Like a wrecking ball: understanding giant planets as the key to finding Earths

To find truly Earth-like planets, we must understand Jupiter-like planets. Cold giant planets appear to be correlated with small inner planets. Nearly 200 cold giant planets are known from radial-velocity planet searches. But their true masses remain unknown due to the limitations of the technique. Gaia astrometry, paired with the radial velocities, permits measurements of 3-dimensional architecture for these systems. We show examples of Jupiter analogs for which this analysis has made surprising revelations. Understanding full system architectures is critical for modelling their dynamical histories. The presence of giant planets can also disrupt the orbits of inner habitable worlds. Surprisingly, archival radial-velocity data remain unable to exclude giant planets near the habitable zone for many nearby stars to be targeted by future direct imaging surveys such as NASA’s planned Habitable Worlds Observatory. We present results of simulated observing campaigns to determine optimal strategies for thorough vetting of candidate target stars.