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exoplanetsstellarance.pdf
- 1.
- 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 exoplanetis 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 firstscientist 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 couldfind 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 • Potentialof 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-shapedregion 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 theplanet 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 • Essentialchemical elements. • Water: Liquid, able to have pH. • Primary focus of astrobiological research.
- 11. Spectograph. • Light reactsdifferently 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 formetabolsim. • 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 centerof 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 theimportance of exoplanets? - What is the point in studying them? -Is it worth the expense of money in it?
- 17. Conclusion • An exoplanetis 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.