Liepert mentioned all this near the end of a drive the other day
from upper Manhattan to an airfield in western New Jersey, where
she was to embark on a flight in a hot-air balloon. A
passenger’s initial unease over the balloon flight—“We go up to
six thousand feet,” Liepert had said, “and we have no safety
equipment”—had been displaced by that of riding in a rickety
convertible driven by an absent-minded academic. Crawling along
in the fast lane on I-78, Liepert tried, in a sturdy German
accent, to explain her research. “We try to see how much air
pollution is locally emitted and how much goes around the
world,” she said. To that end, she (and her colleague Steven
Chillrud, who was both afraid of heights and on vacation) had
been measuring particles and light transparency in the air
column over New York City in recent months. Liepert had been
analyzing climate satellite data for NASA, but she wanted to
gather more nuanced information. “Within a balloon, you are part
of the air,” she said. This was her eighth