Transcript 1.Possibility of intelligent life outside of earth (cont.)

Search for Intelligent Life
Search for Intelligent Life
1. Possibility of intelligent life outside of earthDrake Equation- An early Approach to solving the
statistical problem of determining how many
advanced civilizations are out in space.
*** The mere presence of human indicates that this
number can not be ZERO!!!
1.Possibility of intelligent life outside of earth (cont.)
Drake Equation
Number of Technological, intelligent civilizations now present in the
universe =
A. Rate of star Formation averaged over the life time of a galaxy
B. Fraction of stars having planets
C. Average number of habitable planets within those planetary systems
D. Fraction of those planets on which life arises
E. Fraction of those life bearing planets on which intelligent life evolves
F. Fraction of those intelligent life planets that develop a technological
society
G. Average lifetime of a technologically competent society
A-100 billion stars over 10 billion years gives us an average of about 10
stars a year- Probably not too far of form actual value
B-F are up too speculation and become even harder to predict as we go
towards F.
Habitable zones of Different Types of Stars
2. Searching for Life
- The most likely source of finding Extra terrestrial
Intelligent life is by listening for them.
- SETI (Search for Extra Terrestrial Intelligence)
Privately funded search for E.T.
US Government also listens for any type of Radio wave coming from a particular
part of the sky that shows a pattern.
- Radio waves are used because other frequencies of Electromagnetic
Radiation (UV light, Visible Light, etc) are heavily scattered as it moves through
space
- The Earth now emits more radio waves then the Sun
- PROBLEM: Even light travels too slowly to have any hopes
of communicating with our nearest neighbors
Ex. Average distance between stars in our galaxy is about 100 light years.
So it would take 200 years to have a conversation with a CLOSE neighbor
2. Searching for Life
Visiting other Worlds???
Our Fastest Probe travels at the speed of 50 Km/s
at this pace the nearest star (Alpha Centuri) would take 50,000 years
to get to.
- Some of our Earliest Probes (Pioneer 10, Voyager
1+2) are just now leaving the Solar system and
they were launched almost 30 years ago
-
Is it Even a good idea to establish direct contact with Extra Terrestrials
if it is made possible???
Earth’s Radio Signals From Space
Large
Radio
TelescopeOne of
Many used
in SETI
Project
Pioneer 10 Gold Plaque (Similar to Voyager Plaque’s)