Unit 2 Earth and Space Systems Flashcards

A collection of key vocabulary terms and definitions covering solar system planets, moon phases, orbital mechanics, tides, and celestial bodies based on Earth and Space Systems lecture notes.

Inner Planets (Terrestrial Planets)

The four planets closest to the Sun, which consist of Mercury, Venus, Earth, and Mars.

Mercury

The closest planet to the Sun and the smallest of all the planets in the solar system.

Venus

The $2\text{nd}$ planet from the Sun, which is about the same size as Earth.

Earth

The $3\text{rd}$ planet from the Sun, which is $4.5\text{ billion years}$ old, supports life with liquid water and an atmosphere of nitrogen and oxygen, and features active plate tectonics.

Mars

The $4\text{th}$ planet from the Sun, which is about $\frac{1}{2}$ the size of Earth.

Outer Planets (Gas Giants)

The four planets farthest from the Sun, which consist of Jupiter, Saturn, Uranus, and Neptune.

Jupiter

The $5\text{th}$ planet from the Sun and the largest planet in the solar system.

Saturn

The $6\text{th}$ planet from the Sun, known for having noticeable rings on it.

Uranus

The $7\text{th}$ planet from the Sun, which rotates on its side / axis.

Neptune

The $8\text{th}$ planet from the Sun, which is about $4\text{ times}$ the size of Earth.

Moon Cycle

A cycle lasting $28\text{ days}$ during which the Moon travels in its path, producing changing light phases based on its alignment with the Sun and Earth.

New Moon

The phase on the first day of the moon cycle where no light can be seen on the Moon.

Waxing Crescent

The moon phase in which $\frac{1}{4}$ of the light can be seen on the Moon.

First Quarter Moon

The moon phase in which $\frac{1}{2}$ of the light can be seen on the Moon.

Waxing Gibbous

The moon phase in which $\frac{3}{4}$ of the light can be seen on the Moon.

Full Moon

The phase of the moon cycle in which the whole lit side of the Moon can be seen.

Gravity

The force that keeps planets in orbit around the Sun, where a greater mass results in a greater gravitational force.

Revolution

The orbit of Earth around the Sun, which takes $365\text{ days}$ to complete.

High Tide

A tide created as the Moon orbits the Earth and ocean waters pull toward the Moon, causing them to bulge outward.

Low Tide

A tide that occurs when water is pulled away from areas not directly aligned with the Moon.

Spring Tides

Exceptionally strong tides with very high high tides and very low low tides that occur during new and full moons when the Sun and Moon line up.

Neap Tides

Weak tides with little difference between high and low water levels that occur during $1\text{st}$ and last quarter moons when the Sun and Moon pull at right angles.

Dwarf Planet

A celestial body (such as Pluto) that orbits the Sun and has enough mass to form a round shape, but has not cleared other objects out of its path.

Comet

An icy object orbiting the Sun that has been described as a dirty snowball.

Meteor

A streak of light in the sky (also known as a falling or shooting star) caused when a meteoroid enters Earth's atmosphere and begins to burn.

Minor Planets (Planetoids)

Small solid objects made of iron, nickel, metal, or any combination of the three that orbit the Sun.

Galileo

An astronomer who used one of the first telescopes in the early 1600s to observe the moons of Jupiter.

Active Plate Tectonics

A process on Earth where the crust is broken into massive, slowly moving plates.