Astro 300 Test 2

Mesosphere

the part of the earth's atmosphere between the stratosphere and the thermosphere in which temperature decreases with altitude to the atmosphere's absolute minimum.

Great Red Spot

A giant, spinning storm in Jupiter's atmosphere. It is like a hurricane on Earth, but it is much larger. Jupiter's Great Red Spot is more than twice the size of Earth.

Great Dark Spot

A huge spinning storm in the southern atmosphere of Neptune which was about the size of the entire Earth.

Ozone layer

A layer in the earth's stratosphere containing a high concentration of ozone, which absorbs most of the ultraviolet radiation reaching the earth from the sun.

Van Allen radiation belts

A radiation belt is a layer of energetic charged particles that is held in place around a magnetized planet, such as the Earth, by the planet's magnetic field.

Drake Equation

An equation for estimating the number of extraterrestrial civilizations in the galaxy with which we might come in contact.

Caloris Basin

Large crater on Mercury about 1,550 km in diameter, one of the largest impact basins in the Solar System.

3 to 2 Spin Orbit Coupling

Mercury rotates on it's axis 3 times during 2 revolutions around the Sun.

Encke Gap

One of the gaps in the rings of Saturn, and the widest gap in Saturn's A ring.

Retrograde Rotation

Rotation in an opposite direction from the typical rotation within a system.

SETI

Search for Extraterrestrial Intelligence; the attempt to detect signals, esp radiowaves or light, from an intelligent extraterrestrial source.

Shepherd Moons

Small moons that orbit near the inner or outer edges of rings or within gaps in the rings. The gravity of shepherd moons serves to maintain a sharply defined edge to the ring.

Solar Wind

The continuous flow of charged particles from the sun that permeates the solar system.

Cassini Division

The large gap between the two most prominent of Saturn's rings, caused by the gravitational pull of the moon Mimas.

Titan

The largest moon of Saturn. It is the only natural satellite known to have a dense atmosphere, and the only object other than Earth where clear evidence of stable bodies of surface liquid has been found.

Olympus Mons

The largest volcano in the solar system. It is located on Mars.

Stratosphere

The layer of the earth's atmosphere above the troposphere, extending to about 32 miles above the earth's surface (the lower boundary of the mesosphere).

Ionosphere

The layer of the earth's atmosphere that contains a high concentration of ions and free electrons and is able to reflect radio waves. It lies above the mesosphere.

Troposphere

The lowest region of the atmosphere, extending from the earth's surface to a height of about 3.7-6.2 miles, which is the lower boundary of the stratosphere.

Magnetosphere

The region surrounding the earth or another astronomical body in which its magnetic field is the predominant effective magnetic field.

Greenhouse effect

The trapping of the sun's warmth in a planet's lower atmosphere due to the greater transparency of the atmosphere to visible radiation from the sun than to infrared radiation emitted from the planet's surface.

Collison-Ejection Theory

This theory holds that the Moon formed from debris ejected from the Earth when a large object (possibly as large as Mars) crashed into the Earth.