Oort cloud
— Noun
– English
~ (astronomy) a hypothetical huge collection of comets orbiting the sun far beyond the orbit of Pluto; perturbations (as by other stars) can upset a comet's orbit and may send it tumbling toward the sun
oort
— Noun
– English
~ Dutch astronomer who proved that the galaxy is rotating and proposed the existence of the Oort cloud (1900-1992)