Why does the Moon look bigger at the horizon?
The "Moon illusion," in which the Moon appears larger than normal when close to the horizon, is not the result of magnification by the atmosphere or a change in Earth-Moon distance. Instead, the answer is, as Einstein might say, completely relative.
At most times we see the Moon high in the sky among thousands of stars. We develop our sense of how "big" the Moon ordinarily appears by comparing it with the vast panorama of outer space.
When the Moon is nestled along the horizon, however, we see it surrounded by a foreground of familiar Earth-bound objects -- trees, buildings, or distant landmarks. In comparison with these everyday features, the bright disk of the full Moon appears quite large indeed, and relative to our "normal" sense of the Moon's size, much bigger than we would expect.
» FAQs about StarDate Online
Earth, Moon, and the Sun Links
NASA Eclipse Home Page
Exploring the Moon
Earth Observatory
Earth Science Picture of the Day
Solar Dynamics Observatory
Near-Earth Asteroid Tracking Home Page
SpaceWatch
Lincoln Near Earth Asteroid Research (LINEAR)
Lowell Observatory Near-Earth-Object Search (LONEOS)
Common Holidays in Relation to Equinoxes, Solstices & Cross-Quarter Days
Earth and Moon Viewer
Fireball Data Center
Meteorite Central
NASA Solar Data Analysis Center (SOHO)
North American Meteor Network
The Aurora Page
Virtual Reality Moon Phase Pictures
|
  |
Contact | About | Friends of McDonald | Sign up for Sky Tips
