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

The separation placed the sample-return spacecraft on its interplanetary trajectory toward Mars and Phobos, marking a key milestone in the mission. — Aamir Khollam, Interesting Engineering, 19 Oct. 2026

The interplanetary transit will last about 10 months, with the spacecraft scheduled to arrive at the Red Planet in August 2027. — Josh Dinner, Space.com, 19 Oct. 2026

The remarkable human brain that conceived heart surgery and interplanetary travel runs on roughly the same amount of energy as a refrigerator bulb, thanks to its trillions of synapses. — New Atlas, 18 Oct. 2026

Having multiple worlds all in one orbit might be handy for interplanetary travel. — Phil Plait, Scientific American, 16 Oct. 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