Earth and the Solar System

Vocabulary flashcards covering Earth's rotation, revolution, Moon phases, eclipses, tides, and classification of celestial bodies based on the lecture notes.

Earth's Rotation

The movement of Earth spinning on its axis, which takes approximately $23\text{ hours, } 56\text{ minutes, and } 4\text{ seconds}$ (rounded to $24\text{ hours}$).

Daily Apparent Motion

The perceived movement of celestial bodies across the sky from east to west caused by Earth's rotation.

Equatorial Bulging

An effect of Earth's rotation resulting in a bulge at the equator and flattening at the poles.

Earth's Revolution

The movement of Earth orbiting the Sun, taking approximately $365.25\text{ days}$.

Ecliptic

The plane of Earth's orbit as it revolves around the Sun.

Earth's Axial Tilt

The angle of Earth's axis, which is tilted at $66.5^\text{o}$ to the ecliptic plane or $23.5^\text{o}$ relative to the line perpendicular to the ecliptic.

GBU (Garis Balik Utara)

The northernmost latitude ($23.5^\text{o}\text{LU}$) where the Sun appears to reach its maximum shift during its annual apparent motion.

GBS (Garis Balik Selatan)

The southernmost latitude ($23.5^\text{o}\text{LS}$) where the Sun appears to reach its maximum shift during its annual apparent motion.

Moon Phase

The changing appearance of the Moon as seen from Earth, caused by the Moon's position relative to the Sun and Earth.

Lunar Eclipse

A phenomenon that occurs when Earth is positioned between the Sun and the Moon, blocking sunlight from reaching the Moon.

Umbra

The darkest part of a shadow during an eclipse; for example, when the Moon passes entirely through this area, a total lunar eclipse occurs.

Penumbra

The lighter, outer part of a shadow; a penumbral lunar eclipse occurs when the Moon passes through this shadow.

Solar Eclipse

A phenomenon that occurs when the Moon is positioned between the Sun and Earth, blocking sunlight from reaching Earth.

Annular Solar Eclipse

A type of eclipse where the Moon covers the Sun's center, leaving the Sun's visible outer edges to form a "ring of fire."

Spring Tide (Pasang Purnama)

The maximum tide occurring when the Earth, Moon, and Sun are aligned in a straight line, combining their gravitational pulls.

Neap Tide (Pasang Perbani)

The minimum tide occurring when the Moon, Earth, and Sun form a right angle ($90^\text{o}$).

Jovian Planets

Planets composed primarily of hydrogen and helium gas, including Jupiter, Saturn, Uranus, and Neptune.

Terrestrial Planets

Solid, rocky planets including Mercury, Venus, Earth, and Mars.

Meteor

Fragments of asteroids or comets that burn up completely upon entering Earth's atmosphere.

Meteorite

A meteor that does not burn up completely in the atmosphere and successfully reaches the Earth's surface.

Apehelium

The point in an orbit where a celestial body is furthest from the Sun.

Perihelium

The point in an orbit where a celestial body is nearest to the Sun.