On the observed excess of retrograde orbits among long-period comets

Analysis of the i-distribution of the observed long-period comets points to an excess of retrograde orbits which increases with the perihelion distance. The same behavior is found for the new and very young long-period comets (with semi-major axes greater than 1000 AU). Therefore it is suggested that such excess is not caused by the dynamical aging of the comet population, but is already present in the incoming new comets. It is also shown that a significant fraction of the so-called new comets are actually repeating passages through the planetary region.