The Milky Way in the morning twilight over the Yellowstone National Park, a World Heritage Site in Wyoming, USA. The three bright stars of the Summer Triangle (Vega, Altair, and Deneb) are at the upper left. On the Earth is a geothermal pool of a hot spring. Established in 1872 the Yellowstone is the world's earliest national park, known for its wildlife and geothermal features.