2. WestRock Observatory

3. Earth Earth Stats: Radius = 6378 km Mass = 6 x 10 24 kg Density = 5.5 g/cm 3 Knowledge of the Earth's interior comes from seismology - the study of ground vibrations. Seismic waves can be reflected and refracted at boundaries, just like light waves. Using this fact, and other evidence, geologists have modeled the Earth's Interior.

4. Earth Above: Sumatran Earthquakes, April 2012, recorded at the CSU’s Coca-Cola Space Science Center

5. Earth Earth's structure has three primary layers. The Core About twice the size of the Moon, ~ 3400 km in radius. Composed mostly of iron & nickel The inner portion is solid. ~ Moon-sized. The outer portion is liquid (very dense). Convection + rotation = Dynamo effect - Magnetic field The inner core rotates slightly faster than the outer core. This may contribute to changes in Earth's magnetic field.

6. Earth The Mantle Layer of composed of dense rock and metal oxides. The mantle behaves as a plastic - properties of a solid but can flow under pressure. It is ~ 2900 km thick. Contains 65% of Earth's mass! (Density ~ 3.5 - 5.8 g/cm 3 ) The Crust A thin layer of silicates - granite(quartz) & basalt(feldspar) Has a relatively low density, 2.5 - 3.5 g/cm 3 Is only between ~ 10 km & 70 km thick

7. Earth Isotopes - atoms of an element with the same properties but different masses (more neutrons) Some isotopes are unstable and decay radioactively, releasing energy. Earth's interior is heated by radioactive decay. Core temp. = 7500 K, hotter than the Sun's surface! Differentiation - process by which a homogeneous body becomes stratified. This process gave Earth its layered structure.

8. Earth Above: Image of Earth and Moon together from NASA's Mars Reconnaissance Orbiter

9. Earth As the Earth was heated, it became molten. Heavier (more dense) elements sank. Lighter (less dense) elements rose. Tides - result from differences in gravitational force depending on distance. Tidal forces are differential forces. Aurora Borealis - Charged particles guided by Earth's magnetic field toward the North Pole, which hit our atmosphere causing it to glow. Northern Lights: Aurora Australis - southern lights Magnetosphere - region around the Earth in which the magnetic field keeps out charged particles flowing from the Sun.

10. The Moon

11. The Moon Moon Stats: Radius 1738 km = R m = ¼ R E Mass 7.4x1022 kg = M m = 1/81 M E (g M = 1/6 g E ) Density 3.34 gm/cm 3 = D m Albedo - ~11% Lunar Temperatures: 265 F in sun and -170 F in shade!

12. The Lunar Surface – WestRock Observatory

13. Lunar Rilles Hadley Rille

14. The Moon’s Features Highlands: ancient, heavily cratered terrain on the moon with higher average elevation. Maria: lowlands; large, flat, relatively crater-free plains on the moon. (singular = Mare) Younger terrain. (Latin = “Seas”) Mountain Ranges and Valleys: Formed by impacts and debris, not by tectonics as on Earth. Crater: circular depression caused by an impact. Some lunar craters ~ 300 km across!!! Deeper than Grand Canyon!!

15. Rayed Crater Mountain Range Mare or “Sea” Lunar Highlands

16. Rayed Crater

17. Central Peak Crater

18. The Moon Terminator: line separating day from night. Features more easily observed near the terminator. Longer shadows!! Lunar interior is differentiated. 1.It has a core with little or no iron (no magnetic field). 2.It has a large mantle where moonquakes occur. 3.It has a thick crust ~ 12% of its volume.

19. The Moon’s Origin Giant Impact: A Mars-sized impactor hit the proto- Earth off-center. Lighter debris from the impact was scattered into orbit and coalesced to form the Moon. Explains the Moon’s small iron core Explains the similarities AND the differences in isotope abundances Any volatiles would have been driven off the Moon by the heat of the collision. Collision is consistent with the present angular momentum of the Earth-Moon system.

20. Mysterious Mercury

21. Mercury Stats: Radius: 2439 km = 0.38 R E Mass: 0.055 M E (5.5% M E ) Density: 5.43 g/cm 3 Eccentricity of Orbit: 0.206 Average distance from the sun: 0.40 AU Maximum angle from the sun: 28 degrees Thus, the sun always rises or sets within ~ 2 hours of Mercury. Mercury always viewed in twilight or daylight or through thick turbulent air!

22. MESSENGER Spacecraft

23. Mercury The sidereal rotation period to be ~ 59 days. The revolution period is 88 days. (88/3 = 29.3) This is a 2:3 relationship. Albedo – the fraction of sunlight hitting a planet that is reflected. The albedo of a planet can be compared with the albedos of materials on Earth to determine of what material the surface of the planet is made. Mercury and the moon both have low albedos ~ 6%.

24. Mercury Mercury has a large core: Made of iron ~ 42% of its volume ~ 70% of its mass Mercury undergoes the greatest surface temperature variations in the solar system: during the day 427 C (800 F) at night -183 C (-300 F) Mercury has almost no atmosphere. Mercury has no moons.

25. Mercury Mercury’s Surface: 1.Heavily cratered in general 2.Has large, smooth plains (like Maria) 3.Has heavily cratered terrain (like Highlands) 4.Has lightly cratered intercrater plains in between. Mercury has very long scarps – lines of cliffs formed as Mercury’s core cooled and shrank – “wrinkles.” (Much longer than on the moon). Caloris Basin: 1300 km wide impact plain (like Mare Imbrium) bounded by 2 km high mountains.

26. Caloris Basin Image from MESSENGER Spacecraft

27. Mercury Mercury has a very slight atmosphere, consisting of Hydrogen, Helium (from the sun – solar wind), oxygen, argon, sodium and potassium (Sodium is the major constituent of Mercury’s atmosphere) Both sodium and potassium are found because of “sputtering” by solar wind). Mercury has a magnetc field = 0.1% BE – a partially molten core.

28. Beautiful Venus

29. Earth’s “sister” planet “Evil step sister” --Dr. C. Approximately equal sizes masses and densities. Venus Stats Radius – 6,052 km ~ 0.95 R E Mass – 0.82 M E Density – 5.24 g/cm 3 Orbital Period – 225 days (sidereal!!) Rotational Period – 243 days (retrograde!) (sidereal!) Ave. Orbital Radius: 0.7 AU Surface Temperature: ~ 900 F (would melt lead!!!)

30. Venus Spectra reveal the composition of the atmosphere: carbon dioxide ~96% (<0.1% on Earth); nitrogen nearly 4% with 0 2 and <1.0% H 2 0 Atmospheric pressure ~ 90 * P atm -E (due to CO 2 ) Where’s the CO 2 on Earth? It mixed with rain and minerals to form rocks such as limestone. Some organisms aided in this process. It is also trapped in our ocean waters. Venus has no oceans and no life; CO 2 is free!

31. Venus What happened to Venus’s H 2 O “Oceans”? A.Closer to the sun B.Lower atmosphere; hotter C.More water vapor rose to the upper atmosphere D.Solar UV broke it into H & O E.H is very light and easily escaped into space!! F.O combined with other gasses or with iron on the surface

32. Venus Clouds of Venus contain some H 2 O but much H 2 SO 4 – Sulfuric Acid Surface Temperature: intensity of emitted radiation increases with surface temperature (black body radiation) Radio waves penetrate Venusian clouds. Radio intensity yields surface temperature 900 F!! “Runaway Greenhouse Effect” Heat energy, released as I.R. is “trapped” by a nearly opaque atmosphere. Surface temperature must climb very high before escaping I.R. = (balances) incoming visible energy.

33. Mars, The Red

34. Mars MARS STATS Radius – 3397 km ~ 0.53 R E Surface Temperature -- -190 F to 80 F Mass – 0.11 M E (~ 1/10 M E ) Density – 3.94 g/cm 3 (Mars has a much smaller core and thicker crust than Earth!) Orbital Period – 687 days Rotational Period (sidereal) – 24 hrs. 37 min. Ave. Orbital Radius -- ~ 1.5 AU (semimajor axis = 1.523 AU) Tilt of the Axis – 25 degrees (Thus, Mars has similar seasons! Four seasons twice as long as Earth’s) Mars’ atmosphere ~ 1% P atm E. Mostly CO 2

35. How does Mars compare to the Earth ? The diameter of Mars is about half that of the Earth. Its mass is only 1/10 of Earth’s.

36. The Colossal Olympus Mons The largest volcano in the solar system. 375 miles across 16 miles high

37. The Valles Marineris The Mariner Valley 2500 miles long 125 miles wide 5 miles deep

38. Notice how these features resemble gullies made by flash flooding on the Earth. Here are some of the photographs from MGS.

39. Groundwater erodes away the topsoil forming an alcove. Water gushes downhill from the alcove cutting a channel, and clearing it of debris. Material swept out by the water forms an apron of debris at the bottom of the formation. Flash flooding creates a recognizable formation with 3 parts. These same structures are observed in the formations found on Mars. Currently, scientists find water to be the most likely cause.

40. The formations on Mars seem to be geologically recent.

41. Current Water on Mars - 2015 “Using an imaging spectrometer on NASA’s Mars Reconnaissance Orbiter, planetary scientists have detected signatures of hydrated minerals on warm slopes where seasonal flows, called recurring slope lineae, are seen on Mars.” - www.sci-news.com

42. Current Water on Mars - 2015 “We found the hydrated salts only when the seasonal features were widest, which suggests that either the dark streaks themselves or a process that forms them is the source of the hydration,” said lead author Lujendra Ojha, a Ph.D. student at the Georgia Institute of Technology. “In either case, the detection of hydrated salts on these slopes means that water plays a vital role in the formation of these streaks.” - www.sci-news.com

43. Mars Mars has two Moon. *Phobos (27 km across) orbits 7h 40 min. albedos ~ 6% *Deimos (15 km across) orbits ~ 30h albedos ~ 6%

44. Jupiter

45. Jovian Planets In the inner solar nebula, condensation of volatile elements was not possible because of the high temperatures. Only dust grains of metals, silicates, oxides, etc., were able to survive. But Jupiter (5.4 AU) is 5 times and Saturn (9.4 AU) is 10 times further from the Sun than is the Earth. Temperatures were much lower in this part of the solar nebula. Thus, volatile elements, including hydrogen & helium (the most abundant) became more important constituents of these planets.

46. Jovian Planets The Jovian planets probably formed in two steps: 1.Dust grains, coated with frozen gasses, accreted quickly to form 4 large protoplanets, each several times more massive than the Earth. 2.The strong gravitational attraction of these protoplanets accreted and retained large amounts of hydrogen, helium and other volatile elements. Rotation All of the gas giants rotate in less than 18 hours! Jupiter, the largest planet in the solar system, rotates in less than 10 hours! (About 9 hr 55 min). This rapid rotation makes the Jovian planets more oblate

47. Jovian Planets The Jovian planets experience differential rotation – different latitudes rotate at different rates. Example: Jupiter Near the poles 9 hr 55 min Near the equator 9 hr 50 min This differential rotation contributes to the banded appearance of the Jovian atmospheres. Belts and Zones – More easily visible on Jupiter and Saturn. Zones – bright bands; rising gas; the tops are approximately 20 km higher than the belts; ~ 10K colder than the belts. Belts – dark bands; falling gas; lower than the zones (thus, about 10K warmer – getting ready to rise up again!).

48. Jupiter Jupiter Stats Radius ~ 71,500 km ~ 11.2 R E Mass ~ 318 M E Revolution ~ 11.9 years Jupiter has at least one dark ring. Jupiter has at least 17 moons, including the 4 Galilean satellites – Io, Europa, Ganymede & Callisto Io very few impact craters  young surface hundreds of volcanic calderas – many are active sulfur dioxide plumes erupt 300 km high!

49. Jupiter Europa very smooth surface; only a few hundred meters variation in altitude  very young surface. Photographs of the surface resemble images of sea ice on Earth. There may be liquid H 2 O under the icy surface; 20 km – 50 km deep Comet Shoemaker-Levy 9 Collided with Jupiter in 1994 - Original body was 2 – 10 km in diameter. It was broken into 21 fragments by Jupiter’s gravity - Largest fragments 1 – 3 km in diameter. 1st time a collision between extraterrestrial bodies was “observed” by astronomers. The Great Red Spot of Jupiter – A high-pressure, anti-cyclone (rotates counter-clockwise in the Southern Hemisphere) that protrudes above the surrounding cloud tops.The Red Spot is about 12,000 km by 25,000 km (~ 2.5 to 3 D Earth ) & has lasted for more than 300 years!

50. Io

51. Comet Shoemaker- Levy 9

52. Saturn

53. The beautiful rings are easily visible Notice the gap in the rings - Cassini Division The shadow of the rings on the planet can be seen As many as six moons can be seen, including Titan

54. Saturn Radius ~ 60,300 km ~ 9.4 R E Mass ~ 95 M E Rotation ~ 10 hr 40 min Revolution ~ 29.4 years Saturn has thousands of tiny ringlets; combined they form the rings. Particle size ranges from 10 -2 m to 10 m (a few km sized). Saturn’s moons include Titan, second largest moon in the solar system.

55. Saturn’s rings are actually made up of thousands of smaller “ringlets.”

56. Uranus

57. Radius ~ 25,600 km ~ 4.0 R E Mass ~ 14.5 M E Rotation ~ 17 hr 14 min Revolution ~ 83.75 years Semimajor Axis ~ 19.2 AU Uranus has (at least) 9 rings. Discovered by Occultation

58. Neptune

59. Radius ~ 24,800 km ~ 3.9 R E Mass ~ 17.2 M E Rotation ~ 16 hr 7 min Revolution ~ 163.7 years Semimajor Axis ~ 30.1 AU Neptune has at least 3 rings. Discovered by Voyager Neptune’s Great Dark Spot: Half the size of Jupiter’s Great Red Spot Photographed in 1989 by Voyager 2

60. Pluto Photographed in 2015 by NASA’s New Horizons spacecraft

61. The Sun

62. Solar Observing At CSU Hydrogen Alpha

63. Solar Observing At CSU Calcium K

64. Ms. Getz 2 nd Grade Class – Forrest Road Elementary

65. Transit of Venus 2012 by ESS Major Kate Lodder

66. May 10, 2013 Annular Solar Eclipse Coen, Australia by CSU ESS Major Matt Bartow

67. Image featured on NASA’s APOD TWICE!!! apod.nasa.gov May 11, 2013 & April 26 2014 May 10, 2013 Annular Solar Eclipse Coen, Australia by ESS Major Cameron McCarty

68. Hyakutake & Hale-Bopp Spring 1996 Spring 1997

69. Meteor Showers

70. Tunguska