meteoroid
Học thuậtThân thiện
Definition
Noun: A small, solid body of rock or metal moving through space. It is significantly smaller than an asteroid. When a meteoroid enters a planetary atmosphere, such as Earth's, it heats up and becomes visible as a streak of light called a meteor. If any part of it survives the atmospheric passage and lands on the ground, it is called a meteorite.
Usage
The term "meteoroid" is used specifically in astronomy to describe the object before it interacts with an atmosphere. It is the object in space. - Scientists track meteoroids to assess potential impact risks with Earth. - Most meteoroids that become meteors are no larger than a grain of sand.
Advanced Usage
- Meteoroid stream: A group of meteoroids sharing a similar orbit, often originating from a comet. When Earth passes through such a stream, it results in a meteor shower.
- The Perseid meteor shower is caused by Earth passing through the debris stream, or meteoroid stream, of Comet Swift-Tuttle.
Variants and Related Words
- Meteor (n): The visible streak of light produced when a meteoroid vaporizes in an atmosphere. Often called a "shooting star."
- Meteorite (n): The remnant of a meteoroid that survives its passage through the atmosphere and lands on a planet's surface.
- Micrometeoroid (n): An extremely small meteoroid, typically less than a millimeter in size.
Synonyms
- Space rock: An informal term.
- Cosmic particle: A more general term, often for very small bodies.
Related Phrases
- Meteoroid impact: The event of a meteoroid striking a celestial body.
- The moon's surface shows many craters from past meteoroid impacts.
Noun
- (astronomy) any of the small solid extraterrestrial bodies that hits the earth's atmosphere