ASTR 1050 Exam 2 Study Guide

These are the course topics addressed on Exam 2.

Standard 7.  Identify and describe the different categories of signals that Earthbound observers receive from space.

• Electromagnetic radiation (photons)
• What are the others?

Standard 8.  Relate the energy of electromagnetic radiation with wavelength and frequency, and order the spectral regions.

• Relation E = hf
• Order of Visible, IR, UV, microwave, radio, X-ray, γ ray
• Relationship of wave speed c to wavelength and period, wavelength and frequency
• Relationship of wave frequency to period

Standard 9.  Describe the characteristics of black body radiation and what conditions affect it.

• How the power output changes with temperature
• How the power output depends on surface area
• General shape of the graph of intensity vs. wavelength
• How the wavelength of maximum emission changes with temperature

Standard 10.  Compare and evaluate the advantages and disadvantages of refracting and reflecting telescopes.

• Light path
• Chromatic aberration
• Instrumental stability
• Meeting specifications

Standard 11.  Identify and explain the observational challenges with different bands of the electromagnetic spectrum.

• Which bands are absorbed by the atmosphere
• How resolution depends on wavelength
• Which bands don’t reflect well, and how to accommodate that

Standard 12.  Match the type of a spectrum to the substance and conditions that create it.  Describe the effect on a spectrum of movement of the source toward or away from the detector.

• Kirchhoff’s spectroscopy rules (continuous, absorption line, emission line)
• Doppler shift

Standard 13.  Explain what a Jeans instability is, what triggers one, and how one evolves.

• Pressure vs. gravity: hydrostatic equilibrium
• How temperature affects pressure
• The role of dust in gravitational collapse
• Triggering events: stellar outburst, nebular collisions, …

Standard 14.  Identify and describe the principal categories of Solar System objects.

• Large objects, small objects
• Locations, compositions, and orbital properties of objects
• Overlapping categories: many objects match multiple categories
• Objects characterized by composition and orbit

Standard 15.  Describe at least five ways in which Earth differs from other rocky planets.

• Characteristics like overall composition, size, atmospheric characteristics, surface composition, surface processes, surface features, geologic activity, magnetic field

Standard 16.  Describe and explain the interaction of Earth with the Moon’s orbit.

• What “tidal forces” are and how they work
• How tidal forces affect the Moon’s orbit
• How tidal forces affect the Moon’s spin
• How tidal forces affect the Earth’s spin

Standard 17.  Describe major features of the Moon’s surface.

• Names and descriptions of light and dark areas
• Features of light and dark areas
• Material composition of light and dark areas
• Comparative ages of light and dark areas, and evidence

Standard 18.  Identify and explain evidence for the Giant Impact hypothesis of the Moon’s formation.

• What does the Giant Impact hypothesis entail?
• What are other possibilities for the Moon’s formation, and what evidence discredits them?
• Why is the Giant Impact hypothesis the best explanation for observations?

Standard 19.  Identify the unique aspects of Mercury’s composition.

• Similarities and differences to other rocky planets
• (I should have included something about Mercury’s orbit and spin)

Standard 20.  Describe the composition and effects of Venus’s atmosphere.

• Composition
• Surface pressure
• Clouds
• Effect on surface

Standard 21.  Describe the composition and characteristics of Venus’s surface.

• What do we know about Venus’s surface, and how do we know it?
• What are the major topological features of Venus’s surface?
• What geologic processes have affected Venus?
• Is Venus geologically active?
• (I should have included something about Venus’s orbit and spin)

Standard 22.  Identify evidence that Mars once contained abundant surface water.

• Topological features
• Meteorite evidence
• Surface mineralogy
• Stratigraphy