Mars Rockspacecraft missionexciting possibilities“On Mars Rover, Tools to Plumb a Methane Mystery” articlestructures of ice would indicate possibility for lifeJovan MoonsThe four large (Galilean) Satellites of JupiterIoEuropaGanymedeCallistoTitan“The Veil on Titan Lifted” articlehas many hydrocarbons (all the building blocks of life)very cold atmosphereIf life exists on Titan, it would be a very different kind of lifeammonia or methyl alcohol (a cold form of DNA) as its solventwould expand our concept of life1997 - CassiniMethods to Detect Extra Solar Planets1. Radio Signals from advanced civilization (Project SETI) DIRECT3 other primary methods *see worksheetReasons to Look for Life Elsewhere in the Universe1) If there is more than one life form then there could be millions in the Galaxy (we there are likely millions of Earth like planets) [we are not alone]2) To Communicate with very advanced life germs – learn new technologyHow to protect Earth etc [Project SETI]3) To possibly find out how life formed on EarthZone for Habitable for LifeGalactic Zonewe don’t think there are any life forms in this zone because it would be killed by radiationbig black holeMiddle of the GalaxyYou don’t see very heavy elements, the amount of heavy elements are going down rapidlySpiralBulgeThin DiskThick DiskThe Search of Extra Solar PlanetsExtra Solar Planets -10-20 parsecsSETI 1000 par secsDrake Equationwill be on testN = N* x Fs x Np x Fe x Fi x L/(lGalaxy)N = number of civilizations that will/can send us radio signals to Earth in the GalaxyN* = Number of stars in the galaxyFs = fraction of stars with long enough lifetimes and heavy element abundance and Earth like orbitsNp = Average number of “Earth like” planets per suitable starFe fraction of suitable planet where life appearswe don’t know this number but we do know that it probably isn’t very largeFi Fractions of planets that produce a civilization with interstellar communication capabilityL = Lifetime of CivilizationLg = Lifetime of galaxyvery generic formulaVery optimistic caseL = 10.000 yearsN* = 200 Bilion; Fs=Np=Fe=Fi = 1The Drake Equation is used to estimate the number of aliens who can send radio signals to earth from places in the galaxyYou are responsible to remember this equation only to understand the partsThe exact equation will be on the testReason we survived so many asteroids and extinctionsThe mammals were so smart and smallAfter dinosaurs died, the mammals roseAstro 5 Week 7 Lecture 11 22/02/2012 19:42:00← Mars Rock- spacecraft mission- exciting possibilities ←← “On Mars Rover, Tools to Plumb a Methane Mystery” article- structures of ice would indicate possibility for lifeJovan Moons- The four large (Galilean) Satellites of JupiteroIooEuropaoGanymedeoCallisto←← Titan- “The Veil on Titan Lifted” article- has many hydrocarbons (all the building blocks of life)- very cold atmosphere- If life exists on Titan, it would be a very different kind of life oammonia or methyl alcohol (a cold form of DNA) as its solventwould expand our concept of life1997 - Cassini Methods to Detect Extra Solar Planets- 1. Radio Signals from advanced civilization (Project SETI) DIRECT- 3 other primary methods *see worksheet←Reasons to Look for Life Elsewhere in the Universe- 1) If there is more than one life form then there could be millions in the Galaxy (we there are likely millions of Earth like planets) [we arenot alone]- 2) To Communicate with very advanced life germs – learn new technology oHow to protect Earth etc [Project SETI]- 3) To possibly find out how life formed on EarthZone for Habitable for Life- Galactic Zoneowe don’t think there are any life forms in this zone because it would be killed by radiationobig black hole- Middle of the GalaxyoYou don’t see very heavy elements, the amount of heavy elements are going down rapidly - Spiral- Bulge- Thin Disk- Thick DiskThe Search of Extra Solar Planets- Extra Solar Planets -10-20 parsecs - SETI 1000 par secs Drake Equation- will be on test- N = N* x Fs x Np x Fe x Fi x L/(lGalaxy)- N = number of civilizations that will/can send us radio signals to Earth in the Galaxy- N* = Number of stars in the galaxy- Fs = fraction of stars with long enough lifetimes and heavy element abundance and Earth like orbits- Np = Average number of “Earth like” planets per suitable star- Fe fraction of suitable planet where life appearsowe don’t know this number but we do know that it probably isn’t very large- Fi Fractions of planets that produce a civilization with interstellar communication capability- L = Lifetime of Civilization- Lg = Lifetime of galaxy- very generic formula - Very optimistic caseoL = 10.000 yearsoN* = 200 Bilion; Fs=Np=Fe=Fi = 1- The Drake Equation is used to estimate the number of aliens who can send radio signals to earth from places in the galaxy oYou are responsible to remember this equation only to understand the parts oThe exact equation will be on the test ←← Reason we survived so many asteroids and extinctions - The mammals were so smart and small- After dinosaurs died, the mammals rose22/02/2012 19:42:00←22/02/2012