Chapter 5 — Light: The Cosmic Messenger
Spectrum — all the waves (EM range).
Wavelength — crest to crest.
Frequency — Hz; beats per second.
Speed of light — 300,000 km/s.
Photons — duality (particle or wave).
Types of light:
- Gamma — most powerful, shortest wavelength.
- X-ray — 1–20 nm.
- UV — sunburn.
- Visible — 400–700 nm.
- IR — heat.
- Radio — longest wave, least powerful.
Atom:
- Protons — positive particles.
- Neutrons — no charge.
- Electrons — negative particle.
Atomic Number — number of protons.
Isotopes — same protons, different neutrons.
Molecules — several atoms.
Types of spectrum:
- Thermal (emission) — just certain colors = hot gas.
- Absorption — cool gas, all colors with some missing.
- Continuous — all colors (solid / hot dense).
Ions — extra electron or missing one.
Doppler effect — motion towards or away.
Red vs. blue — red = away; blue = toward.
Angular resolution — ability to see details.
Refracting vs. reflecting — know the diagrams (refractor = lens, reflector = mirror).
Adaptive optics — helps with seeing (compensates atmospheric turbulence).
Interferometer — using several telescopes together.
Chapter 6 — Formation of the Solar System
Terrestrials vs. Jovians — know differences (rocky-small-close vs. gaseous-large-far).
Hydrogen compounds — common on Jovians (H₂O, NH₃, CH₄).
Asteroids — rocks between Mars and Jupiter.
Comets — ice; leftovers from formation.
Nebular theory — gas cloud forming the solar system.
Accretion — bodies hitting each other and growing.
Planetesimals — bump into each other to form.
Protoplanets — grow by gravity.
Radiometric dating — method to date materials (oldest meteorites = 4.55 Gyr).
Chapter 7 — Earth and the Terrestrial Worlds
Earth
Earth cross section — know it (crust, mantle, outer core, inner core).
Lithosphere — brittle upper crust.
Differentiation — Earth is layered (the most differentiated terrestrial).
Convection — heat transfer by currents.
Magnetic field — generated by convection.
P vs S waves — P primary (fastest); S secondary (will not move through liquid).
Aurora — Sun's wind hits upper atmosphere.
Magnetosphere — Van Allen belts surround Earth.
Earth shapers: impacts · volcanoes · tectonics · erosion.
Ozone — O₃, created by UV in stratosphere.
Greenhouse effect — warming by atmosphere.
Greenhouse gases — main are water vapor and carbon dioxide.
Moon
Size — 1/4 size of Earth.
Maria — dark, old impacts; mascons.
Highlands — oldest white crust.
Origins ideas (Ch 6) — giant impact hypothesis.
Mercury
Size — 1/3 Earth.
Rotation — 59 days.
Revolution — 88 days.
Temperature — 900 °F.
Caloris Basin — largest impact in the solar system.
Scarp — cliffs formed by Mercury shrinking.
Venus
Size — same as Earth.
Rotation — 243 days, backward (retrograde).
Revolution — 225 days.
Temperature — 900 °F (by greenhouse effect).
Atmosphere — 90 times thicker than Earth; 96% CO₂.
Clouds — thick, sulfuric acid.
Mars
Size — 1/2 Earth.
Rotation — 24 h 30 min.
Revolution — 23 months (≈ 2 years).
Atmosphere — 1% of Earth's, CO₂.
Channels — once flowing rivers.
Permafrost — at poles, maybe over whole planet; water frozen.
Study workflow
Drill these terms in Flashcards (filter by U2 tags) → take Practice Exam → review Cheat Sheet → take Test 2.