Rocket spins slowly in the middle of the room with a lamp in the corner. "Lamp in front of me: day," he says. "Lamp behind me: night!"
Raven laughs and walks him in a big circle around the lamp while he keeps spinning.
"Now you are spinning and orbiting," she says. "What do you notice?"
Nova follows them, projecting a calendar. "Spin once for a day," she says. "Circle once for a year."
Rocket wobbles to a stop. "Being a planet is dizzy work," he says.
Earth rotates, or spins, once about every 24 hours. NASA measures it as 23.9 hours.
As Earth spins, your side faces the Sun for day and turns away for night.
Earth also orbits the Sun. One full trip takes about 365 days, which is one year.
The spinning makes the Sun seem to move across our sky. That is why shadows change during the day.
Earth's axis is tilted. This tilt causes the seasons.
In June, the Northern Hemisphere gets the Sun's most direct rays. It is summer there.
The summer solstice has the most hours of sunlight in the year. The winter solstice has the fewest.
Earth's distance from the Sun is not what causes the seasons.
| Statement | True or false? |
|---|---|
| Earth rotates once about every 24 hours. | ? |
| Earth takes about one month to orbit the Sun. | ? |
| The seasons are caused by Earth's tilt. | ? |
| The summer solstice has the fewest hours of sunlight. | ? |
Earth makes two big motions at once.
It spins once about every day, which gives day and night.
It circles the Sun once a year. Its tilt during that trip gives the seasons.
You modeled the whole Earth with your own body. Tomorrow we will see how the night sky changes with the seasons.