1. Prof. Geoff Marcy Jupiter and Europa Saturn and Enceladus

2. Textbook: The Cosmic Perspective Bennett et al. Order from Bookstore (takes a few days) to get kit for homework: MasteringAstronomy www.masteringastronomy.com Course ID: THEPLANETSFALL2012 Or get a used book, and purchase MasteringAstronomy online Reading this week and next week: Chapters 1 and 2 “Our place in the Universe “ & “Discovering the Sky” Homework: Due every Friday at 6pm Chapter 1 and Chapter 2 Assignments: due Friday Aug 31 at 6pm  Tuesday Sept. 4 @ 6pm 5% off for each wrong try. 2% for a hint.

3. 12 Discussion Sections start this week. All start this week. Review, Clarification, Homework Help. Sign up on Telebears 101 Wed 9-10A, 265 McCone Hall: Ben Legg 102 Wed 1-2P, 264 Evans Hall: Lea Hirsch 103 Wed 2-3P, 264 Evans Hall: Tess McEnulty 104 Wed 3-4P, 241 Cory Hall: Tess McEnulty 105 Th 2-3P, 264 Evans Hall: Lea Hirsch 106 Tu 2-3P, 264 Evans Hall: Tess McEnulty 107 Th 11-12P, 264 Evans Hall: Ryan Turner 108 Tu 11-12P, 264 Evans Hall: Ryan Turner 109 Tu 12-1P, 264 Evans Hall: Drummond Fielding 110 Th 12-1P, 264 Evans Hall: Lea Hirsch 111 W 11-12P, 264 Evans Hall: Ben Legg 112 Wed 12-1P, 264 Evans Hall: Drummond Fielding

4. Observing Project #1 Two choices B) Sketch where the Sun sets, relative to buildings. Wait 4-10 days. Sketch where the Sun sets again. Turn in both sketches, with time and date of observation. Write three sentences about any change in the position of sunset. Did it change? What direction? By how many degrees (approx.)? (The sun has an angular size of 0.5 degrees in diameter.) Due in class, Thursday Sept. 6 1 page maximum; Handwritten is fine. A ) Chart the position and shape of the moon. Sketch where the moon is located relative to nearby buildings. Also sketch the shape of the moon. Mark which direction is south. Note the time and day on the sketch. Wait 2-5 days, and do it again. (Hint: the moon is up now from 8pm-2am) Turn in both sketches, with time and date of observation. Write three to four sentences about any change you saw in the position or shape.

5. Course material on bSpace: http://bspace.berkeley.edu Syllabus Lecture slides Assignments: reading, homework, observing projects Course information

6. Last Time : :

7. The Solar System Inner Solar SystemOuter Solar System

8. The Solar System: Sun and 8 Planets Moons, Rings, Asteroids, Comets, and Dust

9. Milky Way Galaxy You Are Here 200 Billion Stars Photo taken from Earth

10. Our Sun moves relative to the other stars in the local Solar neighborhood. Our Sun and the stars orbit around the center of the Milky Way Galaxy every 230 million years. Our Milky Way Galaxy

11. Spiral Galaxies

12. Elliptical Galaxies

13. Irregular Galaxies

14. The Galactic Neighborhood 100,000 Light Years The ``Local Group” of Galaxies

15. The ``Local Group’’ of Galaxies

16. And outward… 10 Million Light Years

17. All matter and energy > 100 Billion Galaxies The Universe:

18. Astronomical Numbers Best to use Exponential Notation Exponential notation is handy: 10 N x 10 M = 10 (N+M) 10 3 = 1000 Thousand 10 6 = 1,000,000 Million 10 9 = 1,000,000,000 Billion 10 12 = 1,000,000,000,000 Trillion Also: 10 –3 = 1/1000 = 0.001 10 3 x 10 6 = 10 9 thousand million billion Example: B

19. How many stars in our visible Universe? A.10 12 (1 million million) B.10 18 (1 billion billion) C.10 22 D.infinite Interactive Quiz B

20. A.10 12 (1 million million) B.10 18 (1 billion billion) C.10 22 D.infinite Interactive Quiz Number of Stars in a galaxy: ~100 billion = 10 11 Number of galaxies in Universe: 100 billion = 10 11 B How many stars in our visible Universe?

21. There are 10 11 stars in the galaxy. That used to be a huge number. But it's only a hundred billion. It's less than the national deficit! We used to call them astronomical numbers. Now we should call them economical numbers. Richard Feynman B Federal Deficit each Year

22. In 2012, the National Debt is $15.9 Trillion U.S. Population = 311 x 10 6 people $15.9 x 10 12 / 3.11 x 10 8 = $5 x 10 4 = $50,000 per person = $15.9 x 10 12 Your Personal Debt: B

23. B Population of US: 300 million Cost per person: $787x10 9 / 3x10 8 = $2623

24. Distance, time and number : Radius of our Galaxy: 6,000,000,000,000,000,000 m = Radius of a Hydrogen atom: 0.00000000005 m = Time for one vibration of an oxygen molecule, O 2 : 0.00000000000001 s = Age of the Universe: 430,000,000,000,000,000 s = Scientific notation: 6 x 10 18 m 1 x 10 –14 s 4.3 x 10 17 s = 13.6 billion years 0.5 x 10 –10 m B

25. SI (Systeme International) Units Base units: 1 meter (m) length ~ 3.3 ft 1 kilogram (kg) mass ~ 2.2 lb 1 second (s) time B

26. SI (Systeme International) Units Base units: 1 meter (m) length 1 kilogram (kg) mass 1 second (s) time  MKS System of units and measure Sometimes easier to derive other units from these: km, g, ms, µs, … km = 10 3 m kilo g = 10 -3 kgkilo ms = 10 -3 smilli µs = 10 -6 smicro B

27. UNITS ARE IMPORTANT!!! Mars Climate Orbiter: Launch: 11 Dec. 1998 Orbit insertion: 23 Sep. 1999 Followed by: Loss of Communication WHY? Failed to convert from English units (inches, feet, pounds) to Metric units (MKS) $Billion error $Billion error B

28. Speed of Light and Light-travel time: C = 3 x 10 8 m/sec = 3 x 10 5 km/sec = 300,000 km/sec = 0.3 m/ns (1 ns = 10 -9 s) Light Year = 9 trillion km = 6 trillion miles Light Hour Light Minutes are unit of Distance: How far Light Travels in that interval of time 1 light second = 3 x 10 5 km 1 light ns = 30 cm ≈ 1 foot B

29. How long does it take the sun’s light to reach the Earth? Distance d = 1 AU = 1.5x10 11 m Speed of light c = 3x10 8 m/s Time B

30. Driving Curiosity Rover on Mars How long does it take to communicate with Curiosity ? B

31. How long does it take for radio waves (light) to reach Mars? A.Less than 1 second B.1 minute C.10 minutes D.1 hour Interactive Quiz B

32. How long does it take for radio waves (light) to reach Mars? A.Less than 1 second B.1 minute C.10 minutes D.1 hour Interactive Quiz B Earth-Mars distance: between 55 and 400 million km. t min = d min /v = 5.5×10 7 km / (3×10 5 km/s ) =1.8×10 2 s= 3 minutes t max = d max /v = 4.0×10 8 km / (3×10 5 km/s ) =1.3×10 3 s= 22 minutes

33. A Scaled Model of the Solar System 10 Billion x Smaller Sun’s diameter: 14 x 10 10 cm Reduce by 10 10 : 14 cm Earth diameter: 13000 km 0.13 cm Jupiter’s diameter: 150,000 km 1.5 cm Earth’s distance from Sun: 1 “Astronomical Unit” = 1 “AU” = 1.5 x 10 8 km 1 AU ?? cm Ans: 1500 cm = 15 meters 14cm 10 Scaled Down “Sun” A. 1.5 cm B. 15 cm C. 150 cm D.1500 cm

34. How large is the Solar System? Let’s view it to scale –Say the Sun is the size of a large grapefruit, 14 cm (6 inches) - then: G

35. Planet Dist (AU) Scaled Dist (m) Where? Mercury 0.4 6 6 rows back Venus 0.7 10 10 rows Earth 1.0 15 15 rows Mars 1.5 22 22 rows Jupiter 5 75 3/4 football field away Saturn 10 150 1.5 football field away Uranus 20 300 Sproul Plaza Neptune 30 450 Bancroft Ave Pluto 50 750 Durant Ave Oort Cloud 50,000 5 x 10 5 Oakland

36. . Saturn Saturn o Uranus o Neptune o Jupiter o You Are Here: Earth’s Orbit G.

37. How Far is the Nearest Star? Alpha Centauri d = 4 light years = 4 x 10 16 m Scales to: 4 x 10 6 m (~ 3000 mi) G “Sun” in S.F. “Alpha Centauri” In Washington D.C. Grapefruit-sized Sun in Berkeley Nearest Grapefruit: In Washington D.C.

38. Powers of Ten “Cosmic Voyage” The Movie G

39. How to deal with very large & small numbers Develop a useful arithmetic Exponential notation; convert between units Visualize using a sequence of images (movie) Use different sequences Visualize by way of a scale model Try different models G

40. A Universe in motion Contrary to our perception, we are not “sitting still.” We are moving with the Earth. – and not just in one direction The Earth rotates around it’s axis once every day. G

41. The Earth orbits around the Sun once every year. The Earth’s axis is tilted by 23.5 º ! G

42. Looking back in time Light, although fast, travels at a finite speed. It takes: –8 minutes to reach us from the Sun –8 years to reach us from Sirius (8 light-years away) –1,500 years to reach us from the Orion Nebula The farther out we look into the Universe, the farther back in time we see! B

43. The Origin of the Universe Most of the atoms in our bodies were created in the core of a star. (1) The two simplest atoms, H and He, were created during the Big Bang. B (2) More complex atoms were created in stars. (3) When the star dies, chemical elements are expelled into space, to form new stars and planets!

44. Galaxies appear to be moving away from us. The farther away they are, the faster they are moving. Space itself is expanding pace itself expands.

45. How old is the Universe? The Cosmic Calendar –if the entire age of the Universe were one calendar year –one month would be approximately 1 billion real years B

46. The Universe in a Day Look at the entire history of the Universe as though it took place in a single day. The present is at the stroke of midnight at the end of that day. Since it is about 13.5 billion years old, each hour will be ~0.5 billion years. A million years takes only a little over 7 seconds. The Big Bang (a dense, hot explosion) and the formation of H and He all take place in the first nanosecond. The Universe becomes transparent in about 2 seconds. The first stars and galaxies appear after about 2am. Our Galaxy forms at 4am. Generations of stars are born and die. B

47. The Universe in a Day The Solar System does not form until 3pm. The first life (bacterial) appears on the Earth by 4pm. Our atmosphere begins to have free oxygen at 7 or 8 pm, and this promotes the development of creatures which can move more aggressively and eat each other. Life does not begin to take on complex forms (multicellular) until 10:45pm. It moves onto land at 11:10. The dinosaurs appear at about 11:40, and become extinct at 11:52. Pre-human primates appear at around 14 seconds before midnight, and all of recorded history occurs in the last 70 milliseconds. Looking to the future, we can expect the Universe of stars to go on for at least another millennium (using the same time compression factor). After that, there are other ages of the Universe (not dominated by stars), which grow colder and more bizarre, and take place on astronomical timescales… B

48. What is the Earth’s velocity about the Sun? Radius of Orbit (1 AU): 150 x 10 6 km Circumference: 2 π x radius Distance around the Sun that the Earth travels: 2 π x (1.5 x 10 8 km) = 9 x 10 11 m Earth orbits the Sun once a year: 1 yr = 3 x 10 7 s Velocity = Distance/Time = 9 x 10 11 m / 3 x 10 7 s = 3 x 10 4 m/s = 30 km/s 110,000 km/hr or 75,000 miles/hr! B