Earth's Motion and Astronomy

Earth's Motion Flashcards

Equator

The area of Earth that receives the most direct sunlight, making it warmer than the poles.

Seasons

Earth has these because its axis is tilted as it revolves around the sun.

Earth's Axis Tilt

23.5 degrees from the vertical.

Solstice

Occurs when the Sun reaches its greatest distance north or south of the equator twice a year.

Summer Solstice Date

June 21st

Winter Solstice Date

December 21st

Equinox

Occurs twice a year when neither hemisphere is tilted toward or away from the sun.

Equinox Daylight Hours

12 hours

Spring Equinox Date

March 21st

Autumn Equinox Date

September 22nd

Geocentric Model

"Earth Centered" universe model.

Heliocentric Model

"Sun Centered" universe model.

Foucault Pendulum

Evidence of Earth's rotation.

Coriolis Effect

The apparent deflection of the path of a moving object due to the rotation of Earth.

Planetary Orbits

Ellipses with the Sun at one focus point.

Eccentricity

Measure of how squished an ellipse is.

Eccentricity Formula

distance between foci / length of major axis

Kepler's 1st Law

Planets orbit the sun in slightly elliptical paths with the sun at one of the foci.

Kepler's 2nd Law

The closer a planet is to the sun, the greater its velocity (speed).

Kepler's 3rd Law

Planets that are further away from the sun take longer to orbit than planets closer to the sun.

Lunar Revolution

The revolution of the Moon is responsible for phases, tides, and eclipses.

Moon Formation Theory

Object smashed into Earth, matter was ejected, 4.4 Billion years ago.

Umbra

Total Shadow cast by an eclipse

Penumbra

Partial Shadow cast by an eclipse

Lunar Eclipse

Moon is covered up by the Earth's shadow.

Solar Eclipse

Sun blocked by the moon.