Daytime Moon

StarDate: June 29, 2009

You are missing some Flash content that should appear here! Perhaps your browser cannot display it, or maybe it did not initialize correctly.

audio/mpeg icon

By far the brightest object in the night sky is the closest heavenly body to Earth: the Moon. But contrary to popular belief, night isn't the only time to see the Moon. It's visible during the day, too -- and the next few afternoons are a good time to look for it.

Because the Sun is so brilliant, it fills the sky with light. That glare washes out all the other stars, so you can't see them after sunrise. But the Moon is different. It's just a quarter million miles away, and it's so bright that not even the full glare of daylight can vanquish it.

To see for yourself, look toward the west the next few afternoons. Tomorrow, the Moon rises around mid afternoon, and is low in the south by the time the Sun sets. The Moon will rise a little later each day after that. At the same time, it'll get a little fuller, so it'll shine brighter. It'll be full on July 7th, when it rises at sunset and shines all night long.

The Moon is visible in daylight because of the Sun itself. When you see the Moon, you're really seeing sunlight reflected off the lunar surface. So if the Sun went dark, so would the Moon. All you'd see would be a tiny black disk blocking out the light of the stars behind it.

So this simple observation should dispel a common astronomical myth: that the Moon is visible only at night. In fact, the Moon is quite easy to see in a sky-blue sky -- using nothing more than your own two eyes.

Script by Ken Croswell

For more skywatching tips, astronomy news, and much more, read StarDate magazine.

The one constant in the Universe: StarDate magazine


©2014 The University of Texas McDonald Observatory