Solar System Lesson-2 PDF

TOPIC: THE SOLAR SYSTEM OVERVIEW: Solar system is in the Milky Way. It is called solar system because it is made up of star(Sun), and everything bound to it by gravity. ORDER AND FORMATION: Sun Four inner planets Asteroid belt Four gas giants Kuiper Belt THE SUN...

TOPIC: THE SOLAR SYSTEM OVERVIEW: Solar system is in the Milky Way. It is called solar system because it is made up of star(Sun), and everything bound to it by gravity. ORDER AND FORMATION: Sun Four inner planets Asteroid belt Four gas giants Kuiper Belt THE SUN The sun is the largest object in solar system. Contain the 99.8% of the solar system’s mass. Planets orbit the sun in oval-shaped paths called ellipses. THE PLANETS Merriam-Webster dictionary) a planet as “any of the large bodies that revolve around the Sun in the solar system.” International Astronomical Union (IAU) – a group of astronomers that names objects in our solar system – agreed on their own definition of the word “planet.” 1st - It must orbit a star (in our cosmic neighborhood, the Sun). 2nd - It must be big enough to have enough gravity to force it into a spherical shape. 3rd - It must be big enough that its gravity has cleared away any other objects of a similar size near its orbit around the Sun. DWARF PLANETS: Pluto and other dwarf planets are a lot like regular planets. Defined as objects that orbit the Sun, and are nearly round, but have not been able to clear their orbit of debris. So far, the IAU has only recognized five dwarf planets.  THE MOON: Naturally-formed bodies that orbit planets are called moons, or planetary satellites. ASTEROID BELT: A region of space between the orbits of Mars and Jupiter  ASTEROIDS Asteroids are rocky-metallic objects which range in size from about the size of pebbles Although they orbit the Sun, they are too small to be considered planets.  COMETS Comets are cosmic snowballs of frozen gases, rock, and dust that orbit the Sun. When frozen, they are the size of a small town. KUIPER BELT: A large region in the cold, outer reaches of our solar system beyond the orbit of Neptune. METEOROIDS-THESE ROCKS STILL ARE IN SPACE. IT IS A SMALL PIECE OF ASTEROID OR A COMET. METEORS: WHEN METEOROIDS ENTER EARTH’S AT HIGH SPEED AND BURN UP, THE FIREBALLS OR “SHOOTING STARS” ARE CALLED METEORS. METEORITES: WHEN SURVIVES A TRIP THROUGH THE ATMOSPHERE AND HITS THE GROUND.  The solar system has one star, eight planets, five officially named dwarf planets, hundreds of moons, thousands of comets, and more than a million asteroids.