DOC PREVIEW
ISU ENVI 360 - Ch09 THE TERRESTRIAL PLANETS

This preview shows page 1-2-3-4-30-31-32-33-34-61-62-63-64 out of 64 pages.

Save
View full document
View full document
Premium Document
Do you want full access? Go Premium and unlock all 64 pages.
Access to all documents
Download any document
Ad free experience
View full document
Premium Document
Do you want full access? Go Premium and unlock all 64 pages.
Access to all documents
Download any document
Ad free experience
View full document
Premium Document
Do you want full access? Go Premium and unlock all 64 pages.
Access to all documents
Download any document
Ad free experience
View full document
Premium Document
Do you want full access? Go Premium and unlock all 64 pages.
Access to all documents
Download any document
Ad free experience
View full document
Premium Document
Do you want full access? Go Premium and unlock all 64 pages.
Access to all documents
Download any document
Ad free experience
View full document
Premium Document
Do you want full access? Go Premium and unlock all 64 pages.
Access to all documents
Download any document
Ad free experience
View full document
Premium Document
Do you want full access? Go Premium and unlock all 64 pages.
Access to all documents
Download any document
Ad free experience
View full document
Premium Document
Do you want full access? Go Premium and unlock all 64 pages.
Access to all documents
Download any document
Ad free experience
View full document
Premium Document
Do you want full access? Go Premium and unlock all 64 pages.
Access to all documents
Download any document
Ad free experience
View full document
Premium Document
Do you want full access? Go Premium and unlock all 64 pages.
Access to all documents
Download any document
Ad free experience
View full document
Premium Document
Do you want full access? Go Premium and unlock all 64 pages.
Access to all documents
Download any document
Ad free experience
View full document
Premium Document
Do you want full access? Go Premium and unlock all 64 pages.
Access to all documents
Download any document
Ad free experience
View full document
Premium Document
Do you want full access? Go Premium and unlock all 64 pages.
Access to all documents
Download any document
Ad free experience
Premium Document
Do you want full access? Go Premium and unlock all 64 pages.
Access to all documents
Download any document
Ad free experience

Unformatted text preview:

Chapter 9The Terrestrial PlanetsTerrestrial Planet OverviewSlide 4Slide 5MercuryScarpsCaloris BasinChaoticTerrainMercury’s TemperatureMercury’s Atmosphere?Mercury’s InteriorAnother Large Impact HypothesisMercury’s Magnetic FieldMercury’s RotationSlide 16VenusThe Atmosphere of VenusSlide 19Slide 20The Greenhouse Effect on VenusThe Surface of VenusSlide 23Slide 24Surface FeaturesSlide 26Active Surface?Slide 28Venus is not Earth’s twin!First Image from VenusRotation of VenusSlide 32MarsSlide 34Vallis MarinerisThe Tharsis BulgeLargest Mountain in the Solar SystemSlide 38Polar Ice CapsSlide 40Dune FieldsWater on Ancient MarsAncient Lake?Mesas on MarsMartian River DeltaLake SedimentsThe Atmosphere of MarsSlide 48Slide 49Not a drop of rain…Morning FrostAncient Atmosphere of MarsSplash CratersWhere did the atmosphere go?The Martian InteriorThe Martian MoonsLife on Mars?Slide 58Why Are the Terrestrial Planets So Different?Role of Mass and RadiusRole of Internal ActivityRole of SunlightRole of Water ContentRole of Biological ProcessesChapter 9The Terrestrial PlanetsCopyright (c) The McGraw-Hill Companies, Inc. Permission required for reproduction or display.The Terrestrial Planets•The four terrestrial planets – Mercury, Venus, Earth, and Mars – have similar sizes and structure•These rocky worlds orbit in the inner part of the Solar System, too small and too warm to have captured massive hydrogen atmospheres like the Jovian giants•They have very few natural satellites – the Earth has the relatively large Moon and Mars has two small captured asteroids as moonsTerrestrial Planet Overview•Mercury – smallest terrestrial planet, looks like Moon (gray, bare, cratered), essentially no atmosphere•Venus – covered with deep sulfuric acid clouds in a dense CO2 atmosphere, hottest planet, immense volcanic peaks tower over desolate plainsTerrestrial Planet Overview•Mars – polar caps of ice and CO2, vast red deserts with craters and dunes, canyons, and dry river beds, ancient volcanoes, thin CO2 atmosphere•Earth – blue seas, white clouds and ice caps, red deserts, green jungles, mountainsTerrestrial Planet Overview•Planetary size coupled with distance from Sun is the cause for these differences!Mercury•Mercury’s radius is 1/3 and its mass 1/20 that of Earth•Circular craters cover the surface with the largest one being Caloris Basin with a diameter of 1300 km•Unlike the Moon where they are found almost exclusively in maria, congealed lava flows are found in many of Mercury’s old craters and pave much of its surfaceScarps•Enormous scarps (cliffs), formed as Mercury cooled, and shrank, wrinkling like a dried appleCaloris Basin•Largest crater basin on Mercury•1300 km across!•Odd trough-like patterns near the centerChaoticTerrain•“Chaotic terrain” feature opposite side of planet from Caloris Basin possibly caused by seismic waves generated by impact that created CalorisMercury’s Temperature•Mercury’s noon temperature at the equator (about 710 K = 820° F) and nighttime temperature (80 K = -320° F) are near the Solar System’s surface extremes•These extremes result from Mercury’s proximity to the Sun and its lack of atmosphereMercury’s Atmosphere?•Its low mass and proximity to the Sun do not allow Mercury to retain an atmosphere of any significance•Its proximity to the Sun suggests that Mercury never had a significant atmosphereMercury’s Interior•Mercury’s very high average density suggests that its interior is iron-rich with only a thin rock (silicate) mantle•Two possible reasons for a thin silicate surface:–Silicates did not condense as easily as iron in the hot inner solar nebula where Mercury formed–Rocky crust was blasted off by an enormous impactAnother Large Impact HypothesisMercury’s Magnetic Field•Mercury’s very weak magnetic field probably due to:–Small molten core–Slow rotation rateMercury’s Rotation•Mercury spins very slowly with a sidereal rotation period of 58.646 Earth days, exactly 2/3 its orbital period around the Sun of 87.969 Earth days•Consequently, Mercury spins 3 times for every 2 trips around the SunMercury’s Rotation•Such a ratio of periods is called a resonance–Mercury’s resonance is the result of the Sun’s tidal force on Mercury and its very elliptical orbit – the Sun cannot lock Mercury into a synchronous 1:1 rotation because of the high eccentricity of Mercury•Mercury’s solar day is 176 Earth days, longer than its year!•Because of Mercury’s slow rotation, near perihelion the Sun will briefly reverse direction in the Hermean skyVenus•Venus has a mass and diameter very close to that of Earth•However, the two planets have radically different surfaces and atmospheresThe Atmosphere of Venus•Reflected spectra and spacecraft measurements show the Venusian atmosphere is 96% CO2, 3.5% N2, and small amounts of H2O and other gasesThe Atmosphere of Venus•The clouds of Venus are sulfuric acid droplets with traces of water–The clouds are very high and thick, ranging from 30 km to 60 km above the surface–Surface cannot be seen through clouds–Some sunlight penetrates to surface and appears as tinged orange due to clouds absorbing blue wavelengthsThe Atmosphere of Venus•The atmosphere is extremely dense, reaching pressures about 100 times that of Earth’s•The lower atmosphere is very hot with temperatures of 750 K (900° F) at the surface, enough to melt lead•Spacecraft have landed on Venus, but do not survive longThe Greenhouse Effect on Venus•Large amounts of CO2 in the Venusian atmosphere create an extremely strong greenhouse effect•The effect is so strong Venus’s surface is hotter (750 K!) than Mercury’s although Venus is farther from the Sun•The high temperature and density of the atmosphere then create the high Venusian atmospheric pressureThe Surface of Venus•Ground features can be mapped with radar from Earth and spacecraft orbiting Venus since radar can penetrate the Venusian clouds•Venus’s surface is less mountainous and rugged than Earth, with most of its surface low, gently rolling plainsThe Surface of Venus•Only two major highlands, Ishtar Terra and Aphrodite Terra and about 8% of the surface, rise above the plains to form land masses similar to terrestrial continentsThe Surface of Venus•Ishtar Terra is about the size of Greenland and is studded with volcanic peaks – Maxwell Montes, the highest, is at 11 km


View Full Document

ISU ENVI 360 - Ch09 THE TERRESTRIAL PLANETS

Download Ch09 THE TERRESTRIAL PLANETS
Our administrator received your request to download this document. We will send you the file to your email shortly.
Loading Unlocking...
Login

Join to view Ch09 THE TERRESTRIAL PLANETS and access 3M+ class-specific study document.

or
We will never post anything without your permission.
Don't have an account?
Sign Up

Join to view Ch09 THE TERRESTRIAL PLANETS 2 2 and access 3M+ class-specific study document.

or

By creating an account you agree to our Privacy Policy and Terms Of Use

Already a member?