Supermoon Lunar Eclipse!

Here's your nightly math! Just 5 quick minutes of number fun for kids and parents at home. Read a cool fun fact, followed by math riddles at different levels so everyone can jump in. Your kids will love you for it.

Supermoon Lunar Eclipse!

September 27, 2015

Tonight our Moon will do not one but TWO cool things at once: a supermoon lunar eclipse. In any lunar eclipse, the Moon passes exactly behind Earth on the opposite side from the Sun, putting it right in our shadow. It doesn’t get completely blacked out because some light still scatters around Earth, so instead the Moon looks deep orange. Meanwhile, the Moon isn’t always the same distance from Earth as it travels around us: once a year it’s at its closest point, called perigee. That’s about 31,000 miles closer than the Moon’s farthest point from us, making it look bigger and also brighter. By luck, the moon will be at perigee tonight, so it will become a bigger orange ball than in most eclipses. The Moon will be completely in our shadow starting at 10:11 pm New York time, but will start sliding into darkness around 8:00. So step outside and check it out!

Wee ones: What shape is the Moon?

Little kids: The Moon will spend 2 hours sliding into our shadow, about 1 hour sitting in totality, and then another 2 hours sliding out. About how many hours does the whole eclipse take?  Bonus: If that all starts at 8:11 pm New York time, will the eclipse finish tonight or tomorrow?

Big kids: The next total lunar eclipse won’t happen for another 2 years 4 months. In what year will you get to see that? (We’re in Sept. 2015 right now).  Bonus: Earth is about 8,000 miles wide. About how many Earths closer is the Moon at its closest point than farthest point?

The sky’s the limit – literally: The Moon is full, meaning on the other side of us from the Sun, about every 29 days. If it were exactly 29, how many days from now will we have another full moon on a Sunday?




Wee ones: A circle – or as a 3D shape, a sphere.

Little kids: 5 hours.  Bonus: Tomorrow, since it will end after midnight (in fact after 1 am).

Big kids: In 2018, since the extra months will carry us to January of that year.  Bonus: About 4 Earths.

The sky’s the limit – literally: 203 days. Since a week has 7 days and 29 is 1 more than a multiple of 7 (28), each full moon would land on the next day of the week: the next would be on a Monday, the one after that on a Tuesday, etc. So the 7th full moon after this one would land on a Sunday again, giving us 7 x 29 = 203 days (and it will actually come close to that: April 22, 2016 lands on a Friday).

Happy moongazing everyone!

Print Friendly, PDF & Email

About the Author

Laura Overdeck

Laura Overdeck

Laura Bilodeau Overdeck is founder and president of Bedtime Math Foundation. Her goal is to make math as playful for kids as it was for her when she was a child. Her mom had Laura baking before she could walk, and her dad had her using power tools at a very unsafe age, measuring lengths, widths and angles in the process. Armed with this early love of numbers, Laura went on to get a BA in astrophysics from Princeton University, and an MBA from the Wharton School of Business; she continues to star-gaze today. Laura’s other interests include her three lively children, chocolate, extreme vehicles, and Lego Mindstorms.

More posts from this author