Solar System
SOLAR SYSTEM
The earth and everything that orbits around the sun, including the eight planets and their satellite; the asteroids and comets; and interplanetary dust and gas. The term may also refer to a group of celestial bodies orbiting another star.
DIMENSION: The dimensions of the solar system are specified in terms of the mean distance from Earth to the Sun, called the astronomical unit (AU). One AU is equal to 150 million km (about 93 million mi).
THE SUN & THE SOLAR SYSTEM: The Sun is a typical star of intermediate size and luminosity. Sunlight and other radiation are produced by the conversion of hydrogen into helium in the Sun’s hot, dense interior. Although this nuclear fusion is transforming 600 million metric tons of hydrogen each second, the Sun is so massive that it can continue to shine at its present brightness for 6 billion years. This stability has allowed life to develop and survive on Earth.
“The Sun is so massive that it can continue to shine at its present brightness for 6 billion years.”
Our Solar System is the part of Milky Way Galaxy. According to the scientists there are billions of several Solar System in one Galaxy and there are billions of other Galaxies in this UNIVERSE.
UNIVERSE: This inflationary theory was develop in the 1970s to solve several mysteries still remaining in the universe as it was described by the big bang theory. Astronomers accept the theory that about 14 billion years ago the universe began as an explosive event resulting in a hot, dense, expanding sea of matter and energy. This event is known as the big bang.
GALAXY: A massive ensemble of hundreds of millions of stars, all gravitationally interacting, and orbiting about a common center. Astronomers estimate that there are about 125 billion galaxies in the universe. All the stars visible to the unaided eye from Earth belong to Earth’s galaxy, the Milky Way.
MILKY WAY GALAXY: The large, disk-shaped aggregation of stars, or galaxy, which includes the sun and its solar system. In addition to the Sun, the Milky Way contains about 400 billion other stars. There are hundreds of billions of other galaxies in the universe, some of which are much larger and contain many more stars than the Milky Way.
In our Solar System there are eight planets and one star name Sun. Our Solar System also includes several of asteroids and meteoroids. Eight Planets of Solar System devided into two parts (a) Inner planets (b) Outer Planets
INNER PLANETS OUTER PLANETS
(i) Mercury (i) Jupiter
(ii) Venus (ii) Saturn
(iii) Earth (iii) Uranus
(iv) Mars (iv)
INNER PLANETS: The inner planets are those planets which are closer to the sun and they are small in size and are composed primarily of rock and iron.
OUTER PLANETS: Outer planets are those which are far away from the sun and they are all huge in size and consist mainly of hydrogen, helium, and ice.
STAR: Any object that can produce its own light and energy. Our SUN is the only star in our Solar System and SUN contains 99.86% mass of our Solar System.
PLANETS: A planet is that which should have three qualities. They are,
(a) Planet should revolve around the sun.
(b) Planet should have spherical shape.
(c) Planet should clean its surrounding.
SATELLITE: Satellite is that body which revolves around the Planet.
ASTEROIDS: Asteroids fulfils only one condition of PLANETS. That is it revolves around the sun. It also have two more qualities whish are not similar from Planets which are they have very small mass and they don’t take spherical shape.
METEOROIDS: All objects that falls upon the surface of the earth called Meteoroids. They don’t move in particular orbit.
COMENTS: They have angular path mostly made up ice or crystal. Whenever they get closer to the sun they sublimate (converted into different gases). Forming a tail revolving around the sun in angular orbit with respect to the other planets.
EIGHT PLANETS OF THE SOLAR SYSTEM
MERCURY: Mercury orbits closer to the Sun than any other planet, making it dry, hot, and virtually airless. Although the planet’s cratered surface resembles that of the Moon, it is believed that the interior is actually similar to Earth’s, consisting primarily of iron and other heavy elements.
VENUS: Venus is the brightest object in our sky, after the sun and the moon. Swirling clouds of sulfur and sulfuric acid obscure Venus’s surface and inhibited study of the planet from Earth until technology permitted space vehicles, outfitted with probes, to visit it. These probes determined that Venus is the hottest of the planet, with a surface temperature of about 460º C (about 860º E). Scientist believe that a greenhouse effect causes the extreme temperature, hypothesizing that the planet’s thick clouds and dense atmosphere trap energy from the sun.
EARTH: An oxygen-rich and protective atmosphere, moderate temperatures, abundant water and a varied chemical composition enable Earth to support life, the only planet known to harbour life. The planet is composed of rock and metal, which are present in molten form beneath its surface.
MARS: The most detailed information available about Mars has come from unpiloted spacecraft sent to the planet by the United States between 1964 and 1976 from this data, scientists have determined that the planet’s atmosphere consists primarily of carbon dioxide, with small amount of nitrogen, oxygen, water vapor, and other gases. Because the atmosphere is extremely thin, daily temperatures can vary as much as 100 Celsius degree (190 Fahrenheit degree). In general, surface temperatures are too cold and surface pressure too low for water to exist in a liquid state on Mars. The planets resemble a cold, high-altitude desert.
JUPITER: Jupiter is the largest of the planes, with a volume more than 1,300 times greater that of Earth. Jupiter’s colorful bands are caused by strong atmosphere currents and accentuated by a dense cloud cover.
SATURN: Saturn, distinguished by its rings, is the second largest planet in the solar system. This processed Hubble Space Telescope image shows the planets could bands, storm and rings as they would appear to the human eye.
URANUS: Uranus’s blue-green color comes from the methane gas present in its cold, clear atmosphere. The dark shadings at the right edge of the sphere correspond to the day-night boundary on the planet. Beyond this boundary, Uranus’s northern hemisphere remains in a four-decade-long period of darkness because of the way the planers rotates.