about exoplanets

1. BY: STELLA RANCE

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

7. Planet Habitability
• Potential of a planet to develop and sustain life.
• Largely agreed on an extrapolation of Earth’s and
Sun’s characteristics.
• HZ: Habitable zone.
NASA
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.
Transit of Venus (2012)

15. 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.

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

17. 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.