Radar Mapping on Venus activity

This is an activity I'm still rather proud of because I thought of it myself. :) You can see it in its previous iteration here. The idea is to learn about how radar can help astronomers map the terrain of a planet like Venus, where they can't actually see and photograph the surface.

The activity proceeds as follows: First you get a box of some kind and fill it with things to represent mountains, valleys, plains, holes, etc. You want a variety of heights to mimic a varied terrain. Then cover the box with paper so no one can see what's inside. This is like the cloud cover on Venus

Next, take a long wooden skewer and color the bottom end of it a different color every centimeter or so. (I believe last time we used actual cm measurements, but this was a little tricky to figure out—the colors worked better for younger children.) This skewer is like your "radar" which bounces off of objects beneath the "clouds."

Have the children take turns poking the skewer into the paper. For each poke, note the color the skewer goes down to. Whichever children aren't poking can make a map of these colors. If the skewer can only poke down to red, make a red dot in that spot. If it pokes all the way down to blue, make a blue dot. And so on.

The more pokes you make (or the more radar measurements you record), the more accurate the picture of your terrain will be!

Once you've made measurement dots over the majority of your paper, you can translate that into pictoral data and get a topographical picture of your surface. You can see how we did this: on the paper above, we have a big area of turquoise dots in the left corner, a long area of pink dots along the right side, and so forth. Once those areas were filled in with color, the result was the paper below. You can read this map by remembering that the colors move from warm (high) to cool (low)—dark blue is a low valley; light pink is a high mountain.

We tore off the paper over the box to see how accurate our map was compared to the actual terrain. Pretty good! We accurately mapped the valley on the left side, the long parallel mountain ranges, the deep sinkhole, and even the long sloping hill (the slide).

The children had so much fun doing this that they wanted to keep doing it on their own. They loved hiding objects under the paper and then poking through to see what they could discern about them!

When we talked about Venus, we also discussed how clouds form, and how air pressure relates to cloud formation. 

We followed the instructions for this "cloud in a jar" activity here. This little demonstration shows how as you push down on the balloon (increasing the air pressure in the jar) and then release that pressure, a "cloud" instantly forms in the jar.