While the events of Sept. 11, 2001 were a tragedy, they also offered a rare opportunity to researchers – a chance to observe an empty sky. Because all flights were grounded for days after the attacks, former NASA atmospheric scientist Patrick Minnis documented how the sky changed without the presence of airplane vapor trails – one of the airline industry’s...

Rob Mayeda explains why the sky turned from blue to orange due to the wildfires.

In the wake of the California wildfires, Carnegie Melon University Assistant Professor Coty Jen is sharing the dangers related to the air quality index, which is based on how much dust particles are in the air and can cause breathing issues and respiratory illness.