Can new emission-free electric planes replace our polluting airliners and revolutionize personal transportation in our cities? NOVA takes you for a ride in some impressive prototypes that are already in the air, from speedy single-seat planes that can take off like a helicopter but are half as noisy to  "self-flying" air taxis that already taking passengers on test flights in Chinese cities. But if electric airplanes are ever to advance beyond small, short-haul craft, significant hurdles of battery weight, energy storage and cooling remain to be overcome. How long will it be before the dream of super-quiet, super-efficient airliners becomes a reality?

Bats have been implicated in deadly epidemics such as COVID-19 and Ebola, yet scientists are discovering evidence that they may hold the key to a longer and healthier life. From caves in Thailand and Texas to labs around the globe, NOVA meets the scientists decoding the superpowers of the bat.