An asteroid is a rocky space object that orbits the sun, distinct from planets due to its smaller size and irregular shape.
30秒でわかる単語
- A large, rocky object orbiting the sun.
- Found mostly in the belt between Mars and Jupiter.
- Much smaller than planets and irregular in shape.
Overview
An asteroid is essentially a leftover piece from the early formation of our solar system about 4.6 billion years ago. They are primarily composed of rock, metals, and other minerals. While they orbit the sun like planets, they are much smaller and lack the gravitational force to become spherical, often resulting in jagged, potato-like shapes. Most asteroids reside in the 'asteroid belt,' a vast donut-shaped ring located between the orbits of Mars and Jupiter.
Usage Patterns
In English, the word is used both in scientific discussions and casual conversation. It is a countable noun, so it is frequently used in the plural form ('asteroids'). You will often see it paired with verbs like 'orbit,' 'travel,' 'hit,' or 'pass.' When discussing potential hazards, it is common to hear the phrase 'near-Earth asteroid,' which refers to objects whose orbits bring them close to our planet.
Common Contexts
You will encounter this word in science documentaries, news reports about space exploration, and educational settings. It is a staple of astronomy vocabulary. Because of movies and popular science fiction, the word is well-known even among non-scientists. It is often used in discussions regarding the history of Earth, specifically concerning the extinction of dinosaurs, which is widely believed to have been caused by a massive asteroid impact.
Similar Words Comparison: People often confuse 'asteroid' with 'meteor' or 'comet.' An asteroid is a rock in space. A meteor is what we call the streak of light ('shooting star') created when a piece of space debris enters Earth's atmosphere and burns up. A comet, on the other hand, is made mostly of ice and dust and develops a 'tail' when it gets close to the sun. While all three are space objects, their composition and location define their specific names.
例文
The scientist used a telescope to look at the asteroid.
everydayThe scientist used a telescope to look at the asteroid.
NASA tracks several near-Earth asteroids to ensure planetary safety.
formalNASA tracks several near-Earth asteroids to ensure planetary safety.
Did you see that documentary about the asteroid that wiped out the dinosaurs?
informalDid you see that documentary about the asteroid that wiped out the dinosaurs?
The chemical composition of the asteroid suggests it is rich in precious metals.
academicThe chemical composition of the asteroid suggests it is rich in precious metals.
よく使う組み合わせ
よく使うフレーズ
asteroid field
A dense area of asteroids (often in movies).
asteroid impact
A collision event.
よく混同される語
A meteor is the light streak seen when debris enters the atmosphere. An asteroid is the physical rock while it is still in space.
A comet is made of ice and dust and has a tail. An asteroid is made of rock and metal.
文法パターン
How to Use It
使い方のコツ
Asteroid is a neutral, scientific term used across all levels of formality. It is most frequently used in singular or plural forms without needing special modifiers. In scientific writing, it is often categorized as a 'minor planet'.
よくある間違い
Learners often use 'asteroid' to describe a 'shooting star,' which is incorrect. A shooting star is a meteor. Also, ensure you do not use 'asteroid' to refer to stars, which are much larger and made of burning gas.
Tips
Visualize the shape to remember
Think of an asteroid as a floating, jagged potato in space. This helps differentiate it from the perfect spheres of planets.
Don't confuse with meteors
Remember that an asteroid stays in space. Once it enters our atmosphere and glows, it is called a meteor.
Pop culture significance
Many disaster movies feature asteroids as a major plot point. This makes the word very common in everyday English entertainment contexts.
語源
The word comes from the Greek 'asteroeidēs,' meaning 'starlike.' It was coined because, through early telescopes, these objects looked like small, faint stars.
文化的な背景
Asteroids are significant in culture as symbols of both scientific discovery and potential global catastrophe. They are frequently featured in science fiction as mining targets or existential threats.
覚え方のコツ
A-S-T-E-R-O-I-D: Always Stay Traveling, Even Rounding Orbit In Darkness. It is a rocky traveler in the dark of space.
よくある質問
3 問No, asteroids are much smaller than planets. They also lack the gravity to pull themselves into a round shape, which is a key requirement for being classified as a planet.
The majority of asteroids are located in the asteroid belt. This is a vast area between the orbits of Mars and Jupiter.
Yes, it is possible for an asteroid to hit Earth. While most burn up in the atmosphere, large impacts have occurred in the past and are studied by scientists to track potential future risks.
自分をテスト
The ___ orbits the sun between Mars and Jupiter.
An asteroid is the specific term for a rocky body in that orbital region.
スコア： /1
Summary
An asteroid is a rocky space object that orbits the sun, distinct from planets due to its smaller size and irregular shape.
- A large, rocky object orbiting the sun.
- Found mostly in the belt between Mars and Jupiter.
- Much smaller than planets and irregular in shape.
Visualize the shape to remember
Think of an asteroid as a floating, jagged potato in space. This helps differentiate it from the perfect spheres of planets.
Don't confuse with meteors
Remember that an asteroid stays in space. Once it enters our atmosphere and glows, it is called a meteor.
Pop culture significance
Many disaster movies feature asteroids as a major plot point. This makes the word very common in everyday English entertainment contexts.
例文
4 / 4The scientist used a telescope to look at the asteroid.
The scientist used a telescope to look at the asteroid.
NASA tracks several near-Earth asteroids to ensure planetary safety.
NASA tracks several near-Earth asteroids to ensure planetary safety.
Did you see that documentary about the asteroid that wiped out the dinosaurs?
Did you see that documentary about the asteroid that wiped out the dinosaurs?
The chemical composition of the asteroid suggests it is rich in precious metals.
The chemical composition of the asteroid suggests it is rich in precious metals.
クイックテスト
A large ___ is moving in space near the sun.
正解！
正解は： asteroid
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