The Math of Eclipses.

  Tonight is the night of a lunar eclipse also known as a blood moon because the moon turns reddish.  The one tonight is due to be the longest one for this century and it's happening between two solar eclipses.

I wondered what type of math is associated with lunar eclipses  and I found several sites which can give students the opportunity to perform math associated with lunar eclipses.

As stated earlier, the next lunar eclipse is tonight but it cannot be seen in the United States.  Math and You have an exercise where the student can find out when the next visible lunar eclipse happens in their location.  There are also a few questions students need to answer based on the information they have.

This site explains how to calculate the length of a lunar eclipse.  It begins with providing some background information before providing explanations and the data necessary to calculate a variety of factors involved in this type of eclipse.  The nice thing, is the exercise breaks everything down and includes answers at the very end so students can check their work.

NASA even has a page providing the mathematical equations needed to calculate mathematically when lunar eclipses occur from 500 AD on to the future.  Many of these equations are polynomials and could easily be graphed so students can see how the graphs look and how to find the time the eclipse happens.

Since the site also has links to the number and length of each lunar eclipse, students could easily graph the points to see if they can find how often this event occurs.  From what I read, it appears most lunar eclipses occur in January and June or July but they do not usually last as long as the one tonight does.

This site explains what conditions are needed for a lunar eclipse, the view from space, and  the Saros Cycle which ancient people were aware of.  This is important because it shows students that just because the moon and sun get close to each other, they do not always cross paths and the way they cross determines whether you have a solar or lunar eclipse.

Sorry its so short but I took off again to Los Angles and will be home Monday night, quite late.  Unfortunately, I was awake all night, got to the conference so I could set up my area since I'm on the committee.  I am falling asleep as I write this.

Tomorrow and Sunday, I will have my usual warm-ups.  I'm hoping to come up with something really awesome from this conference.  Have a great day.  Let me know what you think, I'd love to hear.