The glowing arc of the Milky Way points to the great ruins of the Incan Empire, Machu Picchu, in this vivid night sky image.
Thomas O'Brien took this photo in early July 2013 from the summit of Putucusi Mountain, which is located across the Urubamba River Valley from the historic sanctuary of Machu Picchu, Peru. The UNESCO World Heritage Site is the dark, saddle-shaped area between mountains on the right side of the image where the arc of the Milky Way intersects with the horizon.
The Milky Way, our own galaxy containing the solar system, is a barred spiral galaxy with roughly 400 billion stars. The stars, along with gas and dust, appear like a band of light in the sky from Earth. The galaxy stretches between 100,000 to 120,000 light-years in diameter.