"The topography determines wetness—the strand ... reassuring an up-to-her-hips-in-swamp-water Streep, "We’re not lost." I stumble into a deep hole and barely catch my balance.

Launched in December 2022, the Surface Water and Ocean Topography (SWOT) Mission houses a first-of-its-kind satellite instrument, KaRin, with an interferometric Ka-band active radar and a near-nadir ...