Cosmology Vocabulary
Vocabulary Words Terrestrial Planets The Sun Gravity Galaxy Lightyear Axis Comets Kuiper Belt Oort Cloud Meteors AU Nebula Solar System Cosmology Universe Coalescence Jovian Planets Asteroids Dwarf Planets Orbit Planetesimal
Cosmology The study of the origin, properties, process, and the evolution of the universe QuickTime and a decompressor are needed to see this picture.
Universe the totality of everything that exists including planets, stars, galaxies, and all matter and energy. Estimated at 14.5 billion years old.
Lightyear the distance that light travels in a vacuum in one year. Our galaxy is 100,000 light years wide. Proxima Centauri is the closest QuickTime and a decompressor are needed to see this picture. star to our Sun at 4.2 light years away.
Galaxy a collection of star systems. Our is The Milky Way
Solar System The sun & all of the planets & other bodies that travel around it. ~4.6 billion years old ~1.25 light years wide
Gravity the force of attraction between all masses in the universe QuickTime and a decompressor are needed to see this picture.
The Sun the star at the center of the Solar System. Accounts for about 99.86% of the total mass of the Solar System Classified as yellow dwarf star
Sun the star at the center of our Solar System. Accounts for about 99.86% of the total mass of our Solar System Contains mostly hydrogen and helium
Terrestrial Planets Terra = earth like inner, rocky, denser, smaller Mercury Venus Earth Mars
Jovian Planets outer, balls of gas, larger, rings, less dense gas giants and ice giants Jupiter Saturn Uranus Neptune
Asteroids A small orbiting object that does not have characteristics of a planet, moon, or move like a comet. Most are found between Mars and Jupiter usually rocky or metallic. Billions burn up in Earth s atmosphere daily
Comets a small orbiting object that when close enough to the Sun, displays a tail composed of loose collections QuickTime and a decompressor are needed to see this picture. of ice, dust, and small rocky particles. dirty snowballs
Meteoroids/Meteors/Meteorites QuickTime and a decompressor are needed to see this picture. a small object, considerably smaller than an asteroid or comet. Most are fragments from comets or asteroids and varies in composition. Varies in composition.
Dwarf Planet it is a planetary-mass object but does not follow a single gravitation orbit. Significantly smaller than most other planets. Eris & Pluto QuickTime and a decompressor are needed to see this picture.
Kuiper Belt region beyond Neptune where small remnants of the solar system orbit. Like the Asteroid belt but icy instead of rocky QuickTime and a decompressor are needed to see this picture.
Orbit gravitationally curved path of an object around a point in space example the orbit of a planet around center of a star system, typically QuickTime and a decompressor are needed to see this picture. elliptical.
Oort Cloud Small dust particles outer limits of our Solar System consisting of comets. defines the boundary of the Sun's gravitational limits
Axis the angle/tilt between its equatorial plane and orbital plane.
Astronomical Unit is a unit of length, roughly the distance from the Earth to the Sun. The astronomical unit is used primarily as a convenient yardstick for measuring distances within the Solar System.
Coalescence the process by which two or more particles merge during contact to form a single daughter particle. For example, it is seen in the formation of raindrops as well as planetary and star formation. Coalescence the process by which two or more particles merge during contact to form a single daughter particle. For example, it is seen in the formation of raindrops as well as planetary and star formation.
Nebula Latin for cloud a large cloud of gas and dust are often star-forming regions,
Planetismals pre-planet Large masses found in a solar system that are becoming planets. Our planets were planetismals before they were planets.