Orbits
100 - The force responsible for the attraction of the Sun and planets.  (Gravity)
200 - The shape of a planet's orbit about the Sun.  (Ellipse)
300 - The fastest-moving planet in the Solar System.  (Mercury)
400 - The place in Earth's orbit when it is moving the fastest.  (Perihelion)
500 - An asteroid with a distance of 4 AU from the Sun would orbit in this many years.  (8)

Spectra
100 - "Electromagnetic radiation" is a fancy way of saying this common term.  (Light)
200 - Earth's surface gives off radiation mostly in this region of the spectrum.   (Infrared)
300 - The type of spectrum emitted by a solid object heated to some temperature.  (Blackbody)
400 - The type of spectrum emitted by the ion tail of a comet.  (Emission line)
500 - The property of a continuum spectrum that allows us to determine its temperature.  (Wavelength of peak)

Plate tectonics, earthquakes, volcanoes
100 - This is the only planet or moon in the solar system with plate tectonics.  (Earth)
200 - The name of the fault that passes through Berkeley.  (Hayward fault)  
300 - The youngest surface in the solar system belongs to this moon of Jupiter.  (Io)
400 - This type of igneous rock is created by lava that cools after reaching Earth's surface.  (Basalt)
500 - The process of one plate being driven beneath another at a boundary where two plates come together.  (Subduction)

Asteroids/comets
100 - The technical term for meteorites made mostly of metal.  (Irons)
200 - Any difference between asteroids and comets.  (Composition, location, orbits...)
300 - The term for material with a relatively low melting point, such as cometary ices. (Volatile)
400 - A spherical region in the far outer Solar System harboring huge numbers of comet-like objects.  (Oort cloud)
500 - This process is the reason why meteorites are generally divided into two different types.  (Differentiation)



Impacts, K-T boundary
200 - Qualitatively, the most active period of extraterrestial impact in solar system history.  (Very early on)
400 - The reduced abundance of this surface feature is evidence that the lunar maria are younger than the highlands.  (Impact craters)
600 - The youngest surface in the solar system belongs to this moon of Jupiter.  (Io)
800 - The meteor that killed off the dinosaurs is thought to have struck what is now this country.  (Mexico - Yucatan peninsula)
1000 - One of two processes responsible for the relative absence of craters on Earth's surface.   (Erosion, plate tectonics)


Radioactive dating, ages
200 - The approximate age of the Earth.  (4.5 billion years)
400 - The approximate age of the K-T boundary.  (65 million years)
600 - The age of the Earth is determined most accurately from the ages of these objects.  (Meteorites)
800 - C-14 has a half-life of about 5000 years.  This is the age of a substance that was known to be composed of formerly 1% C-14, if it is 0.25% C-14 today.  (10,000 years)
1000 - ((Draw an isochron graph and ask for a date))

Seismography, Earth interior
200 - The composition and phase of the inner core.  (Solid iron-nickel alloy)
400 - The thickest layer of Earth's interior, composed of rock.  (Mantle)
600 - Shear waves cannot pass through this phase of matter.  (Liquid)
800 - The sound waves that seismologists use to study the interior of the Earth are normally generated by this type of event.  (Earthquakes)
1000 - Variations in this property due to temperature and density allow us to study the properties of the mantle in great detail.  (Sound speed)

Atmosphere, climate
200 - Earth's most important greenhouse gas.  (Carbon dioxide)
400 - The hottest planet in the Solar System.  (Venus)
600 - This process helps keep the temperature at Earth's surface nearly constant.  (Carbon cycle)
800 - In order to be a greenhouse gas, a molecule must have many absorption lines in this part of the spectrum.  (Infrared)
1000 - The periodic "ice ages" in Earths recent history are due to variations in this.  (Earth's orientation and orbit)