Introduction Heavenly Bodies:
Solar system is Sun and everything that travels around it. Solar system is elliptical in shape. That means it is shaped like an egg. The Sun is in the center of the solar system. Solar system is always in motion. Eight known planets and their moons, along with comets, asteroids, and other space objects orbit the Sun.
Sun is just one of about 100 000 million stars that make up our Milky Way galaxy. The Milky Way is one of many such star systems, each of which is called a galaxy. The Universe consists of about 100 000 million galaxies, each containing their own stars, planets and clouds of gas and dust, out of which stars and planets are born. The Universe contains billions of galaxies, each containing millions or billions of stars. The space between the stars and galaxies is largely empty.
The movement of the Earth in an almost perfect circle around the Sun takes 365.26 days. Together, these days produce our year on Earth.
The Solar System:
The Sun, Eight planets, Five dwarf planets, Many moons orbiting the planets and dwarf planets, Thousands of small Solar ,System bodies and Interplanetary dust.
The Sun’s heat and light provide the energy for life to exist on Earth. The Sun is a giant ball of extremely hot hydrogen and helium gases, nearly 150 millio kilometres away. It is gigantic compared to the Earth.
Although all the planets of our Solar System were formed at the same time and from the same cloud of gas and dust, there are great differences between them. The four inner terrestrial (Earth-like) planets are Mercury, Venus, Earth and Mars, and are mainly made of rock and metal.
Earth is the largest of the rocky (terrestrial = Earth-like) planets. The word “earth” is Old English and comes from German. As far as we know, the Earth is unique in the Solar System for two reasons: it has liquid water on its surface and it supports life. Earth is humanity’s home planet. Most of its surface (over 70%) is covered with oceans, with the rest featuring a wide variety of land forms, from mountains and valleys to plains and beaches. Earth has a thick atmosphere, which is mostly nitrogen (78%) and oxygen (21%), with other gases such as argon, carbon dioxide, and water present in small amounts. The region on and near the surface of Earth (both above and below ground) is filled with life.
The Moon is the Earth’s satellite. It is a rocky body orbiting our planet at a mean distance of 384 000 kilometres. The shape that we see depends on where the Moon is in its orbit around the Earth. The Moon seems to move across the sky during the night. It rises in the east. It sets in the west. The Moon seems to move because Earth rotates.
Rotation of the Earth:
The Earth orbits around the Sun. It takes one year to go around the Sun one complete time. The Earth also rotates, or spins, on its axis. It takes one day to spin around itself one complete time. The Earth’s axis is not straight up and down, but tilted at an angle of 23.5 degrees. The rotation is what causes the change from day to night. This tilt is responsible for having seasons. If the Earth were not tilted, we would have the same season all year long.
The nine planets are – Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune and Pluto. The solar system includes the sun, nine planets, and their moons. A planet is a huge object that orbits around the Sun. A planet does not make its own light or heat. Each planet has its own path, or orbit, around the Sun.
Useful for CBSE, ICSE, NCERT & International Students
Grade : 2
Subject : Evs
Lesson : Heavenly Bodies
Topic: Heavenly Bodies
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