Landsat 5, the oldest satellite watching Earth, is shutting down after almost 30 years

The US Geological Survey will soon shut down Landsat 5, an observational satellite that has been running since 1984. Landsat 5 was designed for a three-year run, but it's now orbited the Earth over 150,000 times and transmitted 2.5 million images in nearly three decades, making it the longest-running Earth-observing satellite, though not the oldest satellite still in orbit. "Any major event since 1984 that left a mark on this Earth larger than a football field was likely recorded by Landsat 5, whether it was a hurricane, a tsunami, a wildfire, deforestation, or an oil spill," says USGS Director Marcia McNutt.

It's also malfunctioned several times in the past, sometimes temporarily going out of commission while being stabilized. On...