Scientists have discovered that stars are not equal. They vary in size and color. Variable stars change in brightness over the course of hours, days, weeks, or years. Reading Essentials in Science.
People once believed that Earth was the center of the solar system. Scientists finally learned that Earth is one of at least eight planets in our solar system and that they all travel around the sun. Astronomers now know that our solar system is almost 5 billion years old and is part of at least 100 billion galaxies in the universe. Earth is the only planet known to have life and water. Scientists continue to discover new planet-like objects, called dwarf planets, all the time!
Long ago, astronomers believed that the Earth was the center of the universe. But now we know that it is only a tiny part of the universe and that our solar system is just a tiny part of our galaxy. In 1957, space travel began. Work done in space has helped us in the areas of medicine, computer science, and the environment. The International Space Station, a lab floating in space, is where astronauts do experiments that help us on Earth. The next manned trip to the moon is planned for 2018.
Gravity keeps people grounded and prevents them from floating away into space! Young readers will learn how and why gravity works and discover how to measure it on Earth. Blastoff! Series
A basic introduction to the planet Mercury, its size, composition, and place within our solar system.
A basic introduction to the planet Jupiter, its size, composition, and place within our solar system.
A basic introduction to planet Earth, its size, composition, and place within our solar system.