The SMAP Orbital Track & Overpass Time (Descending/Day) layer is the path of the Soil Moisture Active Passive satellite on its descending/day-time orbit. Overpass times are shown in Coordinated Universal Time (UTC). SMAP is at a 685-km altitude, near-polar, sun-synchronous 6am/6pm, 8-day exact repeat, frozen orbit.

Orbital Track information from https://www.space-track.org/.