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

According to EarthSky, the zodiacal light is sunlight reflecting off a vast cloud of interplanetary dust that lines the same path as the zodiac constellations. —Valerie Mesa, PEOPLE, 17 Apr. 2026

This interplanetary outing picks up nine years after the Goldilocks asteroid heist in 2012 as a new generation emerges while our principal characters enjoy their silver years. —Jeff Spry, Space.com, 10 Apr. 2026

Throughout the eclipse, the astronauts will search for a second type of dust as well, this time in the form of zodiacal light, which is caused by sunlight reflecting off interplanetary dust. —Meghan Bartels, Scientific American, 6 Apr. 2026

This slightly decreases the total mass of objects in interplanetary space — the material and space between planets — while slightly increasing the masses of the planets themselves. —Big Think, 31 Mar. 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