2. Index
• Introduction
• History
• ‘Types’ of exoplanets
• Purpose?
• Planet Habitability
• Goldilock’s zone
• Atmosphere
• Chemical environment
• Spectograph
• Energy required for metabolism
• Drake’s equation
• Video
• What is the importance of exoplanets?
• Conclusion

3. INTRODUCTION
• An exoplanet is a planet that orbit a different star from the
sun
• More than 1800 exoplanets have been discovered
• Alpha Centuiri Bb nearest planet?
• Almost all of the planets detected so far are within the Milky
Way.
• DENIS-P J082303.1-491201 b, about 29 times the mass
of Jupiter

4. HISTORY
• At first scientist supposed that
existed but they couldn’t prove it
• In the 16th century Giordano
Bruno put foward the view that
the other stars should have also
planets like the sun
• The first confirmed detection
came in 1992

5. ``TYPES´´ OF EXOPLANETS
• The classification of exoplanet types is unfortunately arbitrary
• Terrestrial Planet
Solar System Planets in the Name
Size Prefixes
Hot and Cold terms

6. PURPOSE?
Why do we spent our
money in something that
is thousands of millions
of kilometres away?
Although I could find more reasons, I think the best reason is,
because we simply can!

7. Planet Habitability
• Potential of a planet to develop and sustain life.
• Largely agreed on an extrapolation of Earth’s and
Sun’s characteristics.
NASA
• HZ: Habitable zone.
Extended regions of water.
Favourable conditions for the assembly of
complex organic molecules.
Energy sources.

8. Goldilock’s zone
• Shell-shaped region of space surronding a star.
• Liquid water can appear.
• Location depends on the energy the star is
outputting (inverse squared law).
• Where temperature of the planet goes from 0-
100ºC.

9. Atmosphere
 Protecting the planet an inhabitans from
radiation.
 Keep planet surface warm.
 Provide the planet with oxygen so life evolves.
• Contain some of the chemical elements
necessary for life.

10. Chemical Enviroment
• Essential chemical elements.
• Water: Liquid, able to have pH.
• Primary focus of astrobiological research.

11. Spectograph.
• Light reacts differently for
each element.
• Depending on the peak on
the spectograph, we can
tell which element it is
about.
• Valid for the atmosphere
and the elements forming
the surface.

12. Energy required for metabolsim.
• Solar: reaching
the surface and
near surface.
Perfect star: Stable
variability and
high metallicity.
• Geothermal:
Subsurface.

13. Drake’s Equation
 N* is the number of total stars in the Milky Way
 fp is the fraction of those stars that have planets
 ne is the number of planets per star that could be capable of sustaining
life.
 fl is the estimation of life actually evolving on the planets on which it is
capable to.
 fi is the estimation of intelligent life evolving.
 fc is the fraction of that intelligent life that would be capable of
communication.
 fL is the fraction of the life of the planet during which this civilization could
live.
BBC: Drake´s equation.

14. VIDEO
• Direct discovery: nearby stars+ very large planets.
• The majority have been discovered through
indirect methods.
• 1. A planet passing in front of a star will make it
darker: the amount of darkness determines the
size of the panet.

15. Transit of Venus (2012)

16. 2. The center of mass is
not at the centre of the
star, which creates a tiny
wobble in the velocity of
the star.
Discovery of more than
1800 exoplanets as of
2014.

17. •
What is the importance of
exoplanets?
- What is the point in studying
them?
-Is it worth the expense of money
in it?

18. Conclusion
• An exoplanet is a planet that orbits a different
star from the Sun.
• The first confirmed detection was in 1992.
• An exoplanet habitability depends on the
following requirements: Extended regions of
water, good conditions for the assembly of
complex molecular particles and energy sources.
• They can be discovered by direct or indirect
methods.