Homepage

What is an eclipse?

An eclipse occurs when the Sun, Earth, and Moon are aligned in a straight line.

If the Moon is in the shadow of the Earth, we call that a lunar eclipse. The image to the left shows a time lapse of the lunar eclipse on May 16, 2022 from the catwalk of the Harlan J. Smith Telescope at McDonald Observatory. You can see the Moon gets dimmer and redder during the eclipse.

If the Earth is in the shadow of the Moon, we call that a solar eclipse. To learn more about the types of solar eclipses, have a look at this NASA page.

Eye Safety

Proper eye safety is EXTREMELY important during an eclipse.

Please visit this page from the American Astronomical Society to learn more about how to safely view eclipses.

If you are ordering glasses or viewers for yourself, make sure you order from a reputable dealer! Please use a dealer from this list. Angelo State University has ordered from Rainbow Symphony and I highly recommend them.

Annular Solar Eclipse on October 14, 2023

• Interactive Google Map by Xavier M. Jubier
• Eclipse circumstances in San Angelo, TX (click on the yellow "Calculate Eclipse Circumstances" button near the top)
• What kind of weather can we expect? (and here is more detailed information on the weather, special thanks and credit to NWS and Mike Castillo!)

Total Solar Eclipse on April 8, 2024

• Interactive Google Map by Xavier M. Jubier
Eclipse circumstances in San Angelo, TX (click on the yellow "Calculate Eclipse Circumstances" button near the top)

Educational Materials

Here is a (non-exhaustive) list of some classroom or at-home activities related to eclipses that I think are good.

• Guide for Educators from NSTA
  • Basic information about the Oct 14, 2023 and Apr 8, 2024 eclipses.
  • Information about eye safety.
  • Classroom activities.
• Interactive Eclipse Explorer
  • Click on the hamburger menu in the upper left to see different simulations and options.
• Yardstick Eclipse Visualization
  • This is a great way to visualize the alignment required and small path of a solar eclipse.
• NSTA Eclipse Resources Page
• Eclipse Resources from Rice University
• Sun Tracker Activity
• Viewing Sunspots with binoculars
  • It can be dangerous to use an unfiltered telescope or pair of binoculars to view the Sun! Viewing with a good solar filter is much safer.
• A solar viewer with lenses (by Terry Richardson)
  • Any time you use lenses to focus sunlight it can potentially be dangerous, PLEASE be careful and safe.
• DIY Sun Science App
• Lunar Phase Simulator

More Information

Looking for more information?

• Eclipse Page of the American Astronomical Society
• NASA's Eclipse Webpage
• Information for Specific Groups (local governments, educators, reporters, citizen scientists, etc)