Test 2 Review Outline

1. Test 2 Review Outline

2. Summary of Chapter 3 • Refracting telescopes make images with a lens. • Reflecting telescopes make images with a mirror. • Modern research telescopes are all reflectors. • CCDs are used for data collection. • Data can be formed into image, analyzed spectroscopically, or used to measure intensity. • Large telescopes gather much more light, allowing study of very faint sources. • Large telescopes also have better resolution.

3. Summary of Chapter 3, cont. • Resolution of ground-based optical telescopes is limited by atmospheric effects. • Resolution of radio or space-based telescopes is limited by diffraction. • Active and adaptive optics can minimize atmospheric effects. • Radio telescopes need large collection area; diffraction is limited. • Interferometry can greatly improve resolution.

4. Summary of Chapter 3, cont. • Infrared and ultraviolet telescopes are similar to optical. • Ultraviolet telescopes must be above atmosphere. • X rays can be focused, but very differently than visible light. • Gamma rays can be detected but not imaged.

5. Summary of Chapter 4 • Solar system consists of Sun and everything orbiting it. • Asteroids are rocky, and most orbit between orbits of Mars and Jupiter. • Comets are icy, and are believed to have formed early in the solar system’s life. • Major planets orbit Sun in same sense, and all but Venus rotate in that sense as well. • Planetary orbits lie almost in the same plane.

6. Summary of Chapter 4, cont. • Four inner planets – terrestrial planets – are rocky, small, and dense. • Four outer planets – Jovian planets – are gaseous and large. • Nebular theory of solar system formation: Cloud of gas and dust gradually collapsed under its own gravity, spinning faster as it shrank. • Condensation theory says dust grains acted as condensation nuclei, beginning formation of larger objects.

7. Summary of Chapter 4, cont. • Planets have been discovered in other solar systems. • Most are large and orbit much closer to the Sun than the large planets in our solar system do.

8. Summary of Chapter 5 • Earth’s structure, from inside out: Core, mantle, crust, hydrosphere, atmosphere, magnetosphere • Tides are caused by gravitational effects of Moon and Sun. • Atmosphere is mostly nitrogen and oxygen; thins rapidly with increasing altitude. • Greenhouse effect keeps Earth warmer than it would otherwise be.

9. Summary of Chapter 5, cont. • Can study interior by studying seismic waves. • Crust is made of plates that move independently. • Movement at plate boundaries can cause earthquakes, volcanic activity, mountain ranges, and rifts. • New crust formed at rifts shows evidence of magnetic field reversals. • Earth’s magnetic field traps charged particles from solar wind.

10. Summary of Chapter 5, cont. • Main surface features on Moon: maria, highlands • Heavily cratered • No atmosphere and large day–night temperature excursions • Tidal interactions responsible for synchronicity of Moon’s orbit

11. Summary of Chapter 5, cont. • The Moon’s surface has both rocky and dusty material. • There is evidence for volcanic activity. • The Moon apparently formed as a result of a large object colliding with Earth.

12. Summary of Chapter 6 • Mercury is tidally locked in a 3:2 ratio with the Sun. • Mercury has no atmosphere; Venus has a very dense atmosphere, whereas the atmosphere of Mars is similar to Earth in composition but very thin. • Mercury has no maria, but does have extensive intercrater plains and scarps.

13. Summary of Chapter 6, cont. • Venus is never too far from the Sun, and is the brightest object in the sky (after the Sun and Moon). • It has many lava domes and shield volcanoes. • Venus is comparable to Earth in mass and radius. • Large amount of carbon dioxide in atmosphere, and closeness to the Sun, led to runaway greenhouse effect and very hot surface.

14. Summary of Chapter 6, cont. • Northern and southern hemispheres of Mars are very different. • South is higher and heavily cratered. • North is lower and relatively flat. • Major features: Tharsis bulge, Olympus Mons, Valles Marineris • Strong evidence for water on Mars in the past

15. Summary of Chapter 6, cont. • Mercury has very weak, remnant magnetic field. • Venus has none, probably because of very slow rotation. • Neither Venus nor Mars show signs of substantial tectonic activity.

16. Summary of Chapter 7 • Jupiter and Saturn were known to the ancients; Uranus was discovered by chance, and Neptune was predicted from anomalies in the orbit of Uranus. • Jovian planets are large but not dense; they are fluid and display differential rotation. • Cloud layers have light zones and dark bands; wind pattern, called zonal flow, is stable.

17. Summary of Chapter 7, cont. • Storms appear with regularity; the Great Red Spot of Jupiter has lasted for hundreds of years (that we know of). • Due to conductive interiors and rapid rotation, Jovian planets have large magnetic fields. • Jupiter, Saturn, and Neptune radiate more energy than they receive from the Sun.

18. Summary of Chapter 8 • Outer solar system has 6 large moons, 12 medium ones, and many smaller ones. • Titan has a thick atmosphere and may have flowing rivers of methane. • Triton has a fractured surface and a retrograde orbit. • Medium-sized moons of Saturn and Uranus are mostly rock and water ice. • Saturn’s rings are complex, and some are defined by shepherd moons.

19. Summary of Chapter 8, cont. • The Roche limit is the closest a moon can survive near a planet; inside this limit rings form instead. • Jupiter, Uranus, and Neptune all have faint ring systems. • Pluto has three moons, Charon, Nix, and Hydra. • Dwarf planets beyond Neptune (including Pluto) are now known as plutoids.