THE SOLAR SYSTEM

1. THE SOLAR SYSTEM S.ARSALAN NADIR

2. About the Solar System • Our solar system consists of an average star we call the Sun, the planets Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, and Pluto. It includes: the satellites of the planets; numerous comets, asteroids, and meteoroids; and the interplanetary medium. The Sun is the richest source of electromagnetic energy (mostly in the form of heat and light) in the solar system. The Sun's nearest known stellar neighbor is a red dwarf star called Proxima Centauri, at a distance of 4.3 light years away. The whole solar system, together with the local stars visible on a clear night, orbits the center of our home galaxy, a spiral disk of 200 billion stars we call the Milky Way. The Milky Way has two small galaxies orbiting it nearby, which are visible from the southern hemisphere. They are called the Large Magellanic Cloud and the Small Magellanic Cloud. The nearest large galaxy is the Andromeda Galaxy. It is a spiral galaxy like the Milky Way but is 4 times as massive and is 2 million light years away. Our galaxy, one of billions of galaxies known, is traveling through intergalactic space.

3. Sun • The Sun is the star at the center of the Solar System. It is almost perfectly spherical and consists of hot plasma interwoven with magnetic fields.[10][11] It has a diameter of about 1,392,000 km, about 109 times that of Earth, and its mass (about 2×1030 kilograms, 330,000 times that of Earth) accounts for about 99.86% of the total mass of the Solar System.[12] Chemically, about three quarters of the Sun's mass consists of hydrogen, while the rest is mostly helium. Less than 2% consists of heavier elements, including oxygen, carbon, neon, iron, and others.[13]

4. Mercury • Mercury travels at an average rate of 47.36 kilometers per second 29.42 or miles per second in it's orbit around the Sun. Mercury's top speed is 58.98 kilometers per second 36.64  or miles per second which translates to 131934.50 MPH.As quick as Mercury travels, it spins quite slowly, taking 58.6 Earth days for Mercury to spin once on its axis.The fastest spinning planet is Jupiter, taking just under 10 hours to spin once on its axis, rotating at a speed of 28,273 MPH.

5. Venus • Venus and Earth are almost identical when it comes to their size. But that’s about the only way the two are alike. Venus’ atmosphere is made up almost entirely of carbon dioxide and thick sulfuric clouds are present on its entire surface. This is one reason why people could never land on Venus, they simply wouldn’t survive. In addition to that, the temperature on Venus is about 430 degrees Celsius, which also makes it impossible for inhabitation. There is also extreme atmospheric pressure on Venus, which is about 92 times greater than the pressure found on Earth.

6. Earth • Earth, our planet appears to be big and sturdy with an endless ocean of air. From space, astronauts often get the impression that the Earth is small with a thin, fragile layer of atmosphere. For a space traveler, the distinguishing Earth features are the blue waters, brown and green land masses and white clouds set against a black background

7. Mars • Mars is the fourth planet from the Sun and is commonly referred to as the Red Planet. The rocks, soil and sky have a red or pink hue. The distinct red color was observed by stargazers throughout history. It was given its name by the Romans in honor of their god of war. Other civilizations have had similar names. The ancient Egyptians named the planet Her Descher meaning the red one

8. Jupiter • Jupiter is the 5th planet from the sun. Jupiter is over twice as large as all the other planets combined. Jupiter's mass is 318 times that of the Earth. The equatorial diameter of Jupiter is 142,984 kilometers. Jupiter has 63 known moons, the largest being Ganymede. One year on Jupiter is 4,333.2867 Earth days or 11.86 Earth years. One Jupiter day is equal to 398.88 Earth days. The average temperature on Jupiter is -121 °C or -185.8 °F. Jupiter's atmosphere is about 86% Hydrogen and 14% Helium with traces of several other gases thrown in.

9. Saturn • Saturn is the sixth planet from the Sun and the second largest planet in the Solar System, after Jupiter. Saturn is named after the Roman god Saturn, equated to the GreekCronus (the Titan father of Zeus), the BabylonianNinurta and the HinduShani. Saturn's symbol represents the Roman god's sickle

10. Uranus • Uranus is the seventh planet from the Sun. It has the third-largest planetary radius and fourth-largest planetary mass in the Solar System. It is named after the ancient Greek deity of the sky Uranus the father of Saturn and grandfather of Zeus (Jupiter). Though it is visible to the naked eye like the five classical planets, it was never recognized as a planet by ancient observers because of its dimness and slow orbit.[16] Sir William Herschel announced its discovery on March 13, 1781, expanding the known boundaries of the Solar System for the first time in modern history. Uranus was also the first planet discovered with a telescope.

11. Neptune • Neptune is the eighth and farthest planet from the Sun in our Solar System. Named for the Roman god of the sea, 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 15 Earth masses and not as dense.[12] On average, Neptune orbits the Sun at a distance of 30.1 AU, approximately 30 times the Earth-Sun distance. Its astronomical symbol is ♆, a stylized version of the god Neptune's trident

12. Pluto • The diameter of Pluto is 2,274 km. Pluto is named after Hades, the god of the underworld. Pluto was discovered in 1930. Pluto is the only planet that hasn't been visited by a spacecraft. Pluto has a moon, Charon, which was discovered in 1978. The temperature on Pluto averages about -220 C. One day on Pluto is 6.39 Earth days. One year on Pluto is 247.7 Earth years. Although the farthest planet from the sun, it's elliptical orbit sometimes brings it closer than Neptune.