Solar System By: Nina 2/12/09 Period 3

Sun is a star 1. A Source of Light and heat, the sun is a giant ball of glowing gas. The picture at left shows the sun with a huge solar prominence. Do not ever view the sun without special eye protection or filters. 2. Staring at the sun can permanently blind your eyes!The sun is mostly hydrogen with about 10% helium and other elements. 3. The nuclear reaction in the core changes the hydrogen to helium and releases tremendous amounts of energy as light, heat, x-rays, and high speed particles. As this happens the constant churning of the gases causes an intense magnetic field and other effects. Sunspots, solar winds, prominences and flares are some of these effects.

Mercury 4. Mercury is the closest planet to the sun. 5. Mercury is a battered and baked planet just larger than Earth's moon. Evidence of heavy bombardment from the chaos of the formation of the solar system is left in the hundreds of craters and resulting lava flows on this small, barren planet. 6. The largest crater is Beethoven at 643 km in diameter and is the largest in the solar system. 7. The largest feature, Caloris Basin, is 1300 km in diameter and was probably caused by an impact from an object larger than 100 km in diameter. 8. Some craters have ice in them even though the planet is so hot because the sun never reaches into the shadows due to the planet's tilt and orbit. 9. With no atmosphere, there is a temperature difference of about 600 degrees between the coldest spots and hottest spots on the planet. degrees 10. Mercury orbits the sun in about 88 Earth days but takes 58 Earth days to rotate once. On this planet a year takes a (Mercury) day and a half !

Venus 11. The brightest of all planets, Venus, is also known as the Morning Star and the Evening Star. 12. This planet is about the same size as Earth but is covered with impenetrable clouds of carbon dioxide and sulfur compounds. 13. Radar mapping of the planet shows lots of craters and that 90% of the landforms are volcanic. 14. Venus spins slowly retrograde (backwards west to east) in 243 days and takes about 225 days to orbit the sun. This makes the daytime about 115 days which can raise surface temperatures up to 464° C., it is the hottest plant of the solar system.

Earth 15. Earth, our home planet is teeming with life and wonderous things.

Mars 16.Mars has a very thin atmosphere, mostly carbon dioxide, but dust storms can cover the whole planet for months at a time. About every two years the Earth and Mars come close together. The planet has two moons, Diemos and Phobos.

Jupiter 17. Jupiter is the largest planet in the solar system. 18. Jupiter takes about 12 years to orbit the sun and rotates in about 10 hours. 19. This short Jupiter "day" is amazing since the planet is roughly 11 Earth diameters wide. 20. Unlike the rocky planets, Jupiter is a ball of dense hydrogen, helium, water, nitrogen and other gases over a tiny rocky core. 21. Powerful winds dominate the atmosphere with criss-crossing jet streams, lightning and huge hurricane-like storms like the Great Red Spot. This storm has been raging for over 300 years and is about 2 Earth diameters wide. The Great Red Spot can be seen on Jupiter along with four moons: Io (smallest), Europa, Callisto and Ganymede in this NASA image.

Saturn 22. Saturn and some of its moons can be seen in the composite image at left. 23. Four more moons were found in late 2000 and 9 more were discovered recently for a total of Scientists are tracking more objects that may be additional moons. 25. The Voyager missions found winds, magnetic field, auroras and lightning on the planet similar to Jupiter. 26. Also, the planet has light colored cloud bands (zones) and darker bands (belts) like the larger gas giant.The facinating ring system observed by Galileo in 1610 is only begining to be understood. 27. At first thought to be a solid ring it is now known to be thousands of water ice particles with some chunks as big as a small car. car 28. The rings are held in place by moons that "shephard" the particles and keep them in a series of ringlets. Some gaps like the Casinni Division separate the ringlets called the "A Ring", "B Ring" and so on. The Cassini/Huygens spacecraft will pass through between the "F" and "G" rings on its way to orbit Saturn (see below).

Uranus 29. The icy planet Uranus is a smaller version of Jupiter and not the small rocky bodies like Earth. 30. It have faint rings and a number of moons. Uranus takes some 84 years to orbit the sun. 31. It rotates on its side and so half the time one pole is toward the sun and then the other making each of the four seasons last about 20 years. 32. The faint bluish color of the planet is because the methane gas in the atmosphere absorbs red light and reflects blue light.

Neptune 33. Blue Neptune is one of the solar system's gas giants. 34. Unlike Earth, gas giants are mostly hydrogen, helium, and methane gases. hydrogen 35. The methane gas on Neptune gives the planet its blue color because the gas absorbs red light and reflects the blue back into space. 36. Although not seen in the image the planet has a set of very faint rings.The Great Dark Spot, the dark oval on the planet, was a storm like the Great Red Spot on Jupiter. Jupiter 37. The storm has disappeared since this image was taken by Voyager 2 according to Hubble Space Telescope data but another spot was found in a different place. Hubble Space TelescopeHubble Space Telescope 38. The atmosphere shows lots of activity including the white clouds of methane ice crystals seen in the image at left. 39. The unusual texture of one of Neptune's moons, Triton, reminds some people of a cantaloupe. 40. It is the largest moon to orbit retrograde (backwards) around a planet.

Pluto 41. Pluto is a small rocky object that lies at the very edge of the solar system. 42. The planet is so far out it takes light from the sun about 5 and one half hours to reach Pluto in contrast to the 8 minutes it takes to reach Earth. 43. Its orbit of about 248 years sometimes takes it inside Neptune’s orbit. 44. Pluto is so cold that nitrogen and oxygen, which we breathe so easily on Earth, become frozen solid. T 45. he planet is only about two-thirds the size of our moon and up until recently was the biggest known object in the Kuiper Belt.

Moon 46.The Moon is our only natural satellite. satellite

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