Our Solar System

1. Our Solar System

3. The Sun – our very own star • The Sun is the center of our solar system • The word “solar” means “of the sun” • Our sun is a medium-sized star • Our sun is medium-hot, and yellow

5. The Sun dominates the Solar System

6. Spinning Planets • Period of Rotation: amount of time that an object takes to rotate once. (1 Day) • Period of Revolution ( Orbit ): time it takes an object to revolve around the sun once. (1 year) http://www.youtube.com/watch?v=97Ob0xR0Ut8&feature=related

7. End of Section Write your summary and Question. Be prepared to Share.

8. The Inner Planets

9. Terrestrial Planets • Mercury, Venus, Earth & Mars • “Earth-Like” Rocky Planets • Largest is Earth • Only in the inner solar system (0.4 to 1.5 AU) • Rocky Planets: small, dense and rocky • Solid Surfaces • Mostly Silicates and Iron • High Density: (rock & metal) • Earth, Venus, & Mars have atmospheres

10. Mercury • On Mercury you weigh only 38% of what you weigh on Earth. • Fastest orbiting planet • Planet nearest to the sun • One side of the planet can be 800 degrees Fahrenheit when the other can be -280 degree Fahrenheit at the same time. • Orbit Period 88 days • Rotation Period 59 days ( 1408 hours)

11. Mercury • The planet Mercury is the closest of the planets to the Sun, but it is not the hottest. • The surface of the planet Mercury is covered with craters. These craters have been created by eons of accidental encounters with asteroids and comets. This is because it does not have an atmosphere. • Mercury is just a little bit larger than Earth's moon. The surface of Mercury that faces the Sun can reach about 800 degrees Fahrenheit. On the other hand, the temperature on the nighttime side can plummet to almost -300 degrees Fahrenheit. This is because Mercury has little to no atmosphere to help regulate temperature.

13. Venus • On Venus you weigh only 91% of what you weigh on Earth. • Venus has 90 times the pressure of Earth and it’s the hottest planet. • Venus has volcanoes like Earth • Rotates in the opposite direction of Earth. • One time there were oceans before they boiled away. • Orbit Period 224 days • Rotation Period 242 days

14. Venus • Venus rotates in a prograde rotation. The sun comes up in the west and sets in the east. • Venus is the hottest planet because of its extremely thick atmosphere of carbon dioxide. • Venus is know as Earth’s twin. • Venus has no moons.

16. Earth • 23 hours and 56 min=1 Earth day (rotation) • 365 days =1 Earth year (revolution) • Earth is warm enough to keep most of its water from freezing and cold enough to keep it’s water from boiling • Temperature is between –13 degrees Celsius and 37 degrees Celsius

17. Earth • Earth is the only planet know to have life forms. • Earth has one natural satellite, the moon. • The ground you're walking on is recycled. Earth's rock cycle transforms igneous rocks to sedimentary rocks to metamorphic rocks and back again. • The oceans cover some 70 percent of Earth's surface, yet humans have only explored about 5 percent, meaning 95 percent of the planet's vast seas have never been seen.

19. Mars • Air Pressure on Mars is the same as 30 km above the Earth’s surface • Mars is in the form of ice. • Evidence that water was there at one time • Volcanic history like Earth. • It has the tallest mount of the planets (Olympus Mons) 3x’s size of Mt. Everest. • Orbital Period 687 days • Rotation Period 24. 6 hours

20. Mars • Mars’ red color is due to iron oxide, also known as rust, and has the consistency of talcum powder. Literally, the metallic rocks on Mars are rusting. • No human could survive the low pressure of Mars. If you went to Mars without an appropriate space suit, the oxygen in your blood would literally turn into bubbles, causing immediate death. • Mars has an enormous canyon named Valles Marineris (Mariner Valley) which is an astounding 2,500 miles long and four miles deep. As long as the continental United States, this gigantic canyon was likely formed by the tectonic “cracking” of Mars’ crust and is the longest known crevice in the solar system. • Although it is much colder on Mars than on Earth, the similar tilt of Earth’s and Mars’ axes means they have similar seasons. Like Earth's, Mars’ north and south polar caps shrink in the summer and grow in the winter. In addition, a day on Mars is 24 hours 37 minutes—nearly the same as Earth’s. No other planet shares such similar characteristics with Earth.

22. End of Section Write your summary and Question. Be prepared to Share.

23. Outer Planets

24. The Jovian Planets or Gas Giants • Jupiter, Saturn, Uranus & Neptune • Largest Planets: at least 15 times mass of Earth. • Only in the outer solar system (5 to 30 AU) • No solid surfaces (mostly atmosphere) • Low density • Gas Giants: (Jupiter & Saturn) • Thick H/He atmosphere, liquid hydrogen mantle, ice core • Ice Giants: (Uranus & Neptune) • Ice/rock core & mantle, thin H/He atmosphere

25. Jupiter • Largest planet in the Solar System • Has a Great Red Spot from a storm system that is more than 400 years old • Pressure is so great it would crush a spaceship. • Orbit Period 12 years • 9 hours and 54 min=1 Jupiter day (shortest day)

26. Jupiter • Jupiter is the largest planet in our Solar system. • Jupiter has many storms raging on the surface, most notably the big red spot which is the largest hurricane in our Solar System. It's been raging for over three hundred years. • Jupiter has many moons circling around it. Four of these moons are bigger than Pluto. • Jupiter also has a number of rings similar to that of Saturn but much less noticeable.

28. Saturn • 2nd Largest planet in the Solar System • 95 times more massive than earth. • Saturn has the largest rings of any planet, the rings are made of icy particles. • Most moons of any planets ( 47 known) • Orbit Period 29 years • Rotation Period 10 hours

29. Saturn • Many astronomers consider Saturn the most beautiful planet in the solar system because of its stunning rings. In fact, Saturn’s nickname is “the jewel of the solar system. • Saturn is the least dense planet in the solar system, and if there were a body of water large enough to hold Saturn, the planet would float. • Saturn rotates so fast (6,200 miles per hour) that the planet bulges at its equator and its poles are flat. It is the flattest (oblate) planet in the solar system. • Because Saturn spins on a tilt, it has seasons. Summer on Saturn lasts about eight Earth years.

31. Uranus • Discovered in 1781 • Uranus appears blue-green in color • It’s axis of rotation is tilted 90 degrees • Moons are named after Shakespearean plays and formed from other broken moons. • Orbit Period 84 years • Rotation Period 17 hours

32. Uranus • Uranus spins lying on its side (like a barrel), this is perhaps due to a large collision early in its formation. • Uranus’s atmosphere is mostly hydrogen but it also contains large amounts of a gas called methane. Methane absorbs red light and scatters blue light so a blue-green methane haze hides the interior of the planet from view. • It has only been visited one time- It has 27 moons- It can be seen without a telescope or binoculars.

34. Neptune • Discovered in 1846 • The atmosphere appears blue and is marked by large dark blue storms • Neptune has visual belts of clouds • It has a system of 5 rings and at least 13 moons • Orbit Period 165 years • Rotation Period 16 hours

35. Neptune • Neptune suffers the most violent weather in our Solar System. • Storms have been spotted swirling around its surface and freezing winds that blow about ten times faster than hurricanes on Earth make it the windiest planet. • Neptune is a large, water planet with a blue hydrogen-methane atmosphere and faint rings. • Neptune is covered in thin wispy white clouds which stretch out around the planet.

38. 21st Century Solar System

39. How long does it take to get to each planet? It depends a lot on the particular trajectory that you take. Usually, the trajectories are in the form of a 'great arc' that gracefully connects a launch time at Earth with a destination point. These arcs are usually many times longer that the straight-line distance between the two planets at a particular moment in time. For reduced-cost travel, astrodynamicists often rely on gravity assists 'Slingshot Orbits' from the inner planets to reach Jupiter, and by Jupiter to reach more distant worlds. These loop-de-loops add years of extra travel time to a mission. Let's assume for our calculations that we just take the simplest direct approach and use the minimum 'opposition' distance between Earth and a planet

40. Is there a REAL 9th Planet??? • A planet larger than Earth could be hiding in the cold, dark depths of the solar system. The presence of the planet, which would lie far beyond Pluto, is betrayed by the curious orbits of a handful of distant icy worlds. • As described Wednesday in the Astronomical Journal, the gravitational signature of a large, lurking planet is written into the peculiar orbits of these farflung worlds. Called extreme Kuiper Belt Objects, the misbehaving bodies trace odd circles around the sun that have puzzled scientists for years. • It’s tantalizing evidence that a ninth large planet might live in the solar system, though the world hasn’t been detected yet.

41. It’s tantalizing evidence that a ninth large planet might live in the solar system, though the world hasn’t been detected yet. If there’s going to be another planet in the solar system, I think this is it, It would be quite extraordinary if we had one. Fingers crossed. It would be amazing. The team calculated that the planet, if it’s there, would be about 10 times as massive as Earth, or roughly three times larger. That makes it a super-Earth or mini-Neptune—a type of planet the galaxy is incredibly efficient at assembling, but which has been conspicuously absent from our own neighborhood. And it’s really far away. Simulations suggest that the planet’s closest approach to the sun would be roughly 200 to 300 times farther out than Earth’s. Its most distant point? That’s way out in the hinterlands, between 600 and 1,200 times farther than Earth. This thing is on an exceptionally frigid, long-period orbit, and probably takes on the order of 20,000 years to make one full revolution around the sun.

44. End of Section Write your summary and Question. Be prepared to Share.

45. Pluto • Discovered 1930 • Mystery Planet • Farthest from the sun • Recently changed from a being considered a planet to a dwarf planet. • Orbit Period 248 years • Rotation Period 6.4 days

46. Is Pluto a Planet? What to consider? • Size? • Shape? • Orbit? • What is it made of?

47. IAU Definition of a Planet In 2006, the International Astronomical Union (IAU) came up with the following definition of a planet: • orbits the Sun • has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium shape (i.e., it is spherical), • has cleared the neighborhood around its orbit, • is not a satellite

48. IAU Definition of a Dwarf Planet In 2006, the International Astronomical Union (IAU) came up with the following definition of a dwarf planet: • orbits the Sun • has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium shape (i.e., it is spherical), • has not cleared the neighborhood around its orbit, • is not a satellite

50. Dwarf Planets • A dwarf planet is a celestial body massive enough to be spherical, in orbit around the Sun, which are not satellites. The crucial factor dividing a planet from a dwarf planet is that a planet must have succeeded in clearing the area of its orbit from debris and other objects, whereas a dwarf planet has not.