Fundamental Science Achieved with a Single Probe in Each Giant Planet Atmosphere

Recent observations of Jupiter’s atmosphere showing unexpected depletion of ammonia below the ammonia cloud-forming region has brought up the question of whether a single point measurement below the cloud decks in a giant planet atmosphere can provide sufficient information to answer fundamental science questions. We outline here the science questions that can only be answered by in situ observations in the giant planet atmospheres, many of which are location invariant. These questions are identified in the recent planetary science decadal survey as high priority for answering over the next decade. We evaluate the implications of the ammonia observations at Jupiter for the specific measurements needed and demonstrate that they do not invalidate single point measurements made to answer these questions.