Variable Atmospheric Composition Sampled by Probes

Science highlights from in-situ observations of variable atmospheric composition will be presented, ranging from mysterious fluctuations in oxygen and methane on Mars, to unexpectedly deep depletions of cloud-forming gases on Jupiter. In future years, probes may visit Saturn, Uranus, and Neptune to solve mysteries revealed by current remote sensing and modeling studies. An exciting opportunity in an environment with healthy federally-funded space exploration is the possibility to send small secondary probes into giant planet atmospheres, to obtain in-situ data at multiple locations. Composition measurements by small probes would be enabled by chip-scale gas sensors, capable of accurate composition measurements but with much smaller resource requirements compared to flagship-class mass spectrometers.