  Hydrogen depleted environments are considered an essential requirement for
the formation of fullerenes. The recent detection of C60 and C70 fullerenes in
what was interpreted as the hydrogen-poor inner region of a post-final helium
shell flash Planetary Nebula (PN) seemed to confirm this picture. Here, we
present evidence that challenges the current paradigm regarding fullerene
formation, showing that it can take place in circumstellar environments
containing hydrogen. We report the simultaneous detection of Polycyclic
Aromatic Hydrocarbons (PAHs) and fullerenes towards C-rich and H-containing PNe
belonging to environments with very different chemical histories such as our
own Galaxy and the Small Magellanic Cloud. We suggest that PAHs and fullerenes
may be formed by the photochemical processing of hydrogenated amorphous carbon.
These observations suggest that modifications may be needed to our current
understanding of the chemistry of large organic molecules as well as the
chemical processing in space.
