Earth's Motion Around the Sun and Lunar Phases

These flashcards cover key concepts related to Earth's motion, seasons, lunar phases, and eclipses to aid in exam preparation.

Rotation

The spinning motion of Earth on its axis that takes 24 hours, causing day and night.

Revolution

The motion of Earth around the Sun in a circular path called an orbit, taking 365 days.

December Solstice

Occurs on December 21/22, marking winter in the Northern Hemisphere with the shortest day and longest night.

June Solstice

Occurs on June 20/21, marking summer in the Northern Hemisphere with the longest day and shortest night.

March Equinox

Occurs on March 20/21, where day and night are equal in length, signaling spring in the Northern Hemisphere.

September Equinox

Occurs on September 22/23, where day and night are equal in length, indicating autumn in the Northern Hemisphere.

Waxing

Refers to the moon phases where the illuminated part is increasing.

Waning

Refers to the moon phases where the illuminated part is decreasing.

Solar Eclipse

An event where the Moon is positioned between the Sun and Earth, occurring during a New Moon.

Lunar Eclipse

An event where Earth is positioned between the Sun and Moon, occurring during a Full Moon.

Umbra

The darkest part of a shadow during an eclipse, where total obstruction occurs.

Penumbra

The lighter part of a shadow during an eclipse, where light is partially blocked.

Equator

An imaginary line around the middle of Earth, receiving direct sunlight and thus being warmer than the poles.

Lunar Phases

The cycle of moon phases that include New Moon, Waxing Crescent, First Quarter, Waxing Gibbous, Full Moon, Waning Gibbous, Third Quarter, and Waning Crescent.