80 Miles to Play-Doh Part I: When Without, Improvise!

Last week, I had the privilege of traveling to Chinle, AZ to participate in a series of educational activities related to the Moon and LRO. Traveling from the DC area, I flew to Albuquerque on Sunday in preparation for a scouting trip to Meteor and Sunset Craters on Monday. Tuesday evening, my colleagues and I were to lead an evening's worth of activities that included viewing the Moon through a telescope and discussing how scientists use Earth analogs to understand the processes that occur elsewhere in the solar system.

Monday evening, one of my fellow NASA educators mentioned that it would be a good idea to prep some hands-on activities for the students for the evening's events. After all, if we're going to be discussing volcanoes and impact craters, why not have the students investigate how they're made in the first place? We all agreed that it was a good idea and decided on our drive back to Chinle from Flagstaff that we would go to the grocery store in the morning to pick up supplies. For those of you whom have never made volcanoes in the classroom, you need the following supplies:

baking soda
vinegar
paper plates
paper cups
paper towels
clear straws
play-doh

Now, most of the items on the above list can be readily found at any grocery store - after all, they're all pretty common in the baking isle. On the other hand, play-doh isn't an item typically found in the grocery store. If you happen to live in an urban area, any pharmacy or big-box store would most likely have play-doh. However, if you're in Chinle, AZ, the closest big-box store or pharmacy is over 80 miles away (one-way), and in another state! So here's where our plan got interesting. There are plenty of home-made play-doh recipes out there, but most of them call for you to cook your dough (or at least to include boiling water). What's an educator to do?

My colleagues and I wandered through the small grocery store, searching desperately on our slow cell phone internet connections for a recipe to make play-doh that doesn't involve cooking. The non-cook play-doh options weren't viable for us, so we were stuck. "Wait a minute," I exclaimed, "we can use the coffee pot to heat the water up!"

So, there we were. It was 3 pm, 4 hours before the event was scheduled to start. Pouring flour, salt, cream of tartar, kool-aid, oil, and water heated in the coffee pot into the sink in the hotel bathroom. Yep, I said the sink! Turns out, a hotel sink is a perfect bowl to make home-made play-doh, and it's easy clean up. I couldn't help but laugh at our situation. If you ever asked me if I ever thought my job would have me on a Navajo reservation, 80 miles from the nearest Wal-mart, mixing play-doh in a hotel sink, I would have answered with the requisite "are you crazy?" We made cherry, orange, mango, and grape colored/flavored play-doh. The grape play-doh looked like a warm, giant ball of chewed bubblicious gum. :-P

The event turned out really well. We had about 60 people, made up of families with kids of all ages show up for our event. Everyone had a great time making volcanoes out of our home-made play-doh and learning how impact craters are made. The clouds even (mostly) cooperated with us, enabling everyone to get a close up sight of the Moon through the telescope!

View Tonight's Total Lunar Eclipse - The Last One Until 2010!

Tonight, February 20, 2008, will be your last opportunity to view a total lunar eclipse until December 2010. A lunar eclipse occurs when the Earth lines up directly between the Sun and Moon such that the Earth's shadow completely covers the Moon's surface. Tonight's eclipse will last for about 3.5 hours, 50 minutes of which the Moon will be in totality. During the eclipse the Moon will change color from gray to red. This is due to the glow cast on the Moon from indirect sunlight passing through Earth's atmosphere. The Moon's color during an eclipse varies based on the amounts of dust and clouds in the Earth's atmosphere. The more dust in the Earth's atmosphere, the more red the Moon will appear. The United States will be able to view the majority of the eclipse. Click on the above map above to determine your best viewing times.

To learn more about tonight's eclipse, see the NASA Eclipse Home Page and this NASA feature story. To learn more about eclipse terminology, see the Educator's Guide to Eclipses. Click here for a classroom activity on creating two scale models of the Earth-Moon system that can be used to demonstrate lunar phases and eclipses. Click here for an eclipse viewing activity for students.

Happy viewing!!!

The Other Side of the Moon: Synchronous Rotation lesson

Have you ever wondered why we only see one side of the Moon? Well, the reason why we never get a shot of the far side of the moon is because the Moon is in what we call a "synchronous rotation" with the Earth. That is, it takes the Moon the same amount of time to rotate on its axis (or one lunar day) as it does to make one orbit around the Earth. The lesson highlighted in this entry was written by the Cassini team to explain how moons move in synchronous orbits.

Grades 5-8
Time required: 1 hour

Materials
Desk chair that rotates
Rubber, styrofoam, or tennis ball
Pencil or long dowel
Marking pen
Desk lamp or overhead projector
Optional: strong adhesive tape

Procedure:

Stick the pencil or dowel (for use as a handle) through the ball along a diameter; this simulates the Moon. With the marking pen, write a large letter or number every 90 degrees around the circumference of the ball. The handle will either be held at arm’s length by a student sitting in the chair or it can be taped to the armrest of the chair. Place the chair (Earth) a few feet away from the desk lamp or over- head projector (the Sun). The students can stay in their seats for this demonstration or they can gather in a circle around the Sun–Earth–Moon system. Ask the students if the Moon rotates. Most will say no, since they have seen the same face of the Moon whenever they have looked up in the sky at it. Choose a student to sit in the chair and watch the ball-Moon with numbers/letters on its quadrants. Slowly turn the student in the chair and ask that student if the view of the Moon is changing. The answer will be no; the hemisphere the student observes is always the same. In contrast, the other students will see the different quadrants appear as the chair makes one full rotation. This proves that the Moon rotates, even though it presents the same face to Earth (the student in the chair).


For the full lesson, please see lesson "What is Synchronous Rotation?" on the Saturn Educator web page.