The article indicates how three facts concerning the long-period comets, which hitherto were not well understood, namely the random distribution of o… - Jan Hendrik Oort

The combined effects of the stars and of Jupiter appear to determine the main statistical features of the orbits of comets.

There exists also another type of galaxy agglomeration. These have diameters between roughly one and ten times those of large clusters, but have much smaller densitities; they are usually irregular, with patchy density variations and no central concentration. The larger and most conspicuous of these agglomerations may contain several clusters, which explains why they have been given the name "superclusters." In their longer dimensions, crossing times exceed the age of the Universe. They are thus unrelaxed. Unrelaxed appearance, together with large size, might be taken as a definition of superclusters.

From a score of well-observed original orbits it is shown that the "new" long-period comets generally come from regions between about 50000 and 150000 A.U. distance. The sun must be surrounded by a general cloud of comets with a radius of this order, containing about 10¹¹ comets of observable size; the total mass of the cloud is estimated to be of the order of 1/10 to 1/100 of that of the earth. Through the actlllllllllthis cloud into the vicinity of the sun.