Astro 120: Spring 2016
Spring 2016 Review Sheet
Review Sheet 3
Exam 3 is Monda, May 2 2016 9:45-11:45
The final exam is partly comprehensive - about half of the exam will
cover material since Exam 2, and half from the main concepts from the first two parts of the course.
Be sure review the eariler material as well as that on
Impacts, the Sun, Solar System History, and Life in the Universe
Astrology and Pseudoscience
- Fundamental ideas of astrology.
- Requirement for new unknown force.
- Testing astrology in a fair and rigorous way.
- Results of in-class experimet with sun-sign astrology.
- Results of more stringent experiments.
- Themes of pseudoscience; examples and how to tell
pseudoscience from objective science.
- impact record of the Moon compared with the inner planets
- terrestrial impacts.
- the impact hazard scale: small impacts are more frequent
- crater size related to impactor size (crater 10x larger than
- effects of large impacts on life on Earth
- extinction of the dinosaurs: evidence of an impact causing it
- other sample impacts: Arizona meteor crater, Tunguska,
Comet SL9 and Jupiter, Chelyabinsk impact in Russia.
- Observed parameters of the Sun: temperature, size, luminosity.
- The solar photosphere, chromosphere and corona.
- Granulation, sunspots, prominences, flares.
- Sunspots, magnetic fields and the 22 year sunspot cycle.
- Energy generation in the Sun via nuclear fusion.
Formation of the solar system
- Collapse of the sun and solar system out of a molecular cloud.
- Gravitational collapse
- formation of a disk.
- Formation of planets in the solar nebula via
- planetessimal formation
- Temperature distribution in the solar nebula
- The'frost line' and formation of icy vs. rocky planets
- Time scale for planet formation was short (<<100 million years)
compared with the age of the solar system.
Other Solar Systems
- Observational challenge of finding planets around other stars
- Planet detection methods based on 'wobbling' of stars under gravitational
influence of surrounding planets.
- The radial velocity technique and the first discoveries.
- The transit technique as the most prolific.
- Discoveries over the past 20 years of > 1000 planetary systems
- the 'Hot Jupiter' issue
- Questions arising from these discoveries (i.e. is our solar system typical?)
- Searching for other Earth-like planets - The Kepler Mission
Life in the Universe
- The probability of life on other planets - assumptions and guesses.
- Drake's estimator of the probability of finding a technological
civilization in the galaxy.
- Astronomical, biological, and sociologicaly factors.
- The habitable zone - liquid water and the development of life.
- Likely values for each factor in the Drake Equation.
- Which terms in the Drake "equation" are more certain, which are not.
- The Search for Extra-Terrestrial Intellegence (SETI).
- Methods used by SETI in the search for artificial signals from space.
- Why radio waves are a good way of transmitting signals across the
- Current searches and results.
- Future prospects