Answer: oort

AnswerCrossword Clue
OORTDutch astronomer
OORTDutch scientist for whom an astronomical "cloud" is named
OORTSolar system's comet-intensive cloud
OORTComet astronomer
OORT... cloud (solar-system region)
OORT... cloud (source of comets)
OORTKind of cloud
OORT... cloud (solar system outlier)
OORT... cloud (region of comets far beyond Pluto)
OORTAstronomy's ... cloud
OORT... cloud (astronomical sighting)
OORTDutch astronomer Jan
OORT... cloud (comet-filled region of space)
OORT... cloud (distant part of the solar system)
OORTComet astronomer, Jan Hendrik
OORT.. cloud (solar-system region)
OORT.. cloud: remote solar system region
OORT.. cloud: comet-filled region in interstellar space
OORT.. cloud: distant solar system region
OORTDutch astronomer who lent his name to a cloud
OORTDutch astronomer who found the first evidence of dark matter
OORT..... cloud: solar system region
OORT... cloud (theoretical source of comets)
OORT.. cloud: solar system region beyond Pluto
OORTAstronomical cloud's name
OORT... cloud (cosmic debris)
OORTDutch astronomer for whom a cloud is named