AU
Astronomical Unit
A unit of length used to measure distances in our solar system
1 AU= the distance from Earth to Sun
Celestial Body
A naturally occuring structure that exists in the universe
IAU
International Astronomical Union
A collection of professional astronomers who study and officially name celestial bodies.
Prograde
When a planet or other celestial body rotates on its axis in a normal direction.
Rotates counterclockwise when looking down from North Pole.
Retrograde
When a planet or other celestial body rotates on its axis in the OPPOSITE direction. Rotates clockwise when looking down from North Pole.
Ex: Venus, Uranus, Pluto
Satellite
A celestial body that orbits another body.
Ex: moon
Kelvin
(K)
One of the 7 base units of measurement in the International Systems of Units (SI). Kelvin measures temperature.
A collection of "space junk" orbiting Earth
Space Debris
Any straight line segment that passes through the center of a circle or sphere. Used to describe the size of a planet or other celestial body
Diameter
A planet that is primarily composed of rock and metals.
"Earth-like"
ex: Mercury, Venus, Earth, Mars
Terrestrial
Composed of two pieces or parts
Binary Asteroid- 2 asteroids orbiting each other
Binary Planets- 2 planets orbiting each other
Binary Star- a solar system with 2 stars
Binary
A chemical compound CH4
(1 carbon atom and 4 hydrogen atoms)
found throughout the solar system. It is a gas in its natural state but can also be found as a liquid and a solid known as methane ice
Methane