The Last Cuentista STEM: Rotation, Revolution & Tidal Locking

PLANETARY ROTATION,
REVOLUTION & TIDAL
LOCKING

THE LAST CUENTISTA STEM EXTENSION

TEACHERS, check this hack for scoring open-ended questions during a live game.

In Chapter 17 of The Last
Cuentista, as Petra’s shuttle
descends to the surface of Sagan,
she remembers her dad’s
explanation of the planet’s TIDAL
LOCK.

In order to understand tidal
locking, we first need to look at
ROTATIONAL and ORBITAL
PERIODS.

Tidal Locking: Unlocked

A planet’s
ROTATIONAL
PERIOD is the time
it takes to spin
around ONE time.

Getting into the
Spin of Things

Watch this video to learn more and listen for these words: axis, rotation, spin, day & night.

Multiple Select

What’s the connection between day and night and the Earth’s ROTATION? Choose 2.

• It takes one day/night cycle for the Earth to rotate on its axis one time.

• For people who live on the side of the Earth facing the sun, it's day; for people facing away from the sun, it's night.

• The Earth's rotation causes the Sun to move.

• Day and night are caused by the Earth's tidal lock with the sun.

Here’s Earth’s moon. Click here to take it for a spin!

​

Moons Rotate Too!

Open Ended

When you watched the moon spinning on the last
slide, one side probably looked more familiar than the other. Why do you think that is?

Multiple Select

What's your number?

• 1

• 2

• 3

• 4

Spin Class: All Are Welcome!

Rotating is not just an
Earth and moon thing.
Every planet does it.

This video shows the
rotation length for
each planet in our
solar system.

What do you notice?

Open Ended

On the last slide, it doesn’t look like Mercury and Venus are moving. Do you think something’s wrong with the video? Why or why not?

Multiple Select

What's your number?

• 1

• 2

• 3

• 4

Planetary Travel: It’s Revolutionary!

An ORBITAL
PERIOD is the
time it takes a
space object to
travel or REVOLVE
or ORBIT one time
around a bigger
space object
nearby.

Watch this video to learn how it works for Earth.

Match

Match the following.

• rotation

• revolution

• year

• day

spin

orbit

the time it takes a planet to travel around the sun one time

the time it takes for a planet to rotate on its axis one time

• spin

• orbit

• the time it takes a planet to travel around the sun one time

• the time it takes for a planet to rotate on its axis one time

Open Ended

Explain what a year is without using the words month, week, day, hour, minute, or second.

The Space Race: Also Revolutionary

Watch this video
to see the orbital
periods of the
other planets in
our solar system.

Multiple Select

What's your number?

• 1

• 2

• 3

• 4

Orbital Periods: A Look from Above

Watch this video
to see the what
each planet’s
revolution would
look like if we
could speed up
time and look
down at the action
from a distant star.

The video looks like it won't work, but it will!

Getting Orbital on the Moon

Planets orbit a host
star, but a moon
orbits its parent
planet.

Here’s a video
showing the
moon’s orbit
around Earth.

Saving Face in Space

Watch this video to
learn why the same
side of the moon is
always facing Earth.

Multiple Select

Why do we always see the same side of the moon? Choose 3.

• The moon's orbital period is the same as its rotational period.

• The moon is tidally locked with the Earth.

• It takes the moon the same amount of time to spin around once on its axis as it does to orbit the earth one time.

• The moon's surface is constantly illuminated by the sun.

• The moon is tidally locked with the sun.

Dropdown

A moon is usually is tidally locked to​

Select answer

. Sagan is ​

Select answer

​

Select answer

because it takes Sagan the same amount of time to ​

Select answer

on its axis once as it does to ​

Select answer

its sun.

Multiple Choice

What does tidal locking have to do with ocean tides?

• Nothing, it's just called that because ancient astronomers were confused.

• As the moon passes over Earth, its gravity pulls on the ocean in the area beneath it, causing tides.

• As Sagan passes its sun, its gravity pulls on the sun's ocean.

Dropdown

Since Sagan is ​

Select answer

to ​

Select answer

, on the side of the planet ​​ facing the sun , it's always ​

Select answer

, and on the side facing ​ away from the sun, it's always ​

Select answer

.