Sky to Space
Astronomy Beyond the Basics with Comparisons, Ratios and Proportions

Projects - the Sun, Moon, eclipses, ideas for adult learners and your homeschool curriculum

More on topics from the book!


Here's more to explore in connection with topics and projects from the book!


Chapter 1: Comparing

Hop over to the graph paper page on this site for quick and easy printable one-centimeter squares!

Look up the sizes and distances of planets and moons at National Space Science Data Center or this NASA Solar System page

Asteroid Apophis was the subject of a good article by Phil Plait, written in 2016 when his Bad Astronomy blog was at Slate magazine.

Chapter 2: Seeing

To get an idea how large the International Space Station appears in our sky, go to Astronomy Picture of the Day, find the search box and type in "ISS Sun," then "ISS Moon," and see what amazing pictures you get.

About Phobos passing in front of the Sun as seen from Mars: did you do your own figuring about how big it would appear? To compare your prediction to some photos of the real thing, go to the NASA Mars Exploration Program page, click on "Multimedia," then type "Phobos eclipse" into the search box and scroll through what you get!

Chapter 3: Proportions

One of the very first photographs of the Moon, taken in 1849, shows how far the Moon moves in the sky in two minutes due to Earth's rotation. Actually it's a set of several exposures lasting different amounts of time. Evidently the camera was sitting still on a tripod, so the Moon's image is smeared by Earth's rotation. Search for the page of "Daguerrotypes at Harvard," then scroll through "Collection Highlights." Or try this direct link. Notice the handwritten notes next to the photo, giving the exposure time for each image of the Moon.

Chapter 4: An Artist Who Took Us Into Space

Chesley Bonestell's dramatic paintings of Saturn as seen from its moons became famous when they were printed in Life magazine in 1944. You can view this issue online. In the book I recommend you go to and type in "Life magazine May 29, 1944." From there, for some reason, you have to scroll through several screens of Life magazines to find this particular issue. Hint: the cover has a photo of General "Tooey" Spatz. Or try this link. Once you find the magazine, look inside for the "Solar System" article.

On the commercial site io9, Ron Miller has provided fine illustrated articles about early space artists Lucien Rudaux and Scriven Bolton.

If you like space art, be sure to look at the International Association of Astronomical Artists (IAAA). Find the link to "Gallery of IAAA Art."

Chapter 5: Our Moon

On page 69, the book challenges you to predict what phase of Earth was seen from the Moon when the Apollo 14 mission landed there on February 5, 1971. Your first step might be to find out the phase of the Moon as seen in Earth's sky on that day. Use your favorite astronomy app. Or go to the U.S. Naval Observatory Astronomical Applications Department -> Data Services -> Synthetic Views of Selected Solar System Bodies -> Apparent Disk of Solar System Object. Select "Moon," then plug in 1971 February 5. You'll see a picture of the Moon's phase. Next, use what you know about the relationship between Earth and Moon phases to predict what phase of Earth was seen from the Moon that same day. Finally, look for a real photo of Earth taken from the Moon by the Apollo 14 crew. Try the new NASA images website, and search for "Apollo 14 Earth" for a photo of Earth in the sky above the Lunar Module. See if you were right  about the phase!

Chapter 6: Moon FAQ

A 2015 article in Sky and Telescope gives a good introduction to the moon illusion, which makes the moon appear extra-large when it is low in the sky.

For beautiful photos of the Sun and Moon refracted and reddened, visit Earth Science Picture of the Day, then type "sunrise," "sunset," "moonrise" or "moonset" into the search box. For example, try this moonset or this sunrise.

Chapter 7: At Home in the Sky

There is a famous old-fashioned picture showing a man poking his head through the sky. It is supposed to illustrate how people once thought the sky was a dome placed on top of a flat Earth. To see various versions of this picture, go to Wikimedia Commons and search for "Flammarion woodcut."

Chapter 8: Moon and Month

Wonderful and accurate animations of the Moon's motion are yours to enjoy at the NASA Goddard Space Flight Center Scientific Visualization Studio. Check out the popular "Moon Phase and Libration" movie for the current year, then look at some of the many other great videos and still images illustrating the Moon, Earth, space flight and many other topics!

Chapter 9: Eclipses

Hop over to the eclipses section of this website for links to great stuff!

Who was the very first person to realize that there would be solar eclipses in 2017 and 2024? It may have been Theodor von Oppolzer, a German astronomer who calculated the dates and paths of thousands of eclipses back in the 1880s. (There were no computers or calculators at that time. He had to do all the math with a pencil.) He put his calculations into a book with the German title Canon der Finsternisse, which means Table of Eclipses. You can view this old book online and see what is probably the very first map of the paths of totality for these eclipses that we are so excited about today. Go to, look for the "search" box, and type in "Oppolzer eclipses." (Be sure you are typing into the search box, not the Wayback Machine...that's something different.) Click on the title Canon der Finsternisse when you see it. An image of the book will appear. Find and click the icon to go to full-screen view, then figure out the controls for turning pages and go almost to the end of the book, to pages 734 and 735. Look carefully at the map for the tracks for "2017 VIII 21" and "2024 IV 8." To get you started, here is a direct link to the book. You can take it from there!

Chapter 10: Beyond

We now know about so many planets orbiting other stars that you need some kind of search service to find out about any particular one. A news service highlighting the most interesting exoplanets is helpful too. NASA's new Exoplanet Exploration page provides easy links. Find the link to the "New Worlds Atlas" to look up information on a particular exoplanet. 

Here is the European Southern Observatory's science release about the TRAPPIST-1 exoplanet system, "Ultracool Dwarf and the Seven Planets." While you're there, check out the many beautiful pictures taken by ESO telescopes.