The two most common elements in the Earth's CRUST are

The density of the Earth is calculated to be about

Scientists use ____ waves to determine the composition of the interior of the planet .

Type of seismic wave that can travel through solids, liquids and gases.

Type of seismic wave that can travel through solids only.

thinnest, least dense layer of solid, mostly silicate rocks

thickest layer, mostly solid but capable of flow when stressed

liquid layer responsible for the magnetic field

solid layer due to intense pressure, composed of mostly iron and nickel

Process by which heated matter becomes less dense and rises, and cooler matter becomes more dense and sinks, resulting in a current.

Process where currents collide with each other and one part of the crust is forced below the other and melted

Process where currents drags the surface crust, shifting and stretching the crust apart

Which of the following is NOT evidence supporting plate tectonics?

The age of the Earth is calculated to be about

The radius of the Earth is about

Earth's magnetic field is generated by ___ ___ in the molten outer core.

The magnetic field is believed to have developed from a combination of

The polarity of the magnetic field reverses every

The magnetic field deflects dangerous particles from the Sun into two doughnut shaped regions called

Charged particles in the Van Allen belts generate electric current in the upper atmosphere, causing a phenomenon known as

Which layer of the atmosphere contains the ozone layer?

Which layer of the atmosphere has the highest air pressure?

Approximately how much NITROGEN by percent is in our atmosphere?

Approximately how much OXYGEN by percent is in our atmosphere?

Approximately how much ARGON by percent is in our atmosphere?

Approximately how much CARBON DIOXIDE by percent is in our atmosphere?

Visible light passes through the atmosphere and is converted to infrared energy, which is then trapped by the atmosphere. This is called

The deflection of moving objects across the surface of a spinning body.

The slow change in the direction of the rotation axis of a spinning body (aka wobble).

Scientists study organisms called ___ because they provide boundaries within which we think life can exist.

Which of the following is not one of the six elements that make up most compounds necessary for life?

Which of the following are NOT the three features of cells that are necessary for any form of life?

Idea that life was seeded on Earth by asteroids, meteors, and comets containing primitive biomolecules

The Miller Urey experiment combined simple molecules thought to be part of Earth's early atmosphere into what biomolecules?

What is the Habitable Zone?

There are several objects in our solar system of interest to astrobiologists. Which of the following is NOT one of them?

An equation with many factors that attempts to determine how many worlds exist that could possibly be home to intelligent civilizations

Discrepancy between the apparently high likelihood of intelligent civilizations and the fact that we have no current evidence of intelligent civilizations

Possible explanation to explain lack of intelligent civilizations that states that every civilization experiences some barrier to its own survival

Name of the spacecrafts that contained the Golden Record, a nearly two hour selection of audio and music of Earth.

Name of the institute that studies radio and optical waves for traces of intelligence.