U1 - Earth, Moon & Sun (24-25)

Scale

Scale

the relative size or proportion of objects compared to each other, often used in models to represent larger or smaller objects at a manageable size

Distance

the amount of space between two objects - typically measured in units like kilometers (km), miles, or astronomical units (AU) in space

Gravity

a force that attracts objects toward each other based on their masses. It keeps planets in orbit around stars and governs the motion of objects in space

Mass

the amount of matter in an object, which determines its gravitational pull. Larger masses exert stronger gravitational forces

Galaxy

a vast system of stars, gas, dust, and dark matter held together by gravity. Our solar system is part of the Milky Way galaxy

Seasons

periods of the year characterized by distinct weather patterns and daylight hours, resulting from Earth's axial tilt and its orbit around the Sun

Tilt

the angle (approximately 23.5 degrees) at which Earth is tilted relative to its orbit around the Sun, affecting how sunlight is distributed on the planet's surface

Orbit

the curved or elliptical path an object takes as it moves around another object due to gravity; such as the orbit of planets around the Sun or moons around planets

Latitude

the angular distance of a place north or south of the Earth's equator, usually measured in degrees (°)

Equator

an imaginary line that circles the Earth horizontally at its center, dividing it into the Northern and Southern Hemispheres. It is located equidistant from the North and South Poles and has a latitude of 0 degrees

Solstices

events that occur twice a year when the Sun reaches its highest or lowest point in the sky at noon, marking the longest and shortest days of the year

Equinoxes

events that occur twice a year when day and night are approximately equal in length, occurring when the Sun is directly above the equator

Sun's Altitude

refers to the angle between the sun and the horizon of Earth, measured in degrees. It changes throughout the day and varies depending on your location on Earth and the time of year

Revolution

refers to a planet's orbit around a star or a moon's orbit around a planet (think 1 year for Earth to go around the sun once)

Rotation

describes the planet's spin on its axis (think day and night on Earth)

Moon Phases

the changing appearances of the moon as seen from Earth, caused by the moon's orbit around Earth and the varying angles of sunlight hitting it

Waxing

when the visible part of the moon is growing larger each night

Waning

when the visible part of the moon is shrinking

Crescent

a phase of the moon where a very small part is illuminated, forming a crescent (banana) shape

Gibbous

a phase of the moon where more than half of it is illuminated but it is not yet full

New Moon

the phase of the moon where the side facing the Earth is completely dark because it's between the Earth and the Sun

Full Moon

the phase of the moon where the side facing the Earth is fully illuminated by the Sun

First Quarter

a waxing phase where the right half of the moon is illuminated and the left half is dark

Third Quarter

a waning phase where the left half of the moon is illuminated and the right half is dark

Solar Eclipse

occurs when the Moon passes between the Earth and Sun, blocking the Sun's light and casting a shadow on the Earth

Lunar Eclipse

happens when the Earth passes between the Sun and Moon, causing the Earth's shadow to fall on the Moon; the moon often appears reddish in color

Umbra

the fully shaded, inner region of a shadow during an eclipse, where the sun's light is completely blocked

Penumbra

the partially shaded outer region of a shadow during an eclipse, where only part of the sun's light is blocked

Illumination

the process of lighting up an object allowing it to become visible; example: the sun's light or illumination

Linear

in a straight line