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Name____________________________________________
Name____________________________________________

... 3. What is a galaxy? A huge group of single stars, star systems, star clusters, dust, and gas bound together by gravity. 4. What does an elliptical galaxy look like? Round or flattened ball; smashed circle 5. The Milky Way Galaxy is just one of billions of galaxies in the universe. 6. Our Solar Syst ...
AST101_lect_18
AST101_lect_18

... •Fp: Fraction of stars with planets •Nh: number of habitable planets per star •Fl: fraction of habitable planets on which life evolves •Fi: fraction of cases where intelligent life develops •Fc: fraction of intelligent life that develops technological civilizations •L: lifetimes of a technological c ...
Pluto
Pluto

... • It is the area in the galaxy whose boundaries are set by its calm and safe environment, and access to the chemical materials necessary for building terrestrial planets similar to the Earth. ...
Homework, November 16, 2006 AST110-6
Homework, November 16, 2006 AST110-6

... how many stars have Earth-like planets, nor do we know the likelihood that such planets might harbor advanced civilizations like our own. However, some stars can probably be ruled out as candidates for advanced civilizations. For example, given that it took a few billion years for humans to evolve o ...
Project topics
Project topics

... 1. Equipment and instruments that explore the universe (telescopes, satellites, probes, rockets, shuttles etc.). 2. Electromagnetic spectrum and its importance in astronomy. 3. Spectroscopes and the spectrums of stars. Include information about a spectroscope, spectrums of different gases, the Doppl ...
Document
Document

... Assuming that all intelligent civilations are made of things that we would consider living, we can re-work the Drake Equation to estimate the number of opportunities for life (intelligent or not): Nlife = R* x fp x ne x fl x L where N = number of civilizations that might possibly communicate with us ...
Explorations of the Universe
Explorations of the Universe

... x Fraction of Stars with Planets (1/4?) x Number of suitable planets per star (2?) x Fraction of planets where life appears (1/2??) x Fraction of planets with intelligence (???) x Fraction of planets with technology (???) x Fraction of planet’s life with technology (???) ...
ASTR-1020: Astronomy II Course Lecture Notes - Faculty
ASTR-1020: Astronomy II Course Lecture Notes - Faculty

... 4. We are closer to answering this question of whether or not we are alone in the Universe than we ever have been throughout history. Humans seem to fear loneliness, so this question is very important to many people. Hopefully, with the aid of our current technology, we will discover the evidence of ...
Maybe We Are Alone in the Universe, After All
Maybe We Are Alone in the Universe, After All

... Date of Publication: February 8, 2000 Website: The New York Times Web Address: http://www.nytimes.com/2000/02/08/science/maybe-we-are-alone-in-the-universeafter-all.html?pagewanted=all&src=pm Date of Access: February 10, 2013 In the last few decades, a growing number of astronomers have promulgated ...
What is life?
What is life?

... Requirements for Life in Other Planetary Systems • Planetary systems are probably common. • Stable orbit around the star  consider only single stars. • Time for evolution  consider only F5 or less massive stars. • Moderate temperatures  Life zone around the star ...
Implications of the Search and Discovery
Implications of the Search and Discovery

... x Fraction of Stars with Planets (1/4?) x Number of suitable planets per star (2?) x Fraction of planets where life appears (1/2??) x Fraction of planets with intelligence (???) x Fraction of planets with technology (???) x Fraction of planet’s life with technology (???) ...
Implications of the Search and Discovery of Life in the Universe
Implications of the Search and Discovery of Life in the Universe

... x Fraction of Stars with Planets (1/4?) x Number of suitable planets per star (2?) x Fraction of planets where life appears (1/2??) x Fraction of planets with intelligence (???) x Fraction of planets with technology (???) x Fraction of planet’s life with technology (???) ...
Astrobio
Astrobio

... Astrobiology: the origin, evolution, distribution, and future of life in the universe Outline of this class: Life, extreme life on earth Where else in solar system could life exist? Mars, Titan& Europa, Habitable zone (review), difficulty with estimating probability of life, Drake equation for estim ...
Study Guide_galaxies, Tools, and Stars Test
Study Guide_galaxies, Tools, and Stars Test

... 6. Name and describe the 3 types of galaxies. 7. Where is our solar system located in the Milky Way galaxy? 8. What is a light year? 9. What contains all the matter and energy that exists? 10. Name two types of optical telescopes. 11. What do radio telescopes receive and where do they come from? 12. ...
Chapter 1: A Universe of Life
Chapter 1: A Universe of Life

... 23. The Search for Extraterrestrial Intelligence (SETI) program currently involves A) broadcasting signals for other advanced civilizations to receive B) listening for signals broadcast by advanced civilizations C) searching for life on planets around other stars D) searching for life in our solar s ...
Study Guide for Quiz on Astronomy: The Moon, Sun
Study Guide for Quiz on Astronomy: The Moon, Sun

... 4. Is a light-year a unit of time? Explain. ______________Why?____________________________. 5. At what point in the evolution of a star is the star actually born? 6. What is Hubble’s law? 7. The most common chemical element in a star is? ___________________ 8. If a star dies and explodes, it becomes ...
Life in the Universe
Life in the Universe

... There are social complications of time dilation. ...
Life in Space & Drake`s Equation
Life in Space & Drake`s Equation

... There are social complications of time dilation. ...
Are we Alone? The Search for Life Beyond the
Are we Alone? The Search for Life Beyond the

... We could detect evidence of life by observing the spectra of the planet’s atmosphere. ...
24. Life Beyond Earth: Prospects for Microbes, Civilizations, and
24. Life Beyond Earth: Prospects for Microbes, Civilizations, and

... • Assuming, like us, most civilizations take 5 billion yrs to arise. • the Galaxy is 10 billion yrs old, 5 billion yrs older than Earth • IF there are other civilizations, the first could have arisen as early as 5 billion yrs ago • there should be many civilizations which are millions or billions of ...
34_alone
34_alone

... • How could the Universe be so big and so so lonely? • What is our destiny? If we kill ourselves, what has it all been for? • All those worlds we can not detect. What are they for? • “It would be a great waste of space”. ...
pptx
pptx

... travel through the entire Milky Way. They also require the least energy to transmit because they have low energy. The atmosphere is transparent to radio waves. As a result, we can easily receive radio signals from space, and our transmissions escape into space as well. ...
F p = Fraction of good stars with planets
F p = Fraction of good stars with planets

... Saturn’s Titan: Cassini / Huygens Mission Cassini still orbiting Saturn, Huygens probe landed on its moon, Titan a few years ago. ...
Geller Slides on Contact with ET
Geller Slides on Contact with ET

... x Fraction of planets where life appears (1/2??) x Fraction of planets with intelligence (???) x Fraction of planets with technology (???) x Fraction of planet’s life with technology (???) ...
Lecture 34 – Exobiology- Life Elsewhere in the Universe
Lecture 34 – Exobiology- Life Elsewhere in the Universe

... On Earth, it took 4 billion years from formation to the appearance of complex, multicellular life (“Cambrian Explosion”). This requires the star to remain relatively constant for a very long time. ...
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Fermi paradox



The Fermi paradox (or Fermi's paradox) is the apparent contradiction between high estimates of the probability of the existence of extraterrestrial civilizations, such as in the Drake equation, and the lack of evidence for such civilizations. The basic points of the argument, made by physicists Enrico Fermi and Michael H. Hart, are: The Sun is a typical star, and there are billions of stars in the galaxy that are billions of years older. With high probability, some of these stars will have Earth-like planets, and if the earth is typical, some might develop intelligent life. Some of these civilizations might develop interstellar travel, a step the Earth is investigating now. Even at the slow pace of currently envisioned interstellar travel, the Milky Way galaxy could be completely traversed in about a million years.According to this line of thinking, the Earth should already have been visited by extraterrestrial aliens though Fermi saw no convincing evidence of this, nor any signs of alien intelligence anywhere in the observable universe, leading him to ask, ""Where is everybody?""
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