Planets and Moons: Week of May 18-22

orbital radius

the average distance between the sun and an object that is orbiting the sun

Gas giant planets

The outer solar system planets: Jupiter, Saturn, Uranus, and Neptune, composed mostly of hydrogen, helium, and methane.

terrestrial planets

The name often given to the four inner planets: Mercury, Venus, Earth, and Mars.

atmosphere

A mixture of gases that surrounds a planet or moon.

atmospheric pressure

the pressure caused by the weight of the atmosphere

core

The central part of the earth below the mantle

astronomical unit

The average distance between Earth and the sun, about 150 million kilometers- unit used to measure our Solar System

Light Year (LY)

the distance that light can travel in 1 year, which is 9.46 trillion km

Galilean satellites

Io, Europa, Callisto, and Ganymede the 4 largest moons around Jupiter.

Galileo Galilei

This scientist proved Copernicus' theory that the sun was the center of the solar system and developed the modern experimental method. Italian astronomer and mathematician who was the first to use a telescope to study the stars

telescope

A device built to observe distant objects by making them appear closer

Hubble Space Telescope

a space telescope and camera named for a famous astronaut (Edward Hubble) used to study space elements

space probe

a spacecraft that carries scientific instruments that can collect data, but has no human crew and leaves Earth's atmosphere.

Mars Rover

A robot which studies Mars (test soil and studies martian surface)

Sputnik

First artificial Earth satellite, it was launched by Moscow in 1957 and sparked U.S. fears of Soviet dominance in technology and outer space. It led to the creation of NASA and the space race.

artificial satellite

an artificial (man made) body placed in orbit around the earth or moon or another planet in order to collect information or for communication.

dwarf planet

a celestial body resembling a small planet but lacking certain technical criteria that are required for it to be classed as such.

greenhouse gases

Gases such as carbon dioxide, methane, nitrous oxide, water vapor, and ozone in the atmosphere which are involved in the greenhouse effect. Make life possible on planet Earth.

Moon Features

The moon has small and large craters from impacts of meteorites. Maria are flat, dark areas on the moon surface made of cooled lava.

Craters

A large round pit caused by the impact of a meteoroid.

Volcanoes

a mountain or hill, typically conical, having a crater or vent through which lava, rock fragments, hot vapor, and gas are being or have been erupted from the earth's crust.

rift valley

a valley formed by the separation of tectonic plates. A deep valley that forms where two plates move apart.

canyon

a deep, narrow valley with steep sides

mountain

land with steep sides that rises sharply (1,000 feet or more) from surrounding land; generally larger and more rugged than a hill

Asteroids

rocky metallic objects that orbit the sun but are too small to be considered planets

rings (planetary)

a thin disk of small particles of ice and rock