Posted by BC on June 17th, 2008
As astronomers, we are frequently asked why the Moon looks very large when it is on the horizon. My standard answer is that we have a reference to use along the horizon, so the Moon looks larger than when it is higher in the sky with nothing to compare it to. If a person stretches out his/her arm full length, and puts up a pinky finger, the end of the finger should cover the Moon no matter where it is in the sky. Some people use a dime to cover the sight of the Moon.
The apparent size difference of the Moon, depending on where it is sitting, is called the Moon Illusion, but during the Summer Solstice we have a special Solstice Moon Illusion. It is discussed fully in an article by NASA. Since Summer Solstice (Northern Hemisphere) is 20 June 2008, on June 18 we will be able to see the Solstice Moon Illusion.
3 people have commented
June 19th, 2008 @ 6:07 pm
Skies clouded where I live. Did any of you see the Solstice Moon Illusion?
June 20th, 2008 @ 1:54 am
It rose bright and beautiful
in the warm and muggy clear Texas night.
June 20th, 2008 @ 5:37 pm
Did you happen to take any photos of the Solstice Moon rising? I would be interested in seeing one or two.