Leamington’s Greenhouse Boom Lights Up the Night Sky

NASA’s Earth Observatory uses Landsat 8 imagery to show Leamington, Ontario, expanding to about 8 square kilometers of greenhouses—the largest concentration in North America—producing year-round LED-lit glows visible at distances of tens of kilometers. A 2022 bylaw requires light-blocking curtains to reduce night-sky brightness, and studies indicate these curtains help when properly deployed, though cloud cover and the Moon still affect brightness. The growing glow also intersects with ecological concerns for migratory birds near Point Pelee.