Astro2020 Science White Paper: Triggered High-Priority Observations of Dynamic Solar System Phenomena

Unexpected dynamic phenomena have surprised solar system observers in the past and have led to important discoveries about solar system workings. Observations at the initial stages of these events provide crucial information on the physical processes at work. We advocate for long-term/permanent programs on ground-based and space-based telescopes of all sizes - including Extremely Large Telescopes (ELTs) - to conduct observations of high-priority dynamic phenomena, based on a predefined set of triggering conditions. These programs will ensure that the best initial dataset of the triggering event are taken; separate additional observing programs will be required to study the temporal evolution of these phenomena. While not a comprehensive list, the following are notional examples of phenomena that are rare, that cannot be anticipated, and that provide high-impact advances to our understandings of planetary processes. Examples include: new cryovolcanic eruptions or plumes on ocean worlds; impacts on Jupiter, Saturn, Uranus, or Neptune; extreme eruptions on Io; convective superstorms on Saturn, Uranus, or Neptune; collisions within the asteroid belt or other small-body populations; discovery of an interstellar object passing through our solar system (e.g. 'Oumuamua); and responses of planetary atmospheres to major solar flares or coronal mass ejections.