APOD
Astronomy Picture of the Day
Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.
Blue Moon Tree
Explanation: Does an alignment like this occur only once in a blue moon? No, although it was during a blue moon that this single-shot image was taken. During a full moon that happened to be the second of the month -- the situation that defines a blue moon -- the photographer created the juxtaposition in late January by quickly moving around to find just the right spot to get the background Moon superposed behind the arc of a foreground tree . Unfortunately, in this case, there seemed no other way than getting bogged down in mud and resting the camera on a barbed-wire fence. The arc in the oak tree was previously created by hungry cows in Knight's Ferry , California , USA . Quirky Moon-tree juxtaposition s like this can be created during any full moon though, given enough planning and time. Another opportunity will arise this weekend, coincidently during another blue moon . Then, the second blue moon in 2018 will occur, meaning that for the second month this year, two full moons will appear during a single month (moon-th). Double blue-moon years are relatively rare , with the last occurring in 1999, and the next in 2037.
| Date | March 28, 2018 |
|---|---|
| Credit | Image Credit & Copyright: Eric Houck |
| Authors & editors: | Robert Nemiroff (MTU) & Jerry Bonnell (UMCP) |
| A service of: |
ASD at NASA / GSFC, NASA Science Activation & Michigan Tech. U. |



