The Landsat satellites obtain a daytime image of the same point on Earth every 16 days. The daytime pass crosses the equator between 10:00am and 10:15am (local time). The MODIS instrument is onboard both the Terra and Aqua spacecraft. It views the entire surface of the Earth every one to two days. There are also 8-day, 16-day, monthly, quarterly, and yearly composites of MODIS data.