Ch24 Earth And The Solar System Flashcards
Define axis:
The imaginary line between the earth’s north and south poles
Define orbit:
The path of an object as it moves around a larger object
Define hemisphere:
Half of a sphere; the Earth can be considered to be made of two hemispheres divided by the equator
Defined the equator:
An imaginary line drawn around the Earth halfway between the north pole and the south Pole
Define phases of the moon:
The different ways the moon looks when viewed from earth over a period of one month
Define planet:
A large spherical object that orbits the sun without another similar object close to it
Define minor planet:
An object which orbits the sun, but is not large enough/far enough from another object to be defined as a planet
Define asteroids and meteoroids:
Lumps of rock which orbit the sun
Define comet:
A ball of ice, dust, and gas, which orbits the sun in highly elliptical orbit
Define accretion disc:
A rotating disc of matter formed by accretion
Define accretion:
Coming together of matter under the influence of gravity to form larger bodies
What is the equation for average orbital speed?
Average orbital speed = (2 x π x orbital radius) / orbital period
v = 2πr/T
Define ellipse:
Squashed circle
Define eccentricity:
A measure of how elliptical an orbit is
Define orbital radius:
The average distance of the planet from the sun
