Study Points - MCTCteach

Study Points What is the Copernican Principle?What are the basic requirements for life as we know it?Describe the characteristics of a habitable environmentWhat biomarkers do we look for in the search forevidence of life beyond our solar system? What is the Fermi paradox, and what are some possiblesolutions to it? List efforts to communicate with other civilizations(listening and talking)

Life in theUniverse AstrobiologyAre we alone in theuniverse?Searching for LifeNASA Graphic Novels about Life in the aphic-histories/

Lucky Accidents from last lecture1. Density fluctuations need to be “just right” Too small: Gravity too weak and no galaxies form Too large: Black hole universe with radiation notallowing humans2. Finely balanced between expansion andcontraction3. Matter needed to be greater than anti-matter formatter to take over and us to exist4. The force of gravity has to be just right to formstars of our Sun’s mass5. And many more perfect balances

Slido.com Class Poll Enter code: #K261 Answer this: Do you think life exists outside of Earth?

The Copernican Principle* Earth is not a privileged/special place in the universe* Not the center of the solar system Not the center of the universe Not the only planet Many stars like our Sun From Galileo to Hubble,science proves the universe ismuch bigger than us So why should we be the only planet with life? Yet to be answered: Is organic biochemistry likely orunlikely in the universe?

Requirements for Life:What makes life possible? All life we know uses the same basic elements* Carbon Hydrogen Nitrogen Oxygen Phosphorus Sulfur Arranged in amino acids: the building blocks of life Amino acids based on carbon bonds (organic molecules) Biology also requires liquid water* Energy input*

Where do we find these materials?Everywhere!Trillions of timesEarth’s water ingiant dust cloudsComplex organic moleculesfound near galactic centerGlycine (amino acid) andphosphorus found on RosettaComet

What makes Earthgood for life? Moderate temperatures Stable for a long time(a few billion years) Magnetosphere protects us from harmful radiation Moon makes tides (allows for slow transition from waterto land) Moon protects us from asteroids So does Jupiter Star not too hot (short-lived), not too cool and stormy Solid surface Rocky composition means elements are plentiful

But maybe nice isn’t necessaryExtremophiles have been found living at: -13 F 250 F 1000 times normal pressure 1000 times human radiation tolerance pH equivalent to bleach 10 million times more acidic than humanblood

Characteristics of a Habitable EnvironmentWhat do we look for? Liquid water * Energy * Base materials * Stable environment *Habitable does NOT mean inhabited

Possible Habitable EnvironmentsCurrent Best Bets in Our Solar System Mars Europa – moon of Jupiter Enceladus – moon of Saturn Titan – moon of Saturn

Current Best Bets: Mars Recurring slope lineae:where water still flows Mudstone: rocks thatformed in or under waterCuriosity rover also foundorganic molecules andpockets of methaneLife underground? On thesurface? Currently looking

Current Best Bets: Europa and EnceladusEnergy: geothermal from tidal stresseson EuropaWater: undergroundoceans on EuropaMaterials: organic materialsspotted in plumes fromEnceladus

Current Best Bets: TitanAtmosphere: onlymoon to have a denseatmosphereWater: no, but surfaceoceans & lakes ofmethane/ethaneMaterials:covered in organicmaterials,including les-titan

Habitable Environments BeyondOur Solar System Focused on the Habitable Zone: where liquid wateris possible on a planet’s surface (Goldilocks zone)

Habitable Zone May change throughout a star’s lifetime Atmosphere may affect it (too much or too little) Doesn’t help if planet has no water (like Venus) Habitable Exoplanet Catalog: Watch/Show: atalog

Habitable Zone: Weird Possibilities Tidally locked planets close to a star might behabitable (clouds bounce light off the top of theatmosphere and strong winds move heat around) Pulsar planets might survivewith thick atmospheres.Radiation from pulsar couldkeep them warm. Exomoons? Just starting to findmoons outside our solar system

Looking Closer: Biomarkers* *Water – naturally occurring but good sign*Oxygen – produced by life on Earth, but can be made without life*Oxygen methane – good sign & hard to do without life*Green – Earth is noticeably green in visible light thanks to plantsInfrared is a greatplace to look!Earth’s spectrum

Looking Closer: Biomarkers Good news: big molecules like H2O, CO2, CH4 make big signals Bad news:exoplanetsare far awayand hard toobserveGood news:we’re gettingbetter atobserving! James Webb SpaceTelescope will look forthese signals in exoplanetatmospheres!

Have aliens visited us? No evidence.How would they travel? Fast (impossible) Faster than light travel is impossibleas far as we knowAlmost-fast-as-light travel makesyour ship infinitely heavy (Einstein)We don’t know how wormholesworkSlow (very slow)Humans are prettysmart – and bad atkeeping secrets

Have aliens visited us? No evidence. Too costly in terms ofenergy Most UFO sightingsare not UFOs Ancient monumentsdo not point to aliensScience can’t prove anegative.BUTScience does start withthe simplest answer:No aliens have madecontact

But could aliens be out there?If we’re the only ones, that means there’s less than 1 in 10billion trillion chance of intelligent life forming.Watch/Show: universe/

The DrakeEquation:The equation is usedto estimate thenumber of likelycivilizations in theuniverseFrank Drake: Howlikely is it that weare alone?

The Drake Equation: Estimating theNumber of CivilizationsConservative numbers:R 1.5–3 yr 1, fp · ne · fl 10 5, fi 10 9, fc 0.2 and L 304 years 10 11Not goodOptimistic numbers:XR 1.5–3 yr 1, fp · ne · fl 0.026, fi 1, fc 0.2 and L 109 years 15,600,000A lot better!

The Fermi Paradox* Contradiction of the missing evidence of lifeoutside Earth & how common life should be* If life and intelligence are common, why haven’t weheard from aliens? In Fermi’s words: “Where is everybody?” An alien civilization could conquer a galaxy in a fewtens of millions of years. The universe is billions ofyears old.Watch (6:21): Where areall the aliens?https://www.youtube.com/watch?v sNhhvQGsMEcEnrico Fermi

The Fermi Paradox & many solutions*

The Fermi Paradox & many solutions*

The Fermi Paradoxhttps://xkcd.com/638/

Communications with Other CivilizationsSETI: Search for Extraterrestrial IntelligenceTo explore, understand and explain theorigin and nature of life in the universeand the evolution of intelligence Listening for radio waves is one ofmany areas of research*The Allen Telescope Array(only SETI), California- Listening for radio waveshttps://www.seti.org/ Optical SETI – lookingfor visible light* Possibly send out lasersignals?

Should humans be sending out signals? NASA’s Pioneer 10 & 11 NASA’s Voyager 1 & 2: Golden Record Messaging Extraterrestrial Intelligence (METI)sent a radio transmission from Tromsø, Norway Unintentional transmissions to the universe Laser pulses General radio noiseShow/Watch:SpacecraftLocations

Scientists Leading the WayJill Tarter led SETI for decades,making the Allen Array possibleSaraSeager atMIT islooking foranotherEarth

Slido.com Class Poll Enter code: #K261 Answer this: Do you think life exists outside of Earth now?

“The universe is apretty big place. Ifit's just us, seemslike an awful wasteof space.”― Carl Sagan

Be youLook upDream bigKeep learning

“The Universe is an unsettlingly bigplace, a fact which for the sake of a quietlife most people tend to ignore.” Douglas Adams, author of The Restaurant at the End ofthe Universe, Hitchhiker's Guide to the Galaxy Look Up: There is a big universe outthere. Be You: Recognize your place in the universe. There is no one else like you.

Big numbers,only 1 you! 2 trillion galaxies Each with at least 100 billion stars Each star with at least 1 planet There is only 1 planet that we knowofwhich holds life Over 7 billion people on Earth and only 1 you! Be You

Look up: Shift your perspective Be you: Share your skills, gifts & talents

“The more clearly we can focus our attentionon the wonders and realities of the universeabout us, the less taste we shall have fordestruction.”- Rachel Carson, scientist, nature lover &conservationist Keep Learning: Focus File:ISS-35 Parts of Mexico, California and Nevada (2).jpg

“The purpose of education is to stretch yourmind so that it never returns to its originalshape.” – Horace Mann, educator Keep learning: Stay curious

Keep Learning: Investigate faithCharles H. Townes Nobel Prize in Physics in 1964 for inventing the laser,physicist and astronomer“Science and religion are both efforts tounderstand the universe.Science seeks to understand how the universeworks and how humans work,while religion is an attempt to understandthe meaning and purpose of the universe and ofhumankind,which requires an understanding of theirworkings.”

Dream a crazy, big ut-600000-people-on-mars-within-100-years/

Be youLook upDream bigKeep learning

Want more astronomy? Join the Minnesota Astronomical Society:http://www.mnastro.org/ Space news websites: www.space.com www.astronomy.com www.skyandtelescope.com

Class Feedback for Raquel Notecard One side: What did you like about astronomyclass?Optionalwatch: side: What would you change Turnover,– Other Life in the Universe: Crash Course Astronomy #46or improveaboutclass? Ted Talk:Whereastronomyare all the Aliens?By Stephen Webb Name is optional When finished, place in big envelope

Homework & Updates Keep up with Study Points D2L Quiz 9-13 available; Quizzes 9-13 for Test 3 Optional – watch: Life in the Universe: Crash Course Astronomy #46 Ted Talk: Where are all the Aliens? By Stephen Webb Try out Grade Calculator on class website Tutor Oskar available in T bldg. room 3200 Observations: Astronomy News Evalution Due TODAY Dec. 10 (20 pts) Evaluate astro. news Sunset – Part 2 Due TODAY Dec. 10 (10 points) Take 2nd picture of sunset insame place Take picture about 4pm; sunsets about 4:30pm Stargazing Due Dec. 17 (20 pts) Go stargazing & write report Telescope Due Dec. 17 (20 pts) Look through a telescope Look at calendar options & weather Moon Craters Due Dec. 17 (10 pts) Look at magnified moon craters Borrow binoculars from Lab room Optional Lab Test 2 today, Dec. 10 or Thursday, Dec. 12

Calendar Summary Tuesday, 12/10: Life in the Universe (optional Lab Test 2) Thursday, 12/12: Test 3 (60 multiple choice questions) Based on last 8 lectures & 5 D2L quizzes 9-13Some questions from D2L quizzesBring pencil, no calculator neededOptional Lab Test 2 during lab time Based on all 23 lectures & 13 D2L quizzes (the whole semester)Many questions from D2L quizzesBring pencil & calculator if you have one (some in classroom for you)Remember lowest of 4 tests is dropped (Test 1, 2, 3, & Final).If you took 3 previous tests and are happy with your grade, then youdon’t have to take the Final Test. If you missed a previous test, youmust take the Final Test. If you are trying to increase your grade, takethe final to hopefully drop a different test. No Astronomy on 12/19. Tuesday, 12/17: Final Test today & handback Test 3

The Copernican Principle* Earth is not a privileged/special place in the universe* Not the center of the solar system Not the center of the universe Not the only planet Many stars like our Sun From Galileo to Hubble, science proves the universe is much bigger than us So why should we be the only planet with life?