Astronomy

In radioactive dating, the measure scientists use to note how long (on average) a particular radioactive nucleus will take to decay is called its

half-life

During the process of differentiation,

heavier materials sink to the centers of molten planets

In studying the surfaces of solid bodies in the solar system, astronomers have learned that the number of craters (per unit area):

is roughly proportional to the age of the surface we are examining

The inner planets are made mostly of rock and metal because:

it was so hot where the inner planets formed that the lighter materials evaporated

Earthquake producing faults are much more likely to be found

on the boundaries of continental plates, where they meet other plates

The average temperature on planet Earth is higher than you would expect just from the heating of sunlight alone. What is the main explanation for this?

Carbon dioxide (and other gases) in the atmosphere cause a greenhouse effect

In the far future, a visiting tourist from another planetary system asks to see the most massive object in our solar system. Where would you take him/her/it?

The Sun

The Moon is heavily cratered, but Earth which "lives next door" is NOT. Why?

The active geology and weather on Earth destroy traces of impacts over millions of years

Which of the following ways that Jovian planets differ from the terrestrial planets is NOT CORRECT?

jovians rotate significantly more slowly than terrestrials

An important way that scientists have been able to study the interior of the Earth is by:

measuring how seismic waves from Earthquakes are transmitted through the Earth