chapter 1 a universe of life? - santa monica...
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8/29/2010
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Chapter 1
A Universe of Life?
Why Study the Universe?
Are we alone? Aliens are everywhere in the movies!
The Day the Earth Stood Still
(1951)
ET: The Extra-Terrestrial
(1982)
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Star Trek (1966-1969)
Alien (1979)
Mars Attacks!(1996)
Common Link?
Common Link?
All are humanoid!
Anthropocentrism
However, extraterrestrial Life may not look like us at all!
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How then will we recognize it?Need to identify the
fundamental characteristics that any kind of Life will
possess
Astrobiology
The study of life in the Universe
Goals of Astrobiology
1. Understanding of the conditions required for life on
Earth
2. The search for life elsewhere in the solar
system
3. The search for life beyond the solar system
Astrobiology is an integrated science
The Role of Astronomy
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Ancient View
The Geocentric Universe
We occupy a special place at the center of the Universe! Modern View
The Earth is just one of 8 planets in our solar system…
Our Sun is just one of roughly a 100 billion stars in our Milky Way Galaxy!
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Our galaxy is just of 100’s of billions of galaxies in our Universe!
How many stars in the Universe?
Try counting every grain of sand on the Earth’s surface!
Lessons from Modern Astronomy
1. The Universe is very large and old
2. The building blocks of life are common
3. The laws of physics are universal
Conclusion?
We are not special!
The universe most likely contains many stars and
planets similar to the earth and Sun
The Role of Planetary Science
Planet Formation
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Extrasolar Planets
Comparative Planetology
Habitable Planets
Those capable of sustaining life
Does not necessarily mean that life is present!
The Role of Biology
The laws of physics and chemistry are the same
everywhere!
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Simple life appeared rapidly but complex life took billions of years to develop on Earth
The most likely type of Extraterrestrial Life!
Searching for life in the Universe
Earth!
Conclusions from studying life on Earth
3 Basic Requirements for Chemically-based Life
1. Atoms to make biological molecules
2. A liquid solvent
3. A source of energy
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3 most likely places to find life in the solar system
Mars
Jupiter’sMoonEuropa
Saturn’s MoonEnceladus
Why?All have or have had liquid water on or beneath their
surfaces!
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