science unit 1 rp 3

Lightyear

The distance equivalent to what light travels in one year.

AU (Astronomical Unit)

The average distance from the center of the Earth to the center of the Sun.

Terrestrial Planets Spacing

Planets that are much closer together and fairly even in their spacing.

Jovian Planets Spacing

Planets that are very spread out, where the space between them increases as you go further out.

Solar Nebula

A wispy cloud made of gas and dust that collapsed in on itself about $4.6$ billion years ago to form our solar system.

Nuclear Fusion

A process that occurs when hydrogen atoms fuse into helium, which began at the center of the solar disk and created the Sun.

Protostar

A young star.

Planetesimals

Pre-planets formed from clumps of material left behind by the Sun that eventually became planets, dwarf planets, asteroids, comets, and moons.

Asteroid

A small rocky body made of rock that orbits the Sun, located mainly in the Asteroid Belt; it is smaller than a planet and larger than a meteoroid.

Comet

A chunk made of ice and dust (dirty snowball) located in the Kuiper Belt and Oort Cloud, which vaporizes when near the Sun to form a coma and tail.

Meteoroid

A fragment of an asteroid or comet located in space that does not orbit the Sun, which is bigger than a dust grain but smaller than an asteroid.

Meteor

A space rock that enters Earth's atmosphere and starts burning up, creating a streak of light also known as a falling star.

Meteorite

A meteoroid or piece of space rock that reaches Earth's surface without completely burning up.

Dwarf Planet

A small planet that is round because of its own gravity, but is not large enough to clear other bodies out of its orbit.

Planetary System

A group of celestial objects that revolve around a star, including planets, moons, asteroids, and comets.

The Sun ("Sol")

A main sequence star located at the center of the solar system; it is a massive, glowing ball of gas whose gravity holds the solar system together.

Proxima Centauri

The nearest star to our solar system, located $4.2\,LY$ away.

Terrestrial Planets

Also known as inner planets; smaller, rocky planets with solid surfaces, minimal moons, and orbits closest to the Sun (Mercury, Venus, Earth, Mars).

Jovian Planets

Also known as outer planets; larger, gaseous planets with many moons, rings, and gassy surfaces located farthest from the Sun (Jupiter, Saturn, Uranus, Neptune).

Mercury

The smallest planet and closest to the Sun, which lacks an atmosphere, leading to extreme temperature swings.

Venus

The hottest planet in the solar system, featuring a thick, toxic atmosphere of $CO_2$ and sulfuric acid that traps heat and often looks like a star in the night sky.

Earth

The third planet from the Sun, uniquely suited for life due to its perfect balance of water, air, and temperature.

Mars

Known as the "Red Planet" due to its rusty, iron oxide soil; contains no liquid water (only ice) and hosts the largest volcano in the solar system.

Olympus Mons

The largest volcano in the solar system, located on Mars.

Asteroid Belt

A region located between Mars and Jupiter that contains over 100,000 rocky bodies and 1 dwarf planet (Ceres).

Ceres

The single dwarf planet located within the Asteroid Belt.

Jupiter

The largest planet in the solar system by a lot; features a massive storm called the Great Red Spot and a moon named Europa.

Great Red Spot

A famous, large storm located on Jupiter.

Europa

A moon of Jupiter that contains salt water oceans that may harbor life.

Saturn

The second largest planet in the solar system; it is slightly elliptical in shape and is famous for its rings made of ice, rocks, and dust.

Uranus

A blue-colored planet with a narrow ring system that rotates on its side and gets its bluish hue from methane in its atmosphere.

Neptune

The farthest planet from the Sun; a blue planet mostly made of ice, known for its fierce, fast winds and a Giant Dark Spot storm that ended in 1994.

Giant Dark Spot

A notable storm on Neptune that ended in 1994, though others have popped up since.

Kuiper Belt

A donut-shaped region past the planets left over from solar system formation, containing over 100,000 icy/rocky bodies and 4+ dwarf planets.

Pluto

A terrestrial dwarf planet downgraded from a planet, possessing a moon that is large compared to itself and an unusual orbit that overlaps Neptune's orbit.

Oort Cloud

A spherical, icy, cloud-like region located past Pluto that contains comets and leftover dust.