Eclipses
You may have heard of an eclipse on your local news broadcast. They take place so few times a year that they often are prominent topics on the news when one is about to take place. Throughout history, humans have wrongly associated eclipses with cataclysmic events. While you may have heard of solar eclipses and lunar eclipses seen on Earth, other astronomical bodies, like other planets and their moons experience eclipses.
An eclipse occurs when an astronomical object moves in front of another. Look at the animation shown here to the right. The white disk moves in front of the teal disk in a constant speed. Once the white disk begins to cover part of the teal one, an eclipse takes place.
In terms of astronomy, eclipses occur when sunlight is blocked. In a solar eclipse, the moon casts a shadow upon the Earth. In a lunar eclipse, the Earth casts a shadow on the moon. Eclipses can be total or partial eclipses. How can the moon or Earth block sunlight if they are significantly smaller than the sun? Click on each of the tabs in this interactivity to explore the types of eclipses and how they occur.
Download a printable version of the interactivity.
An image of a lunar eclipse from November 2003
To see an animated version of how a lunar eclipse occurs, view the video Lunar Eclipse Essentials from eMediaVA℠. Since these events occur relatively frequently, you may have seen one or be able to see one. As you view the video, take note of the following:
- How many times does a lunar eclipse occur during a year?
- What is the penumbra?
- What is the umbra?
- What color does the moon turn during a lunar eclipse?
Now, view an animated version of how a solar eclipse occurs by viewing the video Total Solar Eclipse Animation from eMediaVA℠. While viewing the video, make note of the factors that have to be in place for a solar eclipse to occur. Use the questions below to help guide you:
- What is the path of totality?
- What is the corona, and how does the moon relate to it during a solar eclipse?
- How often does a total solar eclipse occur?
Eclipses Review
Now that you have learned about solar and lunar eclipses, check your knowledge in this non-graded activity. Choose the option (or options) that best answers the question. Then, click SUBMIT to check your response. Click the interactivity thumbnail, and then click NEXT to begin.