People and animals use plants in many ways. The flowers of plants produce seeds. Water and air are matter because they have weight and take up space. Objects in space follow cycles and patterns over time. Earth has one moon, which revolves around it.
Earth is a planet in our solar system.
Currently we know of nine planets in our solar system. The sun is the center of our solar system. Planets rotate on an axis as they revolve around the sun. Gravity is a force that pulls objects toward the earth. Astronauts need to adapt to living and working in space.