Close encounters of the “light” kind

• Jennifer J. Birriel ^[1]
  1. [1] Morehead State University

     Morehead State University

     Estados Unidos

     
• Localización: The Physics Teacher, ISSN 0031-921X, Vol. 63, Nº. 1, 2025, págs. 78-78
• Idioma: inglés
• Enlaces
  • Texto completo
• Resumen

  • This might look like an alien ship in the night sky, but the explanation is much more down to Earth. The yellow is sky glow produced by clouds reflecting high-pressure sodium (HPS) lamps used at App Harvest greenhouse near Morehead in Appalachia, KY. The white dots below the yellow sky glow are street and house lights. The greenhouse “supplements” sunlight with HPS lamps, especially during the winter months. The angular width of this feature is about 5°. This picture is taken at a distance of 3 miles from the greenhouse at 4:45 a.m. on November 16, 2024.