Moon - Sun = Solar Eclipse

Hopefully you have time to appreciate the total solar eclipse tomorrow. While we will only get to appreciate 60% of the eclipse in San Diego, the phenomenon is pretty cool! This unique and spectacular event is both an amazing coincidence and yet highly predictable, due to math!

Have you ever stopped to wonder how a solar eclipse is even possible?  It’s a basic math problem. For those at the right place at the right time, the moon will 100% block the core of the sun, allowing spectators to see the outer surface of the Sun, the corona. We all know the moon is a fairly “small” celestial object compared to the Sun, yet the distance between them gives the illusion of similar size.  When they align, the moon casts a shadow on the earth resulting in darkness.

The image to the right shows the Path of Totality based on how much of the sun is blocked by the moon (photo cred here). We will see the outermost image from Southern California. The amazing astronomers and mathematicians are able to calculate the following due to geometry, scaling, ratios, and time:

• “Greatest” eclipse for today:  For a full 2 minutes and 40.1 seconds more surface area of the sun will be covered that at any other time and this will happen in Hopkinsville, Kentucky
• Longest window of the eclipse will last: Makanda, Illinois will have the longest length of time for their eclipse topping off at 2 minutes and 40.2 seconds!
• Next Lunar Eclipse:  January 31, 2018
• Next Solar Eclipse: April 8, 2024

Here are some awesome weblinks to make the most out of the experience!

• To watch the eclipse live from the safety of your computer:  https://www.nasa.gov/eclipselive-info
• To brave it outside, please follow these tips for eye protection:  https://www.nasa.gov/content/eye-safety-during-a-total-solar-eclipse
• To learn more about eclipses:  https://www.nasa.gov/eclipse
• To build your own pinhole camera to watch through:  https://www.jpl.nasa.gov/edu/learn/project/how-to-make-a-pinhole-camera/