apollo asteroid: meaning, definition, pronunciation and examples
Rare / TechnicalTechnical / Scientific
Quick answer
What does “apollo asteroid” mean?
A near-Earth asteroid whose orbit crosses Earth's orbit, similar to the orbit of the asteroid 1862 Apollo.
Audio
Pronunciation
Definition
Meaning and Definition
A near-Earth asteroid whose orbit crosses Earth's orbit, similar to the orbit of the asteroid 1862 Apollo.
In a broader astronomical context, any of the asteroids belonging to the Apollo group, which are defined by having a semi-major axis greater than 1 AU (like Earth's) but a perihelion distance less than Earth's aphelion (so their orbits cross Earth's). They are one of the primary classes of potentially hazardous objects due to their intersecting orbits.
Dialectal Variation
British vs American Usage
Differences
No significant differences. Both dialects use the same term with standard scientific spelling and pronunciation. The capitalisation of 'Apollo' is consistent, as it is a proper name.
Connotations
Neutral scientific classification in both varieties.
Frequency
Equally low frequency in both UK and US English, confined to astronomical literature, science journalism, and educational contexts.
Grammar
How to Use “apollo asteroid” in a Sentence
[Apollo asteroid] + [orbital verb: crosses, approaches, passes] + [Earth/the Moon]Scientists + [classified/identified] + [object] + as + an Apollo asteroid.The + [Apollo asteroid] + [was discovered] + [in year].Vocabulary
Collocations
Examples
Examples of “apollo asteroid” in a Sentence
verb
British English
- The object was Apollo-classified after its orbit was calculated.
- We need to Apollo-categorise these new NEOs.
American English
- The object was Apollo-classified after its orbit was calculated.
- We need to Apollo-categorize these new NEOs.
adjective
British English
- The Apollo-type object posed a negligible risk.
- Their research focuses on Apollo-group dynamics.
American English
- The Apollo-type object posed a negligible risk.
- Their research focuses on Apollo-group dynamics.
Usage
Meaning in Context
Business
Extremely rare. Only in specialised contexts like asteroid mining or space insurance.
Academic
Standard term in astronomy, planetary science, and astrophysics papers and textbooks.
Everyday
Virtually never used in casual conversation unless discussing astronomy news (e.g., a close approach reported in media).
Technical
The primary domain of use. Precise classification in orbital mechanics, risk assessment, and space mission planning.
Vocabulary
Synonyms of “apollo asteroid”
Strong
Neutral
Weak
Vocabulary
Antonyms of “apollo asteroid”
Watch out
Common Mistakes When Using “apollo asteroid”
- Writing 'apollo asteroid' in lowercase (should be capitalised as it's a proper name).
- Confusing it with 'Apollo program' (space missions) though the words are identical.
- Using it as a general term for any near-Earth asteroid (it's a specific orbital class).
FAQ
Frequently Asked Questions
No. While their orbits cross Earth's, most are small and the probability of impact with Earth for any specific one is extremely low over human timescales. Only a subset are classified as 'Potentially Hazardous' based on size and minimum orbital intersection distance.
Both are near-Earth asteroids (NEAs). Apollo asteroids have orbital periods longer than a year (semi-major axis > 1 AU) but come within Earth's orbit at perihelion. Aten asteroids have orbital periods shorter than a year (semi-major axis < 1 AU) but cross Earth's orbit at aphelion.
It is named after the first asteroid of this type to be discovered, 1862 Apollo, which was found in 1932. The asteroid itself was named after the Greek god Apollo.
Typically not with the naked eye. Most are too small and faint. During a very close approach, a larger one might be visible through telescopes or binoculars. Discoveries and tracking are done by professional observatories.
A near-Earth asteroid whose orbit crosses Earth's orbit, similar to the orbit of the asteroid 1862 Apollo.
Apollo asteroid is usually technical / scientific in register.
Apollo asteroid: in British English it is pronounced /əˈpɒləʊ ˈæstərɔɪd/, and in American English it is pronounced /əˈpɑloʊ ˈæstəˌrɔɪd/. Tap the audio buttons above to hear it.
Phrases
Idioms & Phrases
- “None. The term is purely technical and does not feature in idiomatic expressions.”
Learning
Memory Aids
Mnemonic
Think: 'APOLLO missions went to the Moon, crossing Earth's orbit. APOLLO asteroids also cross Earth's orbit.' (Note: The etymology is from the asteroid's name, not the mission, but the mnemonic links the concept of crossing.)
Conceptual Metaphor
Often framed as a 'visitor' or 'intruder' in Earth's orbital neighbourhood, or as a 'celestial bullet' in risk contexts.
Practice
Quiz
What primarily defines an Apollo asteroid?