Earthshine | Moonshine

The Moon is positioned near a new moon phase about every 29 days. At that time, we see only a thin crescent of the illuminated surface. Most of its face toward Earth is in shadow. The view below of the Moon’s orbit is oblique, not from directly overhead. The size of the Moon’s orbit is scaled 50x larger than actual size. A 30 sec animated version is at this link.

Made with Voyager 4.5 |

I enjoy the challenge to see the thinnest crescent sliver of the Moon possible. During the final days of the cycle, as the Moon wanes, I check the southeast sky in the morning before sunrise. The Moon’s crescent appears thinner each day. If my luck is good, the morning sky is clear and seeing is excellent the day before the Moon disappears into the glare of the Sun. Sometimes there is another object nearby such as Venus or Mars. The pairings of two or three objects often make for beautiful photographs. On those occasions, I set the camera on a tripod in front of the house. Hand-held exposures never work.

For the photographers, my settings are often ISO of 160-200, white balance of tungsten or incandescent bulb, f/2.8, shutter speed of one half up to 2 seconds depending on the brightness of the Moon. Manual focus is needed. The camera has a hard time on auto focus. Try a range of settings to find out how your camera performs best.

One of my first attempts was in 2005 when the Moon and Mercury were close. I played around with with photo editing software to add some effects. One of the aspects of these photographs is the visible Earthshine upon the Moon. It faintly shows in the image above. How does Earthshine come about? Why does it happen? Below is a view of the Moon and Earth drawn to scale both in size and distance apart. The view was rendered on my desktop planetarium software. Assume the Sun is far to the left in this view. When the Moon is near new, sunlight travels to the Earth with some small amount reflected back toward the Moon. It is often just enough to illuminate the shadowed side of the Moon if the rest of the sky is darker. Here are more Earthshine photographs. For me, they give a sense of depth to the Moon. They are some of my favorite scenes in the sky. I hope you enjoy them, too. Thanks for joining me.

Moon and Venus | Dec 4, 2005

Old Moon | Jul 13, 2007

Moon Saturn Venus Regulus | Oct 9, 2007

Moon Jupiter Mercury faint below Jupiter | Dec 29, 2008

Moon Venus | Feb 27, 2009

Very Old Moon | Oct 6, 2010

Very Old Moon | Oct 25, 2011

Moon Venus Las Vegas | Evening Nov 26, 2011

Waning Moon | Oct 2, 2013

Waxing Moon | Evening Oct 7, 2013

Waxing Moon Venus | Evening Oct 7, 2013


18 thoughts on “Earthshine | Moonshine

  1. Very good. I particularly appreciate the picture showing the moon and Earth in proper scale, both size and distance. The subjective eye makes us think the moon is much closer to us than it is, but the scale drawing not only shows that it isn’t, it also clarifies the rarity of eclipses.


    • I used a 12″ globe and a baseball to show the kids in school the size comparison. Then, I asked them how to put the baseball for the proper distance. No one ever suggested about 30′ away in the back of the room.


  2. I didn’t scroll down further enough so now I see all of your waning and waxing moon shots. That’s beautiful. Something I’d like to tackle at some point.


  3. These are fantastic images! What a great project. I can tell you are always aware of what the moon is doing on a given night; I am too. So important in feeling anchored to the natural world. The most challenging photos appear to be the ones with the largest crescent lit, all that light drowning out the earthshine. Really beautiful pics, thanks.


    • Thank you. I can tell you appreciate the feeling of anchor. It has always been part of my life. Farm life as a kid helped culture that awareness of the cycles of nature. It runs deep.

      Getting the light just right is an interesting challenge. I am glad we have digital now. No cost worries about taking several bracketing shots to see what works best.

      Thanks for stopping for a visit.


  4. Wonderful photos. The moon truly is fascinating, and there’s something about the crescent moon that seems to me even more beautiful than a full moon. I appreciated the note about the camera settings, too.

    I did have to laugh at what popped to mind as I read your title. Don’t forget starshine! Oh, isn’t that a blast from the past!


    • Thank you. It is always up there like a good friend. It changes day to day. But, you can count on it to be there for you.

      I like the Starshine reference. That goes back to some interesting thoughts. Fun.

      Moonshine made we wonder about saying something clever about the alcoholic drink. But, I decided people could take that trip without my words.


  5. This was such a fun post. I think you’d like my Dad… a year ago he set about finding spheres the appropriate size to each other to demonstrate the solar system to a group he is a member of. We had more fun, seeking out baseballs and ping-pong balls and bee-bees. Then, of course, we had to run around the building finding the right distance to place them.


    • He sounds like a great guy.

      We did that for my science classes. We used a basketball for the sun and various other balls for planets. In the long hall way outside my room, we had someone stand at one end with the basketball. Planet people each stood at an appropriate distance. The Pluto person was just outside the far door about 400 ft away.

      When we came back to the classroom, I asked how far away we would need to place another basketball to represent the nearest star neighbor of the sun. After some guessing of values much too small, I told them it would be about 1000 miles away. They were surprised.

      Tell that to your dad. Thanks for your comments.


  6. When I read your phrase “the thinnest crescent sliver” it occurred to me that by swapping two letters you could talk about a silver sliver of the moon.

    At some point (probably in my 20s) I finally noticed that the shape of the moon fills (waxes) from right to left and then empties (wanes) in the same direction. In antiquity probably every little kid knew that.


    • The letters, numbers, and symbols of language are powerful. Moving or switching them just a bit changes the message a lot.

      Watching the moon and planets and sky gives me a sense of continuity and predictability. It is also powerful stuff.


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