outer planet

noun 0.670

giant planet

noun 0.650

planetary system

noun 0.641

planet

noun 0.629

terrestrial planet

noun 0.617

inner planet

noun 0.609

planetary

noun 0.608

planetary nebula

noun 0.594

planetesimal

noun 0.592

dwarf planet

noun 0.589

gas giant

noun 0.584

protoplanet

noun 0.582

planetoid

noun 0.581

exobiology

noun 0.565

minor planet

noun 0.564

interplanetary space

noun 0.557

outer space

noun 0.547

planetology

noun 0.546

celestial object

noun 0.543

planetary science

noun 0.540

solar system

noun 0.537

other world

noun 0.534

planetary ring

noun 0.533

protoplanetary disk

noun 0.533

binary star

noun 0.527

exobase

noun 0.525

extrahuman

noun 0.525

exocentric

noun 0.522

space satellite

noun 0.520

exotic

noun 0.518

external

noun 0.518

exospore

noun 0.516

space exploration

noun 0.515

ectoparasite

noun 0.512

astrobiologist

noun 0.509

supernova

noun 0.507

interstellar space

noun 0.506

heavenly body

noun 0.506

asteroid

noun 0.505

solar eclipse

noun 0.505

binary star system

noun 0.504

ectopic

noun 0.502

alien

noun 0.502

exosystem

noun 0.500