Ss Project For Planet

DEGITAL EQULIZTER PROGRAM S,S Project “Planet” (By ) RAKHI PANDAY S,S MISTRESS GOVT GIRLS SEC SCHOOL SAMRAI JALANDHAR

“PLANET” What is planet? Planet, any major celestial body that orbits a star and does not emit visible light of its own but instead shines by reflected light. Smaller bodies that also orbit a star and are not satellites of a planet are called asteroids or planetoids. In the solar system, there are nine planets: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, and Pluto. Planets that orbit stars other than the Sun are collectively called extrasolar planets. Some extra solar planets are nearly large enough to become stars themselves. Such borderline planets are called brown dwarfs. See also Planetary Science.

Types of planet (1) Uranus (planet), major planet in the solar system, seventh planet from the Sun. Uranus revolves outside the orbit of Saturn and inside the orbit of Neptune (see Solar System). The average distance from Uranus to the Sun is 2.87 billion km (1.78 billion mi). Uranus has an inner rocky core that is surrounded by a vast ocean of water mixed with rocky material. From the core, this ocean extends upward until it meets an atmosphere of hydrogen, helium, and methane. Uranus has 11 known rings and 27 confirmed moons. The mass of Uranus is 14.5 times greater than the mass of Earth, and its volume is 67 times greater than that of Earth. The force of gravity at the surface of Uranus is 1.17 times the force of gravity on Earth. Because of its great size and mass, scientists classify Uranus as one of the giant or Jovial (like Jupiter) planets—along with Jupiter, Saturn, and Neptune. (2) Saturn (planet), sixth planet in order of distance from the Sun, and the second largest in the solar system. Saturn's most distinctive feature is its ring system, which was first seen in 1610 by Italian scientist Galileo, using one of the first telescopes. He did not understand that the rings were separate from the body of the planet, so he described them as handles (ansae). The Dutch astronomer Christiaan Huygens was the first to describe the rings correctly. In 1655, desiring further time to verify his explanation without losing his claim to priority, Huygens wrote a series of letters in code, which when properly arranged formed a Latin sentence that read in translation, “It is girdled by a thin flat ring, nowhere touching, inclined to the ecliptic.” The rings are named in order of their discovery, and from the planet outward they are known as the D, C, B, A, F, G, and E rings. These rings are now known to comprise more than 100,000 individual ringlets, each of which circles the planet. (3) Jupiter (planet), fifth planet from the Sun and the largest planet in the solar system. The fourth brightest object in Earth’s sky, after the Sun, the Moon, and Venus, Jupiter is more than three times brighter than Sirius, the brightest star. Due to its prominence in the sky, the Romans named the planet for their chief god, Jupiter. (4) Venus (planet), one of the planets in the solar system, the second in distance from the Sun. Except for the Sun and the Moon, Venus is the brightest object in the sky. The planet is called the morning star when it appears in the east at sunrise, and the evening star when it is in the west at sunset. In ancient times the evening star was called Hesperus and the morning star Phosphorus or Lucifer. Because of the distances of the orbits of Venus and Earth from the Sun, Venus is never visible more than three hours before sunrise or three hours after sunset. (5) Mercury is the innermost and smallest planet in the solar system, orbiting the Sun once every 88 days. It ranges in brightness from about −2.0 to 5.5 in apparent magnitude, but is not easily seen as its greatest angular separation from the Sun (greatest elongation) is only 28.3°. It can only be seen in morning or evening twilight. Comparatively little is known about the planet: the only spacecraft to approach Mercury was Mariner 10 from 1974 to 1975, which mapped only 40%–45% of the planet’s surface.

(6) Earth is the third planet from the Sun and is the largest of the terrestrial planets in the Solar System, in both diameter and mass. Home to the human species, it is also referred to as "the Earth", "Planet Earth", "Gaia", "Terra", "the World", and "the Blue Planet". The Earth is the first planet known to have liquid water on the surface and is the only place in the universe known to harbor life. Earth has a magnetic field that, together with a primarily nitrogen-oxygen atmosphere, protects the surface from radiation that is harmful to life. The atmosphere also serves as a shield that causes smaller meteors to burn up before they strike the surface. (7) Mars is the fourth planet from the Sun and is known as the Red Planet due to its reddish appearance as seen from Earth. The planet is named after Mars, the Roman god of war. A terrestrial planet, Mars has a thin atmosphere and surface features reminiscent both of the impact craters of the Moon and the volcanoes, valleys, deserts and polar ice caps of Earth. It has the highest mountain in the solar system, Olympus Mons, and the largest canyon, Valles Marineris. Mars' rotational period and seasonal cycles are also similar to those of the Earth. (8) Neptune is the eighth and farthest planet from the Sun in our solar system. It is the fourth largest planet by diameter and the third largest by mass; Neptune is 17 times the mass of Earth and is slightly more massive than its near twin Uranus, which is 14 Earth masses, but Neptune is slightly smaller in volume due to its higher density. The planet is named after the Roman god of the sea. (9) Pluto is the second-largest known dwarf planet in the Solar System and the tenth-largest body observed directly orbiting the Sun. originally considered a planet, Pluto has since been recognized as the largest member of a distinct region called the Kuiper belt. Like other members of the belt, it is primarily composed of rock and ice and is relatively small; approximately a fifth the mass of the Earth's Moon and a third its volume. Pluto is smaller than seven moons in the Solar System

Bibliography 1. Text book of ninth class referred. 2. Picture downloads from internet www.Google.com.