Unit 2 Exoplanets Flashcards
When was the first exoplanet discovered?
- Since then several hundred planetary systems have been discovered as technology improves.
Which three methods can be used to detect exoplanets?
Astrometry: As massive exoplanets orbit their parent star their gravitational pull can be strong enough to cause the star to move/wobble.
Transit Method: When an exoplanet moves across the disc of it’s host star it can cause a very small drop in brightness (about 1%).
Radial Velocity:When an exoplanet transits across the star it can cause small red-shifts and blue-shifts, then spectroscopy can reveal the small shifts in wavelenght.
What can current methods of detecting exoplanets not detect?
Small rocky planets. They can only detect planets like Jupiter.
What are the two essential chemicals for life?
Carbon.
Liquid water.
Water on Earth is thought to have two principal origins. What are they?
Outgassing of hydrogen and oxygen from volcanos to that combined to create steam.
Deposition by comets containing ice.
In order for life to develop the planet must life the the …………… zone.
Habitable Zone or Goldilocks Zone where its not to hot and not to cold.
What is the Drake Equation?
The Drake Equation is the (gu)estimated equation that predicts the chance of intelligent life in our galaxy.
Give examples of factors in the Drake Equation.
Eg: Fraction of Earth like planets per planetary system.
Number of stars in our galaxy
Number of planets capable of sustaining life.
Number of life-forms that are intelligent.
Places in the Solar System where life may exist.
Eg: Mars
Europa
Titan
What techniques can astronomers use to search for signs of life?
Eg: Space probes that search directly for microbes or their bi-products.
Spectral analysis of a planet and it’s atmosphere.
Analysis of radio waves fro extra-terrestrial signals.
