Lecture 1: Our Solar System

Transcription

1 Gibbous Moon (Waning) Betelgeuse Star (Appears Orange) Lecture 1: Our Solar System Professor Kenny L. Tapp Jupiter (Jovian Planet) INDIANAPOLIS, IN January 12, 2014 Orion Constellation StarMap Lite ios App (Free) Looking East-SouthEast Professor Kenny Tapp APOLLO PROGRAM MISSION CONTROL CONSOLE GEMINI CAPSULE MOCK Stafford Air & Space Museum, Weatherford, OK SATURN V ROCKET BOOSTER MODELS OF NASA ROCKETS POSSIBLE GEMINI ROCKET BOOSTER Oklahoma Professor Kenny Tapp

2 Recent Space News Overview of the Solar System Solar System includes... Sun Nine Eight planets & their satellites Asteroids, Comets, Meteoroids Overview of the Solar System A planet's orbit lies in an orbital plane Similar to a flat sheet of paper The orbital planes of the planets are inclined Planes of seven planets lie within 3 degrees of the Sun's equator Mercury's is inclined 7 degrees Pluto's is inclined 17 degrees Overview of the Solar System Two groups of planets occur in the solar system Terrestrial (Earth-like) planets Mercury through Mars Small, dense, rocky Low escape velocities Jovian (Jupiter-like) planets Jupiter through Neptune Large, low density, gaseous Massive Thick atmospheres composed of hydrogen, helium, methane, and ammonia High escape velocities Pluto not included in either group

3 Overview of the Solar System Planets are composed of Ices Ammonia (NH 3 ) Methane (CH 4 ) Carbon dioxide (CO 2 ) Water (H 2 O) Gases Hydrogen Helium Rocks Silicate minerals Metallic iron Solar System Ingredients The Sun dominates the Solar System Ingredient Sun Jupiter other planets everything else Percent of total mass 99.8% 0.1% 0.05% 0.05% The Terrestrial planets are made primarily of rock and metal. Mercury, Venus, Earth, & Mars. The terrestrial planets are: low in mass (< Earth mass) high in density (> 3900 kg/m 3 ). Water = 1000 kg/m 3 Air = 1 kg/m 3 Rock = 3000 kg/m 3 The Jovian planets are made primarily of hydrogen and helium. Jupiter, Saturn, Uranus, & Neptune: The Jovian planets are: high in mass (> 14 Earth masses) low in density (< 1700 kg/m 3 ). Jovian planets are made mainly of light elements like hydrogen and helium.

4 Pluto: The Oddity (Now a Dwarf Planet ) The Sun dominates the Solar System Pluto is very low in mass and moderate in density (about 2000 kg/m 3 ). It is surmised that Pluto is made of mixture of ice and rock. Most (but not all) planets rotate in the same direction (counterclockwise, seen from above the North Pole). All planets revolve in the same direction (counterclockwise, seen from above the North Pole). Uranus and Pluto are sideways, Venus is upside-down. Evolution of the Planets Nebular hypothesis Planets formed about 5 billion years ago Solar system condensed from a gaseous nebula Due to their surface gravities, Venus and Earth retained atmospheric gases Due to frigid temperatures, the Jovian planets contain a high percentage of ices As the planets formed, the materials that compose them separated Dense metallic elements (iron and nickel) sank toward their centers Lighter elements (silicate minerals, oxygen, hydrogen) migrated toward their surfaces Process called chemical differentiation Mercury Innermost planet Smallest planet No atmosphere Cratered highlands Vast, smooth terrains Very dense Revolves quickly Rotates slowly

5 Venus Second to the Moon in brilliance Similar to Earth in Size Density Location in the solar system Shrouded in thick clouds Impenetrable by visible light Atmosphere is 97% carbon dioxide Surface atmospheric pressure is 90 times that of Earth's Venus Surface Mapped by radar Features 80% of surface is subdued plains that are mantled by volcanic flows Low density of impact craters Tectonic deformation must have been active during the recent geologic past Thousands of volcanic structures Mars Called the "Red Planet" Two moons (captured asteroids) Phobos Deimos Atmosphere 1% as dense as Earth's Primarily carbon dioxide Cold polar temperatures (-193ºF) Polar caps of water ice, covered by a thin layer of frozen carbon dioxide Extensive dust storms with winds up to 270 kilometers (170 miles) per hour Mars Surface Numerous large volcanoes largest is Mons Olympus Less-abundant impact craters Tectonically dead "Stream drainage" patterns No bodies of surface water on the planet Possible origins Past rainfall Surface material collapses as the subsurface ice melts Several canyons Some larger than Earth s Grand Canyon Valles Marineras the largest canyon Valles Marineris canyon on Mars Figure 22.12

6 Jupiter Largest planet Very massive 2.5 times more massive than combined mass of the planets, satellites, and asteroids If it had been ten times larger, it would have been a small star Rapid rotation Slightly less than 10 hours Slightly bulged equatorial region Artist s view of Jupiter with the Great Red Spot visible Figure Jupiter Banded appearance Multicolored Bands are aligned parallel to Jupiter's equator Generated by wind systems Structure Surface thought to be a gigantic ocean of liquid hydrogen Great Red Spot In planet's southern hemisphere Counterclockwise rotating cyclonic storm Jupiter Moons At least 28 moons Four largest moons Discovered by Galileo Called Galilean satellites Each has its own character Callisto - outermost Galilean moon Europa - smallest Galilean moon Ganymede - largest Jovian satellite Io - innermost Galilean moon and is also volcanically active Saturn Similar to Jupiter in its Atmosphere Composition Internal structure Rings Discovered by Galileo in 1610 Composed of small particles (moonlets) that orbit the planet Most rings fall into one of two categories based on particle density Thought to be debris ejected from moons Origin is still being debated

7 The ring system of Saturn PASADENA, Calif. (Oct., 2009, NASA's Spitzer Space Telescope has discovered an enormous ring around Saturn by far the largest of the giant planet's many rings. The new belt lies at the far reaches of the Saturnian system, with an orbit tilted 27 degrees from the main ring plane. The bulk of its material starts about six million kilometers (3.7 million miles) away from the planet. Saturn's newest halo is thick its vertical height is about 20 times the diameter of the planet. It would take about one billion Earths stacked together to fill the ring. Figure Saturn Other features Dynamic atmosphere Large cyclonic storms similar to Jupiter's Great Red Spot Thirty named moons Titan the largest Saturnian moon Second largest moon (after Jupiter's Ganymede) in the solar system Has a substantial atmosphere Saturn Recent storm lasting more than 200 days, started early December, 2010.

8 Uranus Uranus and Neptune are nearly twins Rotates "on its side" Large moons have varied terrains Neptune Dynamic atmosphere One of the windiest places in the solar system Great Dark Spot White cirrus-like clouds above the main cloud deck Eight satellites Triton largest Neptune moon Orbit is opposite the direction that all the planet's travel Lowest surface temperature in the solar system (-391ºF) Atmosphere of mostly nitrogen with a little methane Volcanic-like activity Composed largely of water ice, covered with layers of solid nitrogen and methane Pluto Not visible with the unaided eye Discovered in 1930 Highly elongated orbit causes it to occasionally travel inside the orbit of Neptune, where it resided from 1979 thru February 1999 Moon (Charon) discovered in 1978 Average temperature is -210ºC Kuiper'Belt' objects:'' made%of%ice,% hundreds%of% kilometers% across.%(the% Kuiper%%% Belt %lies% beyond%the% orbit%of% Neptune.) Asteroids,%meteoroids,%comets,%and%Kuiper% Belt%objects%orbit%the%Sun. Asteroids:'made%of%rock%and%metal,%less%than% 1000%km%across.%(Most%asteroids%are%in%orbit% between%mars%and%jupiter.) Minor&members&of&the& solar&system& Asteroids Most%lie%between%Mars%and%Jupiter Small%bodies% %largest%(ceres)%is%about%620% miles%in%diameter Some%have%very%eccentric%orbits Many%of%the%recent%impacts%on%the%Moon%and% Earth%were%collisions%with%asteroids Irregular%shapes Origin%is%uncertain%

9 The&orbits&of&most&asteroids&lie&between&Mars& and&jupiter Figure Comets:'made%of%dirty% ice,%a%few%kilometers% across.%(comets%have% tails%of%gas%and%dust% when%they%come%near% the%sun.) Minor&members&of&the& solar&system& Comets OQen%compared%to%large,%"dirty%snowballs" ComposiSon Frozen%gases Rocky%and%metallic%materials Frozen%gases%vaporize%when%near%the%Sun% Produces%a%glowing%head%called%the%coma Some%may%develop%a%tail%that%points%away%from%Sun%due%to% RadiaSon%pressure%and%the Solar%wind%% Orienta8on&of&a&comet s&tail& as&it&orbits&the&sun Minor&members&of&the& solar&system& Comets Origin Not%well%known Form%at%great%distance%from%the%Sun Most%famous%shortXperiod%comet%is%Halley's% comet% 76%year%orbital%period PotatoXshaped%nucleus%(16%km%by%8%km)% Figure 22.25

10 &&&Comet&Hale>Bopp What s Wrong with this Exhibit? Figure Minor&members&of&the&solar&system& Minor&members&of&the&solar&system& Meteoroids Called%meteors%when%they%enter%Earth's%atmosphere A%meteor%shower%occurs%when%Earth%encounters%a% swarm%of%meteoroids%associated%with%a%comet's%path Meteoroids%are%referred%to%as%meteorites%when%they% are%found%on%earth% Perseids Meteor as viewed from ISS (Aug. 2011)

11 Meteoroids:'made%of%rock%and%metal,%less% than%300%meters%across.%(when%a% meteoroid%enters%earth s%atmosphere,%it% produces%a%meteor.) Meteor Crater Museum, Arizona In&the&News... Williamette Meteorite from Oregon, largest ever found in the US. Meteor&Crater,&Arizona allposters.com

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