Bears are taking over Yosemite meadows, and coyotes are wandering city streets. Hilltop sunsets never looked more pure and bright. Around the world, smog-glazed skies are giving way to blue vistas and fresh air. A deadly pandemic is slowing human activity and boosting wildlife in startling ways.

With oil selling at near giveaway prices and airlines virtually grounded, there are fewer emissions pouring out. More widely, tailpipes from millions of cars and trucks are idled by stay-at-home orders. NASA space shots show far less pollution in familiar population and industrial centers across the country.