UNIVERSE & SOLAR SYSTEM

1. UNIVERSE & SOLAR SYSTEM Chapters 21 & 22 Test One Material

2. BIRTH OF ASTRONOMY • GEOCENTRIC - EARTH IS AT THE CENTER • ARISTARCHUS • HELIOCENTRIC - SUN CENTERED UNIVERSE • STILL LEARNING • Eric Idle

3. EARLY ASTRONOMERS • ERATOTHENES - FIRST TO MEASURE SIZE OF EARTH • HIPPARCHUS - STAR CATALOGUE - 850 • PTOLEMY - DEVELOPED MODEL OF THE UNIVERSE - PTOLEMAIC SYSTEM

4. MODERN ASTRONOMY • COPERNICUS - EARTH WAS A PLANET WITH SUN AT CENTER OF OTHER PLANETS • KEPLER - LAWS OF PLANETARY MOTION. ASTRONOMICAL UNIT OR (AU) MEASURED PLANETS DISTANCE TO SUN AND PERIOD OF REVOLUTION

5. PLANET AU YEARS • MERCURY 0.39 0.24 • VENUS 0.72 0.62 • EARTH 1.00 1.00 • MARS 1.52 1.88 • JUPITER 5.20 11.86 • SATURN 9.54 29.46 • URANUS 19.18 84.01 • NEPTUNE 30.06 164.80

6. GALILEO • TELESCOPE • 4 MOONS OF JUPITER • PLANETS WERE CIRCULAR DISKS • MOON’S SURFACE WAS NOT SMOOTH • SUNSPOTS

8. SIR ISAAC NEWTON • INERTIA - FIRST LAW OF MOTION THAT THE NATURAL TENDENCY FOR A MOVING OBJECT IS TO CONTINUE MOVING AT A UNIFORM SPEED AND IN A STRAIGHT LINE UNLESS ACTED UPON BY ANOTHER OUTSIDE FORCE • GRAVITY - ATTRACTIVE FORCE THAT IS DIRECTLY PROPORTIONAL TO MASS & INVERSELY TO DISTANCE

9. CONSTELLATION • AN APPARENT GROUP OF STARS ORIGINALLY NAMED FOR MYTHICAL CHARACTERS. PRESENTLY THE SKY IS DIVIDED INTO 88 CONSTELLATIONS

10. UNIVERSE ORIGIN? • HUGE EXPLOSION (BIG BANG) THREW MATERIAL OUTWARD IN ALL DIRECTIONS. MATERIAL BEGAN TO ATTRACT AND ROTATE (HAROLD UREY’S ROTATING DISK OR NEBULAR THEORY). MATERIAL COMBINED TO FORM SOLAR SYSTEMS. MATERIAL IN CENTER OF EACH SYSTEM REACHED 15 MILLION DEGREES F AND BEGAN TO GLOW • ALL THINGS ASTRONOMICAL

11. STARS • EACH SOLAR SYSTEM (STAR/SUN) IS CLUSTERED WITH BILLIONS OF OTHERS TO FORM GALAXIES ( 400 BILLION IN MILKY WAY GALAXY) • THERE MAY BE MILLIONS OF GALAXIES • GALAXIES ARE MILLIONS OF LIGHT YEARS APART

13. WHAT IS A LIGHT YEAR (DISTANCE)? • LIGHT TRAVELLING AT 186,000 MILES PER SECOND FOR AN ENTIRE YEAR • 5.8 TRILLION MILES • 5,800,000,000,000 MILES

14. BILLION AND TRILLION REALITY CHECK • IF YOU COULD PICK UP ONE PENNY PER SECOND HOW LONG TO PICK UP ONE BILLION? • 32 YEARS • WHAT ABOUT A TRILLION PENNIES? • 32,000 YEARS

15. OUR SOLAR SYSTEM • OUR SUN IS ONE OF 400 BILLION STARS THAT MAKE UP THE MILKY WAY GALAXY • YELLOW DWARF - COMPARED TO OTHER STARS IT IS AN AVERAGE STAR • 109 TIMES THE DIAMETER OF THE EARTH

16. Sun and stars

17. Sun

18. SUN STRUCTURE - SOLAR INTERIOR • CAN NOT BE DIRECTLY OBSERVED • HAS TEMPERATURES OF AT LEAST 15 MILLION DEGREES BUT MORE LIKELY 27 MILLION DEGREES FAHRENHEIT

19. SUN STRUCTURE - PHOTOSPHERE • THE SUN’S VISIBLE SURFACE • TEMPERATURES OF 10,000 DEGREES F • SUNSPOTS - DARK BLEMISHES THAT ARE COOLER THAN SUN’S SURFACE AND MAY EFFECT EARTH’S WEATHER • FACULAE - HOT SPOTS ON THE PHOTOSPHERE

20. SUN STRUCTURE - CHROMOSPHERE • LOWER OR INNER SOLAR ATMOSPHERE • HOT GASES WITH TEMPERATURES FROM 10,000 DEGREES F NEAR PHOTOSPHERE TO ALMOST 1 MILLION DEGREES F IN UPPER REGIONS

21. SUNSTRUCTURE - CORONA • OUTER SOLAR ATMOSPHERE • MAY EXTEND OUTWARD 620,000 MILES • TEMPERATURES GREATER THAN 1 MILLION DEGREES FAHRENHEIT

24. EARTH’S MOON • HAS NO ATMOSPHERE AND LACKS WATER • HAS A SURFACE WITH MANY CRATERS • THE MORE CRATERS IN AN AREA, THE OLDER THE SURFACE AREA

25. LUNAR SURFACE • MARE- DARK SURFACES OF MOON • HIGHLANDS - MOUNTAIN RANGES

27. LUNAR CYCLE - 29 1/2 DAYS • NEW MOON • WAXING CRESCENT • FIRST QUARTER • WAXING GIBBOUS • FULL MOON • WANING GIBBOUS

28. THIRD QUARTER • WANING CRESCENT • NEW MOON

30. MOON’S ORBIT AROUND EARTH • PERIGEE IS WHEN MOON IS CLOSEST TO EARTH AT ABOUT 221,000 MILES AWAY • APOGEE IS WHEN MOON IS FARTHEST AWAY FROM EARTH AT ABOUT 252,000 MILES

31. Lunar orbit

32. ECLIPSES • SOLAR ECLIPSE - MOON MOVES IN A LINE DIRECTLY BETWEEN EARTH & SUN. MOON’S ORBIT IS INCLINED ABOUT 5 DEGREES TO THE ELIPTIC PLANE OF EARTH/SUN • LUNAR ECLIPSE - EARTH MOVES BETWEEN SUN AND MOON

35. MOTIONS OF THE EARTH • ROTATION - MEAN SOLAR DAY VS. SIDERAL DAY [TIME IT TAKES EARTH TO MAKE ONE COMPLETE ROTATION WITH RESPECT TO ANOTHER STAR] • REVOLUTION

36. EARTH’S ORBIT AROUND SUN • AVERAGE OF 93 MILLION MILES • PERIHELION OCCURS ON JANUARY 3/4 WHEN EARTH IS 91 1/2 MILLION MILES FROM SUN • APHELION OCCURS ON JULY 3/4 WHEN EARTH IS 94 1/2 MILLION MILES FROM SUN

38. TERRESTRIAL PLANETS • COMPOSED OF DENSE ROCKY AND METALLIC MATERIALS WITH LITTLE OR NO ATMOSPHERE • MERCURY • VENUS • EARTH • MARS

39. JOVIAN PLANETS • GIANT PLANETS WITH LARGE AMOUNTS OF HYDROGEN AND HELIUM WITH THICK ATMOSPHERES • JUPITER • SATURN • URANUS • NEPTUNE • http://www.nineplanets.org/

40. Dwarf planets • New class of planets • Orbit the Sun • Not the only objects to occupy their area of space • Pluto is the prototype of this new category • Located in the Kuiper belt – a band of icy objects found beyond the orbit of Neptune

41. Dwarf Planets • Pluto • Charon • Eris - UB 313 [Xena] • Ceres

42. Comparison of Pluto, Earth, and other Kuiper Belt objects Figure 22.31

43. RELATIVE SIZE • Then the Earth is about 1.3 cm in diameter (the size of a grape). The Moon orbits about a foot away. The Sun is 1.5 meters in diameter (about the height of a man) and 150 meters (about a city block) from the Earth. Jupiter is 15 cm in diameter (the size of a large grapefruit) and 5 blocks away from the Sun. Saturn (the size of an orange) is 10 blocks away; Uranus and Neptune (lemons) are 20 and 30 blocks away. A human on this scale is the size of an atom; the nearest star would be over 40000 km away.

44. MERCURY • INNERMOST AND SWIFTEST PLANET • ALBEDO 0F 6% • DAYLIGHT & DARKNESS BOTH LAST 88 DAYS • TEMPERATURE RANGE OF -300F TO 800F • VERY LITTLE ATMOSPHERE

46. VENUS • SIMILAR IN SIZE, DENSITY AND MASS TO EARTH • THICK CLOUD OF CARBON DIOXIDE • SURFACE TEMPS OF 900F DUE TO GREENHOUSE EFFECT • ATMOSPHERIC PRESSURE IS 90 TIMES THAT OF EARTH • IF EARTH IS HEAVEN THEN VENUS IS HELL

49. MARS • LITTLE GREEN MEN, MARS ATTACKS, HG WELLES • WHITE POLAR ICE CAPS • HAVE GREAT RIFT VALLEY • VERY DRY PLANET • REDDISH ROCK, SAND AND SOIL • http://marsrovers.jpl.nasa.gov/home/index.html