# Astronomy & Space

**Type:** Topic
**Words:** 59

## About

Stars, planets, cosmic phenomena, space exploration, and astronomical observation.

## Words by Level

### A1
- sun — The star that gives light and heat to the Earth and the other planets.; frequency rank 830
- star — A bright point of light seen in the night sky.; frequency rank 889

### A2
- planet — A large round object in space that moves around a star such as the Sun.; frequency rank 1089
- moon — The large round object that shines in the sky at night and circles the Earth.; frequency rank 1126
- astronaut — A person who is trained to travel and work in space.; frequency rank 7132
- spaceship — A vehicle designed to carry people through space.; frequency rank 7422

### B1
- universe — Everything that exists, including all of space, time, and matter.; frequency rank 1614
- launch — To start something new, such as a product, project, or campaign.; frequency rank 2986
- atmosphere — The layer of gases that surrounds the Earth or another planet.; frequency rank 3332
- satellite — A machine sent into space to orbit the Earth and send back signals or information.; frequency rank 4054
- radiation — Energy that travels as rays, waves, or particles, such as heat or light.; frequency rank 4417
- orbit — The curved path an object follows as it circles a planet, star, or other body in space.; frequency rank 5430
- horizon — The line in the distance where the sky seems to meet the land or sea.; frequency rank 6975
- comet — A small icy body in space that travels around the Sun and grows a bright glowing tail as it gets close to it.; frequency rank 7332
- capsule — A small, smooth case containing medicine that you swallow whole.; frequency rank 9178
- meteor — a streak of light produced when a small piece of matter from space enters Earth's atmosphere and becomes intensely hot; frequency rank 9197
- orbital — relating to an orbit or to motion around another body; frequency rank 19044
- astronomer — A scientist who studies the stars, planets, and the universe.; frequency rank 19113

### B2
- revolution — A sudden, often violent attempt by people to overthrow a government and change the political system.; frequency rank 2707
- rocket — A vehicle or device driven through the air or space by burning fuel.; frequency rank 3546
- solar — Relating to the sun.; frequency rank 4173
- telescope — An instrument that makes distant objects look closer and larger, especially stars and planets.; frequency rank 8131
- crater — A large bowl-shaped hole in the ground made by an impact or explosion.; frequency rank 10987
- astronomy — The scientific study of the stars, planets, and the universe.; frequency rank 15209
- meteorite — a piece of rock or metal from space that survives passage through an atmosphere and reaches the ground; frequency rank 15568
- supernova — an extremely energetic stellar explosion that makes a star suddenly become vastly more luminous; frequency rank 18683
- wavelength — a shared orientation leading to mutual understanding; frequency rank 21027
- spacecraft — a vehicle designed to travel or operate in outer space

### C1
- gravity — The natural force that pulls objects toward the earth or toward each other.; frequency rank 4160
- vacuum — A space that contains no matter or air.; frequency rank 6310
- aurora — a display of colored light in the polar sky caused by charged solar particles interacting with the upper atmosphere; frequency rank 11572
- spectrum — A wide range of related ideas, opinions, qualities, or things.; frequency rank 11765
- rotation — The act of turning around a central point or axis.; frequency rank 11894
- interstellar — situated, occurring, or traveling between stars; frequency rank 21075
- terrestrial — operating or living or growing on land; frequency rank 27875
- exoplanet — a planet located outside our solar system

### C2
- galaxy — a vast gravitationally bound system of stars, gas, dust, dark matter, and other astronomical objects; frequency rank 4480
- cosmic — Relating to the universe or outer space.; frequency rank 7340
- asteroid — a natural rocky or metallic body smaller than a planet that orbits a star, especially one orbiting the Sun; frequency rank 8725
- rover — a person who wanders or travels without settling in one place; frequency rank 9089
- lunar — of or relating to or associated with the moon; frequency rank 10849
- gravitational — Relating to or caused by gravity.; frequency rank 12389
- zodiac — the belt of the sky centered on the ecliptic through which the sun, moon, and visible planets appear to move; frequency rank 14055
- nebula — an interstellar cloud of gas and dust, often associated with the formation or death of stars; frequency rank 15215
- stellar — Exceptional, exceptionally good.; frequency rank 17272
- solstice — either of the two annual times when the sun reaches its greatest apparent distance north or south of the celestial equator, producing the longest or shortest day; frequency rank 22934
- equinox — either of the two times each year when the Sun crosses the celestial equator and day and night are approximately equal in length; frequency rank 27064
- cosmology — the scientific study of the origin, structure, development, and possible fate of the universe; frequency rank 33560
- quasar — an extremely luminous active galactic nucleus powered by matter falling into a supermassive black hole; frequency rank 48360

### C2+
- celestial — relating to the sky or heavens, or to heaven in a divine sense
- eclipse — the obscuring of one celestial body by another; to outshine
- crescent — a curved shape like the partly lit moon
- astronomical — extremely large; relating to astronomy
- cosmos — the universe regarded as an ordered, harmonious whole
- nadir — the lowest or most unsuccessful point; the point opposite the zenith
- observatory — a building equipped for observing astronomical or natural phenomena
- constellation — a recognized pattern of stars, or any grouping of related things
- planetary — relating to a planet or planets
- zenith — the highest point reached; the point in the sky directly overhead