Science
by Kim Hughes
October 04, 2007
We are beginning a new unit on Earth Science. The Earth is very old. Fossils are preserved pieces of plants and animals that lived long ago. The first plants and animals lived in the oceans. Some early plants and animals were very different from today's plants and animals. Long ago, Earth looked different than it does today. Water, wind, volcanoes, earthquakes, and landslides have changed the land. Earth is shaped like a ball. It takes one year for Earth to travel around the sun. The moon moves around Earth and is visible when the sun shines on it. The sun warms Earth and the air around it. It helps plants make their own food. Stars are balls of burning gasses. Stars are suns. (even though we see them at night!)
Chapter 4 is the first one the we will read in this unit. It is about "How Earth Changes". Earth's appearance has changed over the years. Fossils provide people with a look into what Earth was like millions of years ago. Some fossils are shapes imprinted in rock and some are bones or shells. The first plants grew in oceans and did not resemble today's plants. Early plants had no roots or leaves. They did, however, need air, water, and sunlight to make their own food. Animals also changed over the years. The first animals were insects, spiders, and frog-like animals. Much later came dinosaurs and mammals. Water and wind also changed the surface of Earth through erosion and through the movement of sand an soil from place to place. These changes are slow. Volcanic eruptions, earthquakes, and landslides change Earth quickly.
