1. Describe the three main methods used to find exoplanets.
2. What is a “Hot Jupiter?”
- Large planets orbiting at extremely close distances to the parent star.
3. What is the main problem with the current methods used to find exoplanets?
- We cannot find rocky, Earth-like exoplanets using the current methods.
4. Why is this?
- Because of atmospheric turbulence.
- Small mass so smaller effect on host star.
5. What is the Kepler Spacecraft?
- NASA space observatory
- Aims to discover earth sized planets in habitable zone
- Only instrument is photometer (measures variations in light as planets pass in front of their host star).
- Transit method
6. What are the problems of using this method?
- We must be in the plane of the exoplanet’s ecliptic to detect changes in light.
7. What are the two essential chemical ingredients for life?
- Has the ability to make interesting compounds
- Organic molecules
- “Building blocks” of life
- Liquid water
- Transport Medium
- Essential for Photosynthesis
- Essential for Hydrolysis
- Break down of molecules
8. Where is water on Earth thought to have come from?
- Deposited by ice containing comets striking Earth.
- Out-gassing of Hydrogen and Oxygen from volcanoes.
9. How do we plan to determine if it is likely that substantial amounts of water were delivered to Earth by comets?
- ESA Rosetta
- Launched 2004
- Heading for comet 67p (Churyumov- Cerasimenco)
- Ptolemy (one of its instruments)
- Analyse water content
- Check to see what Isotopes are present (are they similar to Isotopes in Earth water?)
10. What is the habitable zone?
- Narrow range of distances from star
- Temperature allows liquid water to exist
- Goldilocks Zone (neither to hot or to cold)
11. Draw a graph to describe how the mass of a star affects the habitable zone.
12. Who was Drake?
13. What is the Drake Equation?
- The estimated probability of life existing elsewhere in our Galaxy.
- Also known as Green Bank equation.
- N = R* fp ne fl fi fc L
14. List some of the factors considered in the Drake Equation.
- Number of stars in our galaxy
- Fraction of stars with planetary systems
- Number of planets capable of sustaining life
- Fraction of life forms that are intelligent
- Fraction of these that can and wish to communicate
- Fraction of planet’s lifetime of which such civilisations can live.
15. Where else in our solar system is life most likely?
- Europa (one of Jupiter’s moons)
16. Name 3 techniques astronomers use to search for signs of life on other planets.
- Space probes
- Viking/Curiosity and Mars
- Huygens and Titan (Saturn’s largest moon)
- Spectral analysis of planetary atmospheres of rocky planets.
- Looking for oxygen, methane etc.
- Analysis of radio waves.
- Intelligent communications.
17. Name 2 potential dangers of finding extra-terrestrial life.