Space & Universe Vocabulary in English
20 essential space and astronomy words with meanings, example sentences, and free interactive games — ideal for B1–B2 learners.
Space and universe vocabulary is one of the most fascinating topic areas in English. Whether you are reading a science article, watching a documentary, studying for an English exam, or simply curious about the cosmos, knowing the key terms used in astronomy and space exploration will help you engage with some of the most compelling content in the English language.
This page covers 20 essential space and universe words at B1 to B2 level. Each entry includes a clear scientific definition written in accessible language, plus a natural example sentence to show the word used in real English contexts. Many of these words also appear in scientific essays, IELTS Reading passages, and Cambridge English exam texts.
Space vocabulary is particularly interesting because many of these words have figurative uses in everyday English as well. Orbit can describe a path in space or a sphere of influence in politics. Gravity can mean the physical force or the seriousness of a situation. Universe is used metaphorically to describe any complete world or system. Learning these words therefore enriches both your scientific and your general English.
For related vocabulary, explore our Science and Environment pages, which cover other areas of natural and physical science at B1 to B2 level.
Essential Space & Universe Words
| Word | Meaning | Example Sentence | Level |
|---|---|---|---|
| asteroid | a rocky body smaller than a planet that orbits the sun, mostly found in the asteroid belt between Mars and Jupiter | Scientists track thousands of asteroids to detect any that might approach Earth. | B1 |
| astronaut | a person trained to travel and work in space | The astronaut spent six months on the International Space Station. | B1 |
| atmosphere | the layer of gases surrounding a planet, held in place by gravity | Earth's atmosphere protects us from harmful radiation from the sun. | B1 |
| black hole | a region in space where gravity is so strong that nothing, not even light, can escape it | The first image of a black hole was captured by astronomers in 2019. | B2 |
| comet | a small icy body that travels through the solar system and develops a bright tail when close to the sun | Halley's Comet is visible from Earth approximately every 75 years. | B1 |
| cosmos | the universe seen as a complex and orderly system; all of space and everything in it | Carl Sagan's TV series explored humanity's place in the cosmos. | B2 |
| galaxy | a system of billions of stars, gas, and dust held together by gravity | Our solar system is located in the Milky Way galaxy. | B1 |
| gravity | the natural force that attracts objects with mass toward each other | Gravity keeps planets in orbit around the sun and holds the moon near Earth. | B1 |
| meteor | a piece of rock or metal that enters Earth's atmosphere and burns up, creating a bright streak of light | We watched a meteor shower from the hillside on a clear summer night. | B1 |
| moon | a natural satellite that orbits a planet; the Earth's own natural satellite | The moon takes approximately 27 days to orbit the Earth. | B1 |
| nebula | a large cloud of gas and dust in space, often where new stars are forming | The Orion Nebula is one of the most photographed objects in the night sky. | B2 |
| orbit | the curved path of one object around another due to gravity; also used as a verb | The satellite orbits the Earth once every 90 minutes. | B1 |
| planet | a large spherical body that orbits a star and has cleared its orbital path of other debris | There are eight recognised planets in our solar system. | B1 |
| rocket | a vehicle powered by engines that expel gas to propel it through space | The rocket launched successfully and reached orbit within minutes. | B1 |
| satellite | an object that orbits a planet; also refers to human-made objects launched into orbit | Weather satellites collect data that is used to forecast rain and storms. | B1 |
| solar system | the sun and all the planets, moons, asteroids, and comets that orbit it | Pluto was reclassified as a dwarf planet and removed from the list of solar system planets. | B1 |
| spacecraft | a vehicle designed for travel or operation in outer space | The spacecraft took seven months to travel from Earth to Mars. | B1 |
| star | a massive luminous ball of plasma held together by gravity; the sun is a star | On a clear night you can see thousands of stars with the naked eye. | B1 |
| telescope | an instrument that makes distant objects appear larger and closer, used to observe space | The James Webb Space Telescope has captured extraordinary images of distant galaxies. | B1 |
| universe | all existing matter, space, and energy; everything that exists | Scientists believe the universe began approximately 13.8 billion years ago. | B1 |
Practice Space & Universe Vocabulary
Flash Cards
Review space words with spaced repetition
Word Search
Find space terms hidden in the grid
Quiz
Test your astronomy vocabulary knowledge
Hangman
Guess space words letter by letter
Practice What You've Learned
LexFizz has 30 free interactive exercises — no sign-up needed.
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Frequently Asked Questions
What is the difference between a meteor, a meteoroid, and a meteorite?
A meteoroid is a small rock or piece of metal floating in space. When it enters Earth's atmosphere and burns up, producing a streak of light, it is called a meteor (or a shooting star). If it survives the journey through the atmosphere and lands on Earth's surface, it is called a meteorite. These three words are commonly confused, even by native speakers, so knowing the distinction is impressive at B2 level.
What is the difference between a planet and a star?
A star is a massive ball of hot plasma that produces its own light and heat through nuclear fusion — the sun is a star. A planet is a large spherical body that orbits a star but does not produce its own light; it reflects light from the star it orbits. Our solar system has one star (the sun) and eight planets. Stars are typically much larger and far more distant than planets.
What does orbit mean in English and how is it used as both a noun and a verb?
As a noun, orbit refers to the curved path an object takes around another object due to gravity: The moon is in orbit around the Earth. As a verb, orbit means to travel in such a path: The satellite orbits the Earth. The adjective orbital is also common: an orbital station. Understanding how a word works as both a noun and a verb is important for IELTS and Cambridge English writing tasks.
Why is space vocabulary important for English learners?
Space and astronomy topics appear regularly in IELTS Academic Reading passages, Cambridge English CAE and CPE texts, and general reading about science and technology. Words like atmosphere, gravity, orbit, and satellite also have figurative uses in everyday English — knowing both meanings makes you a stronger reader. Space topics are also common in IELTS Writing Task 2 essay prompts about science funding and exploration.
What is the difference between the solar system, a galaxy, and the universe?
These three terms describe different scales of space. The solar system is the sun and everything that orbits it — our eight planets, their moons, asteroids, and comets. A galaxy is a much larger system of billions of stars, gas, and dust — our solar system is just one tiny part of the Milky Way galaxy. The universe is everything: all matter, all energy, all space, and all galaxies combined. Think of it as nested levels of scale: solar system inside a galaxy inside the universe.
What is a black hole and why is it significant?
A black hole is a region in space where gravity is so extreme that nothing — not even light — can escape it. Black holes form when massive stars collapse at the end of their lives. They are significant because they represent the extreme limits of known physics, and studying them helps scientists understand gravity, time, and the structure of the universe. In English, black hole is also used figuratively to describe something that consumes all resources without producing anything useful.
What is the difference between cosmos and universe?
Both cosmos and universe refer to all of space and everything in it, so they are very close in meaning. Universe is the more common and neutral word in science. Cosmos (from Greek) is used more often in philosophical or poetic contexts, suggesting the universe as an ordered, beautiful system. In everyday English, universe is the safer choice. Cosmos appears frequently in the titles of science books and documentaries.
How do you spell nebula and what is its plural?
Nebula is spelled n-e-b-u-l-a. It comes from Latin and means mist or cloud. The Latin plural is nebulae (neb-you-lee), but the English plural nebulas is also widely accepted and used in informal contexts. Scientific writing tends to use nebulae. Other Latin-origin words with similar patterns in astronomy include formula (formulae) and antenna (antennae).
What is the difference between a satellite and a spacecraft?
A satellite is any object that orbits a planet or other body — this includes natural satellites like moons and artificial ones launched by humans. A spacecraft is any vehicle designed for travel in outer space. All human-made satellites are spacecraft, but not all spacecraft are satellites — for example, the Apollo missions sent spacecraft to land on the moon rather than orbit Earth. Rockets are used to launch spacecraft into space.
How can I practise space vocabulary in English?
Use LexFizz Flash Cards to learn the definitions, then test yourself with the Quiz and Hangman exercises to practise under recall conditions. To reinforce vocabulary in context, read articles from NASA's website or the BBC Science section, both of which are written in clear, accessible English. Space documentaries in English — with subtitles if needed — also expose you to these words in natural spoken language.