological events to delay or accelerate the arrival of the predicted tides by an hour or more.

Inquring Further

To learn more about why the Earth has two tidal bulges, visit the following web sites:

Tides Online, NOAA
Access current tide information.

Sea Science: Rolling with the Tide: Sun, Moon and Raven, North Carolina SeaGrant
Learn more about why the Earth has two tidal bulges instead of just one. To learn more about tidal forces throughout the solar system, visit the following web sites:

Jupiter: Moons: Io, NASA
Compare the tides on Io to Earth.

High Tide on Io, NASA
Information on Io and its tides.

Exploring Tidal Forces: Black Holes and Saturn’s Rings, NASA
Why do planets have rings? Find out about the connection between rings and tidal forces. To learn more about impact craters throughout the solar system, visit the following web sites:

Finding Impact Craters with Landsat, NASA
Get more information about impact craters on Earth and the moon.

Impact Craters on the Planets, Lunar and Planetary Institute
Check out images of impact craters on Mercury, Venus, the Moon, Jupiter’s moon, Ganymede, Saturn’s moon, Dione, and Uranus’ moon, Miranda.

To learn more about Isaac Newton’s discoveries and inventions, visit the following web sites:

Isaac Newton’s Discoveries and Inventions, Newton Online
Read about how Isaac Newton’s discoveries and inventions widened the reaches of human thought and demonstrated the power of the scientific way of thinking.

General Resources

To learn more about each topic, visit the following websites:

The Formation of the Earth and Moon

Age of the Earth, USGS
Find out more about what scientists believe how and when the Earth formed.

The Formation of the Earth’s Moon, NASA
Learn about the restrictions theories for the formation of the moon must account for, why some theories work, and why some do not work.

Tides

Our Restless Tides, NOAA, CO-OPS
Explains the basic astronomical factors which produce tides and tidal currents.

High Tides and the Full Moon,, Dutton Institute
Learn about high tides and the lunar cycle.

Lunar Tides, NASA
Look at how the Earth has a tidal effect on the Moon.

Animations and Video

To view animations and video related to this topic, visit the following websites:

Launchpad: Solar Eclipses, NASA
Locate and watch the NASA eClip titled, “Launchpad: Solar Eclipses.” This video examines the unique geometry of the Sun-Earth-Moon system that creates eclipses.

Launchpad: Newton’s Laws On-Board the International Space Station, NASA
Locate and watch the NASA eClip titled, “Launchpad: Newton’s Laws On-Board the International Space Station.” This video examines Newton’s Laws of Motion and applies the laws to certain situations experienced by astronauts on the International Space Station.

Launchpad: Moon Magic, NASA
Locate and watch the NASA eClip titled, “Launchpad: Moon Magic.” This video examines the Moon’s orbit, including its effects on tides.

Section 6: Impact Events and the Earth System

Learning Outcomes

Use mathematics to explain the energy released when asteroids or comets collide with Earth.
Use computational thinking to compare impact events.
Obtain information about the probability and effects of asteroid, comet, and meteorite collisions with Earth.

Inquring Further

To learn more about impact craters on objects other than Earth, visit the following web sites:

Asteroids and Early Earth History, Exploratorium Magazine Online
Read a little more about how impact craters form and what they reveal.

Finding Impact Craters with Landsat, NASA
Lesson on finding impact craters on Earth and the moon.

To learn more about how scientists map Earth-approaching asteroids, visit the following web sites:

Questions and Answers Regarding Near-Earth Asteroids, Jet Propulsion Laboratory
Get some facts about whether asteroids are a risk to people on Earth.

Relative Positions Of Asteroids Near Earth, NASA
Check out this map showing asteroids near Earth. To learn more about Barringer Crater, visit the following web sites:

Barringer Crater (Meteor Crater) Learn more about how the Barringer Crater came to be recognized as a meteor impact crater.

Barringer Meteor Crater and Its Environmental Effects, Lunar and Planetary Institute
A short article on the formation of this impact crater and its likely effects on the environment at the time.

General Resources

To learn more about each topic, visit the following websites:

Asteroids

Asteroid Fact Sheet, National Space Science Data Center at Goddard Space Flight Center
Check out a list of numerous asteroids with a data set for each.

What Are Asteroids? National Space Science Data Center at Goddard Space Flight Center
Read a detailed description of asteroids, the different types of asteroids, and where asteroids are located in the solar system.

Comets

Comet Fact Sheet, National Space Science Data Center at Goddard Space Flight Center
Check out this list of numerous comets with a data set for each.

Meteoroids, Meteors, and Meteorites

Frequently Asked Questions About Meteors and Meteorites, American Meteor Society
Curious to know answers to some commonly asked questions? If you don’t understand the answer given, they invite you to contact them for clarification.

Division of Meteorites, National Museum of Natural History - Smithsonian
What is a meteorite? How do you recognize a meteorite if you have one? Find out the answers to these questions plus get information about additional resources.

To see more images of Asteroid Ida and her moon, visit the following web site:

Asteroids, National Space Science Data Center Photo Gallery
See images of several different asteroids, including Ida and its moon, Dactyl.

To see more images of Halley’s Comet, visit the following web sites:

Giotto Mission Page, National Space Science Data Center Photo Gallery
See images of Halley’s Comet taken by Giotto when the comet last past Earth in the 1980s.

Comets, National Space Science Data Center Photo Gallery
See some images of several different comets, including Halley.

Animations and Video

To view animations and video related to this topic, visit the following web site:

Our World: Stardust, NASA
Locate and watch the NASA eClip titled, “Our World: Stardust.” This video examines meteorites and comets.

Section 7: The Electromagnetic Spectrum

Learning Outcomes

Carry out an investigation of the visible part of the electromagnetic spectrum.
Analyze and interpret data on the frequencies of the electromagnetic spectrum.
Obtain information about how astronomers use electromagnetic radiation to study objects and events in space.

Inquring Further

To learn more about using radio waves to study distant objects, visit the following web site:

Radio Observatories and the Very Large Array, National Radio Astronomy Laboratory
Find out how scientists study distant objects using the VLA and radio waves.

Very Large Array: FAQ, National Radio Astronomy Laboratory
Learn more about the VLA.

To learn more about detection of electromagnetic radiation, visit the following web sites:

How Landsat Works, NASA
Learn how sensors and detectors are used to detect and measure electromagnetic radiation in different bands.

The Very Large Array and the Very Long Baseline Array, National Radio Astronomy Observatory
Read about the radio telescope arrays that allow scientists to look deep into space. To learn more about technologies that use electromagnetic radiation, visit the following web sites:

Invention of the Microwave, History.com
Learn more about the history and technology of the microwave oven.

How does an X-ray machine work?, Howstuffworks
Learn how an x-ray machine produces x-rays.

General Resources

To learn more about each topic, visit the following websites:

The Nature of Electromagnetic Radiation

The Electromagnetic Spectrum, NASA
This home page offers links to various topics in the astronomer’s toolbox.

All About Spectra, University of Illinois
Try another brief overview on electromagnetic spectrum and electromagnetic wave radiation.

Astronomy and the Electromagnetic Spectrum

An Introduction to Radio Astronomy, National Radio Astronomy Observatory
The NRAO web site offers an education section with various resources including background information and a photo gallery. The Introduction to Radio Astronomy is a particular page that offers answers to frequently asked questions about radio astronomy, an article about the VLA and VLBA in New Mexico, and more.

Using Electromagnetic Radiation to Understand Celestial Objects

Amazing Space, Space Telescope Science Institute
Explore space with the Hubble Telescope. Learn what different colors say about stars by clicking on Star Light, Star Bright.

Animations and Video

To view animations and video related to this topic, visit the following web sites:

Launchpad: Neon Lights - Spectroscopy in Action, NASA
Locate and watch the NASA eClip titled, “Launchpad: Neon Lights - Spectroscopy in Action.” This video examines emission spectrums and absorption spectrums and their application to objects in space.

The Electromagnetic Spectrum Video Series & Companion Book, NASA
Follow links to videos on a variety of topics related to the electromagnetic spectrum.

Section 8: The Sun and its Effects

Learning Outcomes

Analyze and interpret sunspot and solar flare data.
Obtain information about solar activity and its effects.

Inquring Further

To learn more about daily solar activity, visit the following web sites:

What’s Up in Space, Spaceweather
Get the most recent information about solar flares, sunspots, and coronal holes.

Solar Terrestrial Activity Report, GFZ Potsdam
Check out the most recent sun spot data.

The very latest SOHO images, The Solar and Heliospheric Observatory - NASA
See some of the most recent images of the sun. To learn more about the auroras, visit the following web sites:

’tis the Season for Auroras, EarthSky
Autumn is a good time to spot Northern Lights, and scientists would like to know why.

Auroras - Paintings in the Sky, Exploratorium
This site will show you what auroras look like on Earth and from space, explain how they are created, and show you where they can be found. Teach yourself using the “Self-Guided Lesson” button. To learn more about solar radiation and airplane passengers, visit the following web site:

Airline Radiation Threat to be Assessed, BBC
Learn about a study to monitor the amount of radiation to which airline passengers and crew are exposed in flight. To learn more about the hole in the ozone layer, visit the following web site:

The Effects of Ozone Depletion, EPA
This page has links to articles that give overviews or broad information, shorter pieces that focus on specific aspects of ozone depletion, international organizations that issue regular updates, and images and animations of ozone levels and ozone depletion. To learn more about the life of British physicist Edward Victor Appleton, visit the following web sites:

Biography of Sir Edward Victor Appleton, Nobel e-Museum
Read a biography of the physicist Sir Edward Victor Appleton.

General Resources

To learn more about each topic, visit the following websites:

Structure of the Sun

Anatomy of the Sun, NASA
Read this in-depth description of the Sun’s structure.

The Earth’s Energy Budget

Climate and Earth’s Energy Budget, NASA
An in-depth article on Earth’s energy budget.

Earth’s Energy Budget, Oklahoma Climatological Survey
Follow along with a two page description of the balance between the amount of energy absorbed into and released out of the Earth’s system.

Harmful Solar Radiation

Health effects of overexposure to the sun, EPA
Learn more about the health risks from ultraviolet radiation.

Sunlight, Ultraviolet Radiation, and the Skin, National Institutes of Health
A report from 1989 that addresses, among other issues, what are the sources of ultraviolet radiation, and is the extent of human exposure changing over time?

Sun and Skin, National Institutes of Health
Article about the dark side of sun exposure.

Ozone Depletion, EPA
Navigate through a web site dedicated to the topic of ozone depletion. In particular, check out the Ozone Science Fact Sheet to review some basic facts.

Sunspots and Solar Flares

Solar Flare Theory, Goddard Space Flight Center - NASA
The purpose of this page is to provide some general information about solar flares, a “feel” for scientific research into the energetic emissions from flares, and a glance into the future of solar flare research.

Animations and Video

To view animations and video related to this topic, visit the following web sites:

Massive Solar Eruption Close-up, NASA
Watch this video that shows a solar flare with a spectacular coronal mass ejection.

Launchpad: Clouds and Earth’s Radiation Budget, NASA
At this website, locate and watch the NASA eClip titled, “Launchpad: Clouds and Earth’s Radiation Budget.” This video examines Earth’s radiation budget.

Section 9: The Lives of Stars

Learning Outcomes

Plan and carry out an investigation to explore the relationship between the brightness of an object (its luminosity) and its magnitude.
Analyze and interpret data relating to the properties of stars.
Obtain information about stellar structure and stellar evolution (the life cycle of stars).

Inquring Further

To learn more about the evolution of the Milky Way galaxy, visit the following web sites:

How did galaxies form?, Science Friday
This discussion includes the formation of galaxies in general as well as the Milky Way.

The Milky Way - Our Galaxy, University of California, San Diego Center for Astrophysics & Space Sciences
This brief article on the origin of our galaxy also includes several images. To learn more about starburst knots in other galaxies, visit the following web sites:

The Birth of Stars, HubbleSite
Page has information on how a star is born.

Witness the Birth of a Star, NASA
Image of star birth.

Stellar Nurseries, NASA
“A new star is born every year in our galaxy.” Learn more about the origin of stars and galaxies. This page also features several Hubble images.

Hubble Sees Starbursts in Virgo, NASA
Learn where stars are forming at such a breakneck rate that the galaxy is eating up its gas supply faster than it can be replenished!

General Resources

To learn more about each topic, visit the following websites:

Classifying Stars

Classifying Stars, Australia Telescope National Facility
Reviews the various variables that help classify stellar objects.

The Lives of Stars

Star Life Cycles, Physics Institute
Watch a video on the life cycle of stars.

New Hubble Image Shows Life Cycle of Stars, CNN
This short article reports on an advancement in understanding star life cycles.

A Star’s Life, HubbleSite
Catch a glimpse of the fascinating life cycle of stars. This movie requires a plug-in to be viewed.

Animations and Video

To view animations and video related to this topic, visit the following web sites:

Launchpad: Life Cycle of a Star, NASA
Take a closer look at the life cycles of stars and learn where stars come from, how they change, and what happens to stars when their lives come to an end.