The document provides information about the planets Mercury and Venus: - Mercury is the closest planet to the Sun. It has extreme temperature variations, ranging from 450°C during the day to -180°C at night. Mercury's core is disproportionately large, comprising 80% of its volume. - Venus is similar in size to Earth but has a dense carbon dioxide atmosphere that causes extreme greenhouse effects, heating its surface to over 450°C. Venus rotates clockwise in the opposite direction of most planets. Past Soviet Venera missions and NASA's Magellan spacecraft provided images and data of its volcanic landscape. - Both planets display phases as they orbit closer to the Sun than Earth. Their varying positions helped

1. Other Terrestrial Planets Mercury Venus Mars

2. Mercury Data http://www.vegaattractions.com/images/1mercury.gif Surface Gravity if Earth = 1 0.38 Planet Symbol (draw) Mass if Earth = 1 0.055 Length of Day 58.65 Earth days Diameter if Earth = 1 0.38 Length of Year (revolution around the sun) 87.97 Earth days Diameter at the Equator 3,031 miles Moons 0 Mean Distance from the sun 36,000,000 miles 0.4 AU

3. Discovery Naked eye planet It was first mentioned in written records of the Sumerians (3000 BC).

4. Mercury is only Slightly Larger than the Moon MERCURY OUR MOON

5. Mercury Visibility Briefly at sunset or sunrise Always close to the sun Inferior planet phases provided proof of Copernican solar system

6. Phases of Mercury Inferior planet (between sun and earth), displays phases Visible in telescopes

7. Phases of Inferior Planets http://www.polaris.iastate.edu/EveningStar/Unit1/Graphics/PicES1_6c.gif http://astromm.calstatela.edu/images/planets/larousse/Me_Phases.jpg

8. Eccentric Orbit Mercury’s orbit is one of the most elliptical, or eccentric Perihelion, 46 million km Aphelion, 70 million km

9. Planetary Eccentricities Which planet is most eccentric?

10. Mercury’s Lobsided Orbit www.astro.lsa.umich.edu/.../ mercury_layers.jpg

11. Mercury’s Temperature Extreme temp changes Dayside, 840 °F (450 °C) Nightside, -290 °F (-180 °C) Venus is the hottest planet

12. Surface Features Mercury resembles the moon Like the moon, it lacks a substantive atmosphere Mercury is heavily cratered and very old. Features: Scarps (enormous cliffs) Caloris Basin http://www.r-ds.com/images/ImagesOpera/beethoven.jpg

13. Discovery Scarp

14. Caloris Basin About 800 miles diameter Impact feature Resembles lunar maria (seas) Impact nearly shattered Mercury, created warped region at antipode http://www.record-producer.com/i/capacitor-microphone-sizzle.jpg

15. Mercury Names Features on Mercury named for famous writers, musicians, and painters. Craters Beethoven, Homer, Mark Twain, and Matisse 297 named features

16. Caloris Basin & Antipode

17. 16 Largest Craters on Mercury Beethoven Tolstoy Raphael Goethe Homer Vyasa Rodin Monet Haydn Mozart Bach Valmiki Renoir Wren Vivaldi Matisse

18. Shakespeare quadrangle of Mercury http://www.hollowaypages.com/images/CHANDOS2.jpg

19. Interior Large molten iron core Mercury’s metal core dominates most of the planet’s volume For earth’s core, only 17%, Mercury’s 80%

20. Mercury’s Day Mercury rotates three times in two of its years Rotation = 58.65 earth days Revolution = 87.97 earth days Mercury experiences only three days in two of its years. 3(58.65) = 175.95 2(87.97) = 175.94

21. Spacecraft Mariner 10: Visited Mercury in 1975. Photographed 45% of surface MESSENGER: Launched 2004 Perform 2 flybys Orbit Mercury starting in 2011 Homepage

22. Mariner 10’s Mercury (all images) http://nssdc.gsfc.nasa.gov/imgcat/mission_index.html#Mariner_10

23. MESSENGER Launched August 2004, reached Mercury January 2008 Will orbit and map Mercury http://ltpwww.gsfc.nasa.gov/ltp/images/Messengercraft.jpg

24. MESSENGER: Jan 2008

25. MESSENGER: Double-Ring Crater (1/14/08) http:// messenger.jhuapl.edu /

26. MESSENGER: “Spider” Crater

27. MESSENGER: Jan 2009

28. Water on Mercury!? Ice may exist in craters at Mercury’s poles Cratered areas never receive sunlight Similar deposits might exist on our Moon

29. Transits of Mercury Transit : The passage of an inferior planet (Venus or Mercury) across the face of the sun For Mercury, about 13 per century Last was November 2006 Spaceweather Link

30. Lore of Mercury Wednesday, or Woden’s Day, is named for Mercury Greeks: Evening appearance Apollo, morning appearance Hermes Romans: God of commerce, travel, and thievery Mercury was the quickest moving of the heavenly bodies, and the first to orbit earth in Ptolemy’s universe

31. Venus Data http://www.vegaattractions.com/images/1venus.gif Surface Gravity if Earth = 1 0.91 Planet Symbol (draw) Mass if Earth = 1 0.815 Length of Day 243.01 Earth days Diameter if Earth = 1 0.95 Length of Year (revolution around the sun) 224.70 Earth days Diameter at the Equator 7,521miles Moons None Mean Distance from the sun 67,200,000 miles 0.72 AU

32. Venus Venus : Roman goddess love and beauty Naked eye planet Venus is the brightest of planet as seen from earth, brightest object besides sun and the moon

33. Evening and Morning Star Evening or Morning Never visible late in evening Venus can extend about 45º to the east or west of the sun Venus stays in the sky much longer than Mercury which sets or rises near the sun Venus often pairs with the crescent moon for pretty scenes

34. Venus as Evening Star Venus as an evening star in the western sky after sunset

35. Venus as Morning Star Venus as a morning star in the eastern sky before sunrise

36. Changing Positions of Venus, Mercury http://www.nmm.ac.uk/upload/img/mv-orbit.jpg

37. Evening Star: Venus and Moon http://www.russellsastronomy.com/sky/April-June%20Planets.htm

38. Phases of Venus As an inferior planet (between sun and earth), Venus displays phases that resemble the phases of earth’s moon. Visible in telescopes Galileo first observed the phases of Venus in the early 1600s. He was the first astronomer to use a telescope to study the night sky.

39. Phases of Venus, cont. Galileo’s observation of the phases of Venus provided important evidence in favor of Copernicus’s heliocentric (sun-centered) theory of the solar system. Ptolemaic, or earth-centered solar system would only allow crescent phases Copernican system allows “full” Venus http://phyun5.ucr.edu/~wudka/Physics7/Notes_www/img152.gif Galileo’s Venus Sketches

40. Venus Phases, Earth and Sun Centered http://r2d2.stcloudstate.edu/~womack/astr/galileo/venuscop.jpg

41. Phases of Venus ( Click Here ) http://www.robertsilvey.com/notes/Venus02t.jpg

42. 8 year cycle & Synodic Period Venus orbits the sun 13 times in 8 earth years Result : We witness 5 Venus events every 8 earth years For example, 5 inferior conjunctions of Venus occur every 8 earth years Visually, appearances of Venus repeat every 8 years on virtually the same calendar date The time between successive conjunctions of a planet and the earth is termed the synodic period

43. Venus Synodic Period Venus Synodic Period = 584 days Compared to earth’s year, this is a 5:8 ratio 5 x 584 = 2920 days 8 x 365 = 2920 days Coincidence

44. 8 Year Cycle Image, draw a line between earth and Venus Outer edge is earth’s orbit Inner circle is Venus’s orbit Sun in center http://www.dreamhawk.com/venusearth.jpg

45. Retrograde Rotation Venus’s rotation is 243 earth days Also retrograde, rotates clockwise Mystery, perhaps an impact occurred?

46. Earth’s Sister Planet Venus 95% of earth’s diameter, 80% of earth’s mass Earth is heaven, Venus is hell

47. Atmosphere of Venus Venus is entirely covered with a thick atmosphere of Carbon Dioxide. Surface of Venus never visible from earth Magellan spacecraft used radar to map planet’s surface Immense greenhouse effect, Venus’s surface temperature equals 900ºF (hot enough to melt lead). Hotter than Mercury, twice as far from the sun High atmospheric pressure Sulfuric acid rain

48. Venus Greenhouse Effect http://www.uk2planets.org.uk/images/gallery/venus_greenhouse%20effect_esa.jpg

49. Cloudy Venus Venus is covered with a dense layer of clouds that hides its surface. Unlike the benign water vapor clouds on Earth, these clouds contain large amounts of sulfur dust and sulfur compounds, giving them a yellow-orange color. The clouds on Venus are made of concentrated sulfuric acid.

50. Spacecraft to Venus More than 20 space missions, American and Russian First Mariner 2, 1962. Soviet Venera 7, the first spacecraft to land on another planet, and Venera 9, returned the first photographs of the surface. Magellan mapped Venus (after 1990) http://members.aol.com/NYRocketScience/space/1962/s199-us-mariner2.jpg

51. Mariner’s Venus http://www.solarviews.com/browse/venus/venusmar.jpg 1962

52. Venus’s Surface (Venera) http://antwrp.gsfc.nasa.gov/apod/image/0311/venus_venera13.jpg

53. Magellan Global Views http://nssdc.gsfc.nasa.gov/photo_gallery/photogallery-venus.html

54. Venusian Landscape (Magellan)

55. Venusian Crater

56. Surface Features Gently sloped surface, mainly lava flows A few impact craters Several depressions such as Atalanta Planitia . Two large plateaus or highland areas ( Ishtar Terra and Aphrodite Terra ), most similar to earth’s continents Several large volcanoes such as the Sif Mons, not active Unique landforms such as pancake volcanoes, spider-like “arachnoids,” and coronae

57. Equatorial Venus

58. Venus Volcanism (all images) http://nineplanets.edu

59. Unusual Volcanism, Pancake Domes

60. Corona and Arachnoid

61. Early Fancies A swampy world with dinosaurs Pure fantasy

62. Transits of Venus Venus transits occur twice in 8 years, separated by over 120 years One of the rarest events in astronomy Last transit of Venus occurred June 8, 2004, the next will be in 2012 Previous transit had been in 1882

63. June 2004 Transit of Venus http://www.atmob.org/Photo/venus_2004/venus%20transit%208.JPG

64. Transits of Venus 8 June 9, 2255 122 June 11, 2247 8 December 8, 2125 105 December 11, 2117 8 June 6, 2012 June 8, 2004 Separation in Years Transit Dates

65. Feminist Planet Surface features named after women Ex : Amelia Earhart and Sacajawea, also ancient goddesses such as Ishtar and Aphrodite http://www.feministcampus.org/images/egreeting/rosie_the_riveter.jpg

66. “Personality” of Venus Rises quickly and is very brilliant High in the sky for a few months, sinks rapidly to disappear. Moves back and forth between morning and evening sky (about 9 months in each) Behavior interpreted in mythology (Maya, Sumerian) and Paradise Lost

67. Lore of Venus Sumerians : Goddess Ishtar, conjunctions represented the goddess's death and rebirth Greeks : Hesperus in the evening sky, Phosphorus in the morning sky Maya : God Quetazlcóatl (winged serpent) Maya Venus Calendar (Dresden Codex)

68. Goddess Ishtar http://www.unige.ch/lettres/antic/mesopotamie/ishtar.jpg

69. Maya Venus, Dresden Codex http://www-groups.dcs.st-and.ac.uk/~history/Diagrams/Dresden.jpeg

70. Maya Venus “Observatory” at Chichen Itza http://centros.edu.aytolacoruna.es/sfxabier/world_links/mexico_observatory.jpg

71. Lore of Venus: Paradise Lost Milton : The movement of Venus in the sky was used as a metaphor of the fallen angel Lucifer Central theme of epic poem Paradise Lost Published in 1674, the poem deals directly with ideas from the Bible

72. Paradise Lost http://www.clt.astate.edu/wnarey/Honors%20Seminars_files/Horror/summar3.jpg http://users.ox.ac.uk/~lina0897/emwo/images/big/PARADISE_LOST.jpg

73. Mars Data http://www.vegaattractions.com/astrology/symbols.html Surface Gravity if Earth = 1 0.38 Planet Symbol (draw) Mass if Earth = 1 0.107 Length of Day 24 hr. 37 min. 22.6 sec. Diameter if Earth = 1 0.53 Length of Year (revolution around the sun) 686.98 Earth days Diameter at the Equator 4,217 miles Moons 2 Mean Distance from the sun 141,500,000 miles AU

74. Red Planet God of War : Mars was the Roman god of war Discovery : Mars has been known since prehistoric times A favored location for science fiction stories Becomes very bright about every two years (opposition)

75. Spacecraft Mariner 4, 1965 No canals Viking landers, 1976 Twin landers, sampled soil, no life Mars Pathfinder, 1997 First rover mission Spirit & Opportunity, 2004 Twin rovers Phoenix, 2007 Martian Arctic, sampled soil and ice

76. Mariner 4 : No Canals (1965) http://mpfwww.jpl.nasa.gov/MPF/martianchronicle/martianchron2/issue2images/mariner4photo.jpeg

77. Viking (1976) http://www.hypography.com/bilder/viking_on_mars.jpg

78. Pathfinder (1997) http://users.bigpond.net.au/Nick/Mars/Pathfinder.jpg

79. Pathfinder (Mars or Arizona?) http://anw.com/mars/images/widescene.jpg

80. Mars Exploration In 2004 the Mars Expedition Rovers "Spirit" and "Opportunity" landed on Mars sending back geologic data and many pictures Spirit and Opportunity are still operating http:// marsrovers.jpl.nasa.gov/home/index.html

81. Spirit & Opportunity Panoramic Photos http://antwrp.gsfc.nasa.gov/apod/ap040318.html http://antwrp.gsfc.nasa.gov/apod/ap040114.html http://antwrp.gsfc.nasa.gov/apod/ap040204.html

83. Mars Phoenix, 2007 Phoenix, location near north pole of Mars

84. Mars Phoenix

85. Phoenix: Ice on Mars

86. Mars Missions

87. Cold Planet Climate : Range from –207ºF at the winter pole to 80ºF on the day side during summer Average temperature is –67ºF Most earthlike, despite cold Mars has earthlike tilt (25.19  ) and four seasons

88. Dusty Planet Atmosphere : Thin, mostly of carbon dioxide (95.3%) plus nitrogen (2.7%) and various other gases Strong winds and immense dust storms that can cover most of the planet and last for many months Dust devils

89. Mars Dust Storm

90. Martian Seasons Large ice cap made mostly of frozen carbon dioxide (dry ice) The dry ice melts, leaving a much smaller polar cap

91. Surface Features Surface: Nearly same land surface area as earth Old and cratered Resembles lunar highlands on earth’s moon Younger features such as rift valleys, ridges, hills, and plains. Unique and interesting, Olympus Mons, Valles Marineris

92. Impact Craters on Mars Most of these craters are found in the Southern Hemisphere, suggesting that the northern vastness has been resurfaced.

93. Olympus Mons http://www.physast.uga.edu/~jss/1010/ch10/mtoly.jpg

94. Tharsis Region Olympus Mons & clouds

95. Vallis Marineris (Viking)

96. Mars Volcanism Mars appears to lack plate tectonics, reason for huge volcanoes such as Olympus Mons. Plate motions wouldn’t allow such large piles of lava to accumulate No active volcanism has been observed on Mars

97. Martian Water Dry river and stream beds Large lakes or oceans may have existed Ice Caps : Permanent ice caps at its north and south poles. Mainly carbon dioxide (dry ice) with a small amount of frozen water ice Sedimentary rocks

98. Water Features Martian winding canyon, photographed by the Viking orbiter The Yangtze River in China has similar features

99. Ancient Waterways? An ancient lake A dried riverbed Sedimentation

100. Layers of rock laid down by water Hemetite black rocks, usually formed in water Gullies in crater walls

101. Sedimentary Layers from Water http://science.nasa.gov/headlines/images/mars_water/sediments.jpg

102. Chyrse, “Teardrop” Islands http://www.esa.int/images/mars_water_400.jpg

103. Martian Ice

104. Martian Life? Viking landers performed experiments to determine the presence of live, results inconclusive Some meteorites originated on Mars In 1996, NASA scientists announced the discovery of organic compounds and fossilized microorganisms in Martian meteorite ALH84001 Controversial

105. Viking Lander

106. Viking Life Experiment Trenches http://www.physics.uc.edu/~hanson/ASTRO/LECTURENOTES/ET/Earth/VikingMarsBig.jpg

107. Meteorite from Mars! http://www.universetoday.com/am/uploads/meteorite.jpg http://www.newscientist.com/data/images/ns/cms/dn8004/dn8004-1_440.jpg

108. Martian Life? (ALH84001) http://www.lpi.usra.edu/lpi/meteorites/Photomicrograph.gif

109. Fear & Panic Mars has two small moons Discovered in 1877 by Asaph Hall Phobos and Deimos—Fear and Panic—after two sons of the god of war mentioned in Homer’s Iliad . Small satellites (Phobos is only 24 miles across), resemble asteroids Similar to moons in Gulliver’s Travels (1726)

110. Phobos & Deimos http://www.sarkanniemi.fi/oppimateriaali/tahtiakatemia/kuvat/aurinkokunta/deimos_phobos.jpg http://perso.wanadoo.fr/pgj/phobos-deimos-061105.gif

111. Martian Names Martian Nomenclature : System of Schiaparelli. Imaginary and real place names from Greek and Roman literature Ex : Solis Lacus (Lake of the Sun), Aurorae Sinus (Bay of Dawn), Margaritifer Sinus (coast of India), Syrtis Major (Gulf of Sidra), Mare Tyrrhenum (Tyrrhenian Sea), Hellas (Greece), Eden and Elysium

112. Observing Mars Mars in the Night Sky : Every two years, Mars gets very bright and easily visible. Oppositions, earth and superior planet at minimum distance apart At opposition, superior planet rises in the east as the sun sets in the west

113. Oppositions of Mars Future Oppositions 7 Nov 2005 24 Dec 2007 29 Jan 2010 3 Mar 2012 8 April 2014 22 May 2016 27 July 2018 13 Oct 2020

114. Viking’s Face on Mars (1976) http://mcadams.posc.mu.edu/images%5Cface_mars.jpg

115. Face the Truth Apparent “face” on the Martian surface 22 years later, with improved technology the feature looks more natural

116. Alien with Spirit?

117. Life on Mars?