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. 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. Space Exploration Phys.org – latest science and technology news stories