Rocket and Raven stand on a rocky beach as a storm rolls in. Wind whips the waves. Gulls ride the gusts.
"So much is happening at once," Rocket shouts over the wind. "How do scientists even study all this?"
Raven points at the cliff, the sea, the clouds and the birds. "What do you notice? Four kinds of things," she says.
Nova projects four colored circles in the air: brown, blue, white and green. "Earth has four big systems," she says. "Let's sort them."
Rocket grins. "Rock, water, air and life," he says. "Let's build the map."
| System | What it includes | Beach example |
|---|---|---|
| Geosphere | Solid and molten rock, soil and sediments | The cliff and the sand |
| Hydrosphere | Water and ice | The ocean waves |
| Atmosphere | Air | The wind and storm clouds |
| Biosphere | Living things, including humans | The gulls, seaweed and people |
Scientists call each of these a system. Each one has many parts.
The four systems are always interacting. Something in one system changes something in another.
To sort something into a system, ask what it is made of.
Rock, soil and sand go in the geosphere. Water and ice go in the hydrosphere.
Air goes in the atmosphere. Anything alive goes in the biosphere.
| Thing | Is it part of the biosphere? |
|---|---|
| Seaweed | ? |
| A rocky cliff | ? |
| People on the beach | ? |
| Ice on a pond | ? |
Great sorting. Tomorrow we will see how the systems change each other.