I remember learning about this back in highschool. THis seems to fit the description of what were seeing.
"There has been much speculation that any life on
Jupiter, or on other
gas giants, might be
ammonia-based life. The possibility of "abundant biota" in the upper regions of Jupiter's atmosphere was considered in a 1976 paper by Carl
Sagan and Edwin E. Salpeter1, three years after the fly-by of the first Jupiter probe,
Pioneer 10. Sagan and Salpeter compared the ecology of the Jovian atmosphere with that of terrestrial seas which have simple
photosynthetic plankton
at the top level, fish at lower levels feeding on these creatures, and
marine predators which hunt the fish. The three hypothetical Jovian
equivalents of these organisms, Sagan and Salpeter termed "sinkers",
"floaters", and "hunters". They envisaged creatures like giant gas-bags
(see
bubble life) that move by pumping out
helium and calculated that the "hunter" variety might grow to be many kilometers across (and therefore visible from space).
Jovian aerial life-forms like those described by Sagan and Salpeter are portrayed in Arthur C.
Clarke's short story "A Meeting with Medusa" (in
The Wind From the Sun). Ben
Bova refers in his novel
Jupiter to
"[H]uge
balloonlike creatures called Clarke's Medusas that drifted in the
hurricane-like winds surging across the planet. Birds that have never
seen land, living out their entire lives aloft. Gossamer spider-kites
that trapped microscopic spores. Particles of long-chain carbon
molecules that form in the clouds and sift downward, toward the global
ocean below."
Bova speculates
further that, in the high-pressure, liquid hydrogen ocean that lies
below Jupiter's thick atmosphere, are colossal, city-sized creatures
with intelligence. He follows the exploits of one of these sentient
giants – Leviathan: Predators
swarmed through Leviathan's ocean: swift voracious Darters that struck
at Leviathan's kind and devoured their outer members.
In recent years,
astrobiological interest in the jovian system has shifted from Jupiter
itself to its larger moons, especially
Europa,
Ganymede, and
Callisto. Read also about the possibilities for life on
Mars,
Venus, and for
extraterrestrial life in general."