There Goes The Neighborhood Our Understanding of Life

There Goes The Neighborhood: Our Understanding of Life in the Solar System as Gathered by Space Probes I. A. Townsend Spring 2011

Part I: What We Believed

Space: The Final Frontier. . . http: //www. courier-journal. com/blogs/bruggers/uploaded_images/space 2 -735342. jpg

But Are We Alone?

Early Understandings Ancient societies: Muddled with religion Celestial bodies inhabited by Gods Talmud, Bible, Koran etc. all very vague on concept of other worlds Aristotle and Ptolemy Proponents of geocentric universe This makes other worlds unlikely! Ancient Greek thinking basically fell in line with this

New Outlooks • 16 th Century: Copernican heliocentric model • 1608: First refracting telescope Click to edit Master text styles Second level Third level Fourth level Fifth level http: //physicsworld. com/blog/galileo_04. jpg

Astronomy Explodes! Objects formerly undetected are now visible More planets than expected discovered in solar system Moons, Rings, Asteroids, etc. Neptune, discovered in 1846 http: //upload. wikimedia. org/wikipedia/commons/0/06/Neptune. jpg

Period of Speculation Many astronomers optimistic about intelligent life “Cosmic Pluralism” championed by Kant and Franklin Inspires art and literature postulation “We may pronounce each orb sustains a race / Of living things adapted to the place” -Sir Richard Blackmore, “The Creation: a Philosophical Poem in Seven Books” (1712)

Life on Mars? Click to edit Master text styles Second level Third level Fourth level Fifth level http: //mylifethroughthekeyhole. files. wordpress. com/2011/01/ziggy_stardust_high_line. jpg

Canal Network Late 19 th Century: Canals Discovered on Mars Lakes also appear to exist An intelligent society could exist / have existed http: //www. spacestationinfo. com/images/canals-mars. gif

Science, What A Buzzkill 1894: William Wallace Campbell spectroscopicallly analyzes Mars No substantial evidence of water or oxygen Canal building beings probably can’t survive By 1909, telescopes have improved enough to rule out canals too Merely optical illusions

Early 20 th Century “UFO” sightings popular Alien based religions pop up (e. g. Scientology) Belief that celestial bodies could be populated still strong http: //www. prlog. org/10265449 -dianetics-the-modern-science-of-mental-health. jpg

Part II: Age of Exploration

Space Age 1957: Sputnik 1 launched US Government and Citizens Panic NASA formed and first US satellite in 1958 http: //upload. wikimedia. org/wikipedia/commons/b/b 0/Sputnik_1. jpg

Space Probes Robotic spacecraft that leaves the gravity well of earth Once out of well: heliocentric orbit Different approaches to guided movement Fuel burning Gravitational slingshot Interplanetary transport network Lagrange points

Space Probes Three main types Probes that land on a planet Mars rovers, etc. Probes that orbit around a planet Pioneer Venus 1 Probes that operate in free space Pioneers 10 & 11, Voyagers 1&2, etc.

First Encounters 1960’s: Many probes designed to study nearby planets Both U. S. and Soviet missions Invaluable information gathered by both orbiters and landers Venera 7, 1970 http: //upload. wikimedia. org/wikipedia/commons/5/58/Venera_7_capsule. jpg

Outer Solar System Early atmospheric and surface data confirms life highly unlikely on Mercury, Venus or Mars Only hope: Outer solar system objects First probes: Pioneer 10 & 11 First clear view of Jupiter and Saturn Used to find safe passage through region Open many more questions for future exploration

Voyager Program Launched in 1977 Two identical craft “Grand Tour” Powered by Pu. O 2 Thermal energy Mission: Study outer planets, satellites, and eventually heliopause http: //en. wikipedia. org/wiki/File: Voyager. jpg

http: //en. wikipedia. org/wiki/File: Voyager_Program_-_spacecraft_diagram. png

Key Instrumentation Magnetometers Cosmic Ray Detectors IR/UV Spectrometers Photopolarimeter Digital tape recorder (62. 5 MB data storage) http: //rst. gsfc. nasa. gov/Sect 19_14. html

Primary Mission Close visits of Jupiter, Saturn, Uranus, and Neptune Pluto optional, not taken Data gathered on planet composition, observed weather phenomena, satellites, etc. Greatly expands our understanding of these planets

Primary Mission Flight Path Click to edit Master text styles Second level Third level Fourth level Fifth level http: //spacecraftkits. com/Voyager. Path. jpg

Interstellar Mission extension funded after 12 year primary mission complete Characterize solar influence on far reaches of solar system Find the heliopause boundary Outer limit of solar magnetic fields and wind Measure interstellar fields, particles, and waves unaffected by solar winds

Interstellar Mission Flight Path Click to edit Master text styles Second level Third level Fourth level Fifth level http: //rst. gsfc. nasa. gov/Sect 19_14. html

Future Voyager 1: Currently 17, 428, 000+ km out Will not be overtaken by any current human object Currently in heliosheath, will reach interstellar medium by 2015 Instruments are systematically shutting down to extend useful lifetime to 2020

Golden Record Society’s message to extraterrestrials Mounted on the side of both Voyagers Contains greetings from earth in 55 languages Music and sounds 115 analog images How could the record be played? Instructions on cover

Click to edit Master text styles Second level Third level Fourth level Fifth level http: //voyager. jpl. nasa. gov/spacecraft/images/Voyager. Cover. jpg_2 big. gif

Most Important Discoveries Atmospheric composition of all four gas giants 22 satellites undetected from earth Active volcanism (IO) Probable liquid water existence (Europa) Large scale storms on Neptune (Dark Spot) Peculiar Magnetospheres (Uranus, Neptune) Heliopause, Solar System asymmetry

Cassini-Huygens Launched in 1997 Designed specifically to orbit and study Saturn Modern instrumentation Hugens probe: first landing accomplished in outer solar system http: //lasp. colorado. edu/cassini/images/cassini_config_large. jpg

Huygens Collected atmospheric data GC/MS, Aerosol collectors, Surface composition analyzers Postulated “shoreline” landing http: //upload. wikimedia. org/wikipedia/commons/b/bc/Huygens_on_Titan. jpg

Gathered Data Hydrocarbon lakes not as common as thought Titanian haze made up of complex organic molecules, methane “Sand” made of ice grains, possibly water ice Atmosphere: Mostly N 2, remainder CH 4 + hydrocarbons http: //upload. wikimedia. org/wikipedia/commons/b/bc/Huygens_surface_color. jpg

What we learned Most important: Europa’s probable ocean Strong life potential Active volcanoes on IO Intense storms on Jupiter and Neptune Winds >1000 km/hr Detailed composition of Titan’s atmosphere Hydrocarbon lakes, Complex Molecule Haze

Future Work Solar system probes confirm that neighbors of any sort are improbable at best To find any life in solar system, we will need more invasive tactics Life forms might need to deviate entirely from our biological understandings

Philosophical Implications We have sent human artifacts millions of miles into space Voyager 1 might approach other solar systems in 40, 000 years Maybe we won’t have to find intelligent life, they will come to us At the very least, we might confuse some aliens long after extinction http: //upload. wikimedia. org/wikipedia/commons/5/58/Venera_7_capsule. jpg

Conclusion: Pale Blue Dot Click to edit Master text styles Second level Third level Fourth level Fifth level http: //upload. wikimedia. org/wikipedia/commons/7/73/Pale_Blue_Dot. png

Pictures from Voyager Click to edit Master text styles Second level Third level Fourth level Fifth level http: //voyager. jpl. nasa. gov/images/jupiter 2. gif

Pictures from Voyager Click to edit Master text styles Second level Third level Fourth level Fifth level http: //voyager. jpl. nasa. gov/images/jupiter/io. gif

Pictures from Voyager Click to edit Master text styles Second level Third level Fourth level Fifth level http: //voyager. jpl. nasa. gov/images/saturn. gif

Pictures from Voyager Click to edit Master text styles Second level Third level Fourth level Fifth level http: //upload. wikimedia. org/wikipedia/commons/9/94/Volcanic_crater_with_radiating_lava_flows_on_Io. jpg

Pictures from Voyager Click to edit Master text styles Second level Third level Fourth level Fifth level http: //voyager. jpl. nasa. gov/images/saturn/3 bg. jpg

Pictures from Voyager Click to edit Master text styles Second level Third level Fourth level Fifth level http: //voyager. jpl. nasa. gov/images/saturn/8 bg. jpg

Pictures from Voyager Click to edit Master text styles Second level Third level Fourth level Fifth level http: //voyager. jpl. nasa. gov/images/saturn/12 bg. jpg

Pictures from Voyager Click to edit Master text styles Second level Third level Fourth level Fifth level http: //voyager. jpl. nasa. gov/images/uranus/1 bg. jpg

Pictures from Voyager Click to edit Master text styles Second level Third level Fourth level Fifth level http: //voyager. jpl. nasa. gov/images/neptune/darkspot. gif

Pictures from Cassini Click to edit Master text styles Second level Third level Fourth level Fifth level http: //upload. wikimedia. org/wikipedia/commons/b/ba/Saturn_eclipse. jpg

Pictures from Cassini Click to edit Master text styles Second level Third level Fourth level Fifth level http: //upload. wikimedia. org/wikipedia/commons/2/25/Titan_globe. jpg

Pictures from Cassini Click to edit Master text styles Second level Third level Fourth level Fifth level http: //upload. wikimedia. org/wikipedia/commons/5/59/Enceladus_backdropped_by_ring_shadows_on_Saturn. jpg

Sources http: //www. exploratorium. edu/origins/arecibo/ideas/index. html http: //saturn. jpl. nasa. gov/ http: //lifeng. lamost. org/courses/astrotoday/CHAISSON/AT 306/HTML/AT 30606. HTM http: //library. thinkquest. org/03 oct/02144/text/mars/probes. htm http: //messenger. jhuapl. edu/the_mission/index. html http: //www. nasa. gov/mission_pages/voyagerf-20070820. html http: //www. nasa. gov/mission_pages/cassini/main/index. html http: //rst. gsfc. nasa. gov/Sect 19_14. html http: //en. wikipedia. org (Multiple Pages)