# Finding Evidence of the Revolution of the Earth Around the Sun

Find evidence of the revolution of the Earth around the Sun in everyday things. First, study the length and direction of shadows. Second, analyze patterns of day and night. Finally, look up in the night sky. Some constellations appear only in certain seasons. All of this provides evidence of Earth’s orbit.

## Mr. Grow Prepares to Teach Earth’s Orbit

Our favorite fifth grade teacher gazed thoughtfully at the Next Generation Science Standards. “Oh boy,” Mr. Grow said to his mentor. This standard is a doozy.” He read NGSS 5-ESS1-2 aloud

Represent data in graphical displays to reveal patterns of daily changes in length and direction of shadows, day and night, and the seasonal appearance of some stars in the night sky.

“Hmm,” Ms. Sneed responded, “let’s deconstruct the standard. That way, you’ll know what to do.”

### Intent of the Standard

“Okay. First, it says kids should represent data in graphical displays. I guess that’s just a fancy term for putting numbers in tables or graphs. Easy enough – and another great opportunity to integrate math and science. Then it mentions daily patterns of shadows.”

“Do you think they mean daily or yearly patterns?” Ms. Sneed asked.

“I’m actually not sure. Let’s look at the remainder of the standard. Next, they talk about patterns of day and night. And finally, they add seasonal appearance of stars in the night sky.”

## Shadows Illustrate Rotation and Revolution of the Earth

“Wow,” said Ms. Sneed. “I wish they’d just come right out and say it. Do you think they’re talking about rotation or revolution of the Earth?”

“Since it doesn’t say, I think I’d like to address both.”

Ms. Sneed nodded thoughtfully.

### Length and Direction of Shadows During the Day – Earth’s Rotation

“For rotation,” Mr. Grow continued, “I think I’ll do the shadows activity with sidewalk chalk.”

Ms. Sneed smiled. “Yes, that’s a fun one.”

“To make things run smoothly, I’ll pair them up. Each student in a pair will draw the other’s shadow. Then they’ll record their observations.”

“How often will you have them draw?” Ms. Sneed asked.

“Well, if they go out every 90 minutes, it should work well with my schedule. That means they’d draw at 9:00, 10:30, 12:00, and 1:30.”

“Since you go past noon, they’ll see the shadow get shorter and then longer. Furthermore, it will rotate around their feet. Perfect!”

### Length and Direction of Shadow’s Over the Year – Earth’s Orbit

“However,” said Mr. Grow, “I’d like them to see evidence of the revolution of the Earth as well.”

“Then I suggest using the shadow of our school building,” his mentor said. “Since we are in the northern hemisphere, they will observe that the shadow gets longer every month until the end of December. Then it gets shorter.”

“Of course, we’ll have discuss the Earth’s tilt too. As a matter of fact, I think I’ll extend instruction to the seasons and climate zones.”

## Daylight Hours Change During Revolution of the Earth

“That ties in with the part about day and night,” Ms. Sneed said.

Both teachers sat in silence for a few moments, pondering the concepts surrounding revolution of the Earth.

“If we begin the year with shadows, kids can record them every month through December. Then I’d like to have kids compare sunrise and sunset in two locations – one in the northern hemisphere and one in the southern.”

“As a bonus, they can calculate elapsed time,” Ms. Sneed added.

Mr. Grow chuckled. “That will provide much-needed practice for a tricky math concept. Furthermore, recording daylight hours through the December solstice will really give them something to think about!”

## Zodiac Constellations Provide Evidence of the Revolution of Earth

Ms. Sneed sighed. “What about the part with the seasonal stars?”

Mr. Grow tapped his pencil on the desk. “Hmm. Maybe zodiac constellations. Earth’s orbit around the Sun causes us to see different stars on the ecliptic each season.”

As usual, Ms. Sneed opened her laptop and began clicking away. “Here!” she exclaimed. “Kids can make a cylindrical model of the zodiac belt. Then they will record which constellations are seen each season. Moreover, they manipulate the Earth and Sun to solidify the concept.”

Mr. Grow pulled out his planner. “Now it’s time to pencil all this in. Let’s see. In August, the kids will draw their shadows over the course of one day. After that, they’ll record changes in the school building’s shadow for five months. Then in December, we’ll analyze daylight hours.”

“January or February is a great time of year for stargazing,” Ms. Sneed said. “Maybe you could continue with the zodiac constellations after winter break.”

“Good idea.” Mr. Grow continued writing for a few minutes. Then he looked up and grinned. “Oh yeah. This series of space science activities will really get the kids thinking about rotation and revolution of the Earth!”

## Enjoy Teaching Revolution of the Earth

When kids are engaged and learning, I really enjoy teaching. In my many years of teaching, I’ve found joy in unfolding complex space science concepts (like revolution of the Earth) little by little over many months. Try it. You’ll like it!