The tiny globulettes in the Carina Nebula
  Small molecular cloudlets are abundant in many H II regions surrounding
newborn stellar clusters. In optical images these so-called globulettes appear
as dark silhouettes against the bright nebular background. We have located
close to 300 globulettes in the Carina Nebula. The objects appear as
well-confined dense clumps and, as a rule, lack thinner envelopes, bright rims,
and tails. Some globulettes are slightly elongated with their major axes
oriented in the direction of young clusters in the complex. Many objects are
quite isolated and reside at projected distances >1.5 pc from other molecular
structures in the region. No globulette coincides in position with recognized
pre-main-sequence objects in the area.
  The objects are systematically much smaller, less massive, and much denser
than those surveyed in other H II regions. Practically all globulettes are of
planetary mass, and most have masses less than one Jupiter mass. The average
number densities exceed 10^5 cm^-3 in several objects. We have found a
statistical relation between density and radius (mass) in the sense that the
smallest objects are also the densest.
  The population of small globulettes in Carina appears to represent a more
advanced evolutionary state than those investigated in other H II regions. The
objects are subject to erosion in the intense radiation field, which would lead
to a removal of any thinner envelope and an unveiling of the core, which
becomes more compact with time. We discuss the possibility that the core may
become gravitationally unstable, in which case free-floating planetary mass
objects can form.
