Here Navigation There Navigation Everywhere Navigation

Topics: light that does not pass.

You are relaxing with a book on a nice sunny day when a friend leans over your shoulder and the page goes dark. "Hey, you're blocking my light!" It is a familiar

experience. Any time an object blocks the light from another source, it forms a shadow.

Learn more about Shadows.

large shadows triptych
People in Shadow.
When a light source is blocked, a shadow results. Here we see the familiar shadows from people on a beach whose bodies are blocking the light of the Sun from reaching the sand behind them.
Image: Stock Photography
Lunar Eclipse.
The light we see from the Moon is produced by reflected light from the Sun. During a "lunar eclipse," the Earth blocks the light from the Sun and casts a shadow over the Moon. Some light is bent by the Earth's atmosphere and does reach the lunar disk, producing the (often-seen) faint red glow.
Image: John Chumack/Science Photo Library
A Moon of Jupiter.
Shadows occur on other planets as well. In this image, sunlight shining onto Jupiter is blocked by one of its moons as it passes over the face of the planet. A similar type of event takes place on Earth during a solar eclipse, when the Moon blocks the Sun's light and casts a shadow onto some portions of the Earth.
Image: NASA/Cassini

Where do shadows occur?

Here, there and everywhere that an object blocks the passage of light.

Related Resources

"Here, There, & Everywhere" (HTE) is supported by the National Aeronautics and Space Administration under grant NNX11AH28G issued through the Science Mission Directorate.

HTE was developed by the Chandra X-ray Center, at the Smithsonian Astrophysical Observatory, in Cambridge, MA.

Email: cxcpub@cfa.harvard.edu   |   Phone: 617.496.7941
Follow us: #HTEScience on Twitter