The dark sky over an urban park in central Mexico attracts stargazers who worry it might not last
JOYA-LA BARRETA ECOLOGICAL PARK, Mexico — As night descended, a rumble of frogs filled the air in this park outside the central Mexican city of Queretaro. In the sky, tiny stars appeared one by one, aligning into constellations. Juan Carlos Hernández used his weight to adjust a large telescope. “Aim for me, Rich!” he yelled…