interplanetary

adjective

in·​ter·​plan·​e·​tary ˌin-tər-ˈpla-nə-ˌter-ē 

: existing, carried on, or operating between planets

interplanetary dust

an interplanetary flight

interplanetary spacecraft

Examples of interplanetary in a Sentence

Recent Examples on the Web

There are other interplanetary missions on Rocket Lab's radar, including its ideas for a Mars Sample Return mission. — Leonard David, Space.com, 3 Sep. 2026

The phenomenon occurs when sunlight reflects off interplanetary dust grains along the inner solar system, with late September offering optimal conditions for early risers in dark-sky regions. — Michael D'estries, Travel + Leisure, 1 Sep. 2026

Although Hal’s remit encompasses the entire interplanetary backwater that includes Earth, Lanterns takes place mostly in the rural American town of Rushville, Neb. — Judy Berman, Time, 14 Aug. 2026

Visibility depends on factors like solar wind and the interplanetary magnetic field. — Jamie Carter, Forbes.com, 2 Aug. 2026

Word History

First Known Use

1691, in the meaning defined above

Rhymes for interplanetary

• beneficiary
• bronchopulmonary
• evolutionary
• expeditionary
• extramedullary
• extraordinary
• extrapulmonary
• genitourinary
• geostationary
• hepatobiliary
• illocutionary
• insurrectionary

Kids Definition

interplanetary

adjective

in·​ter·​plan·​e·​tary

ˌint-ər-ˈplan-ə-ˌter-ē

: between planets

interplanetary space

interplanetary travel