When does the sky become fully dark for stargazing?
Quick Answer: The sky becomes fully dark for stargazing during astronomical twilight, which starts when the sun is about 18 degrees below the horizon. At this point, the sky is dark enough that faint stars and deep sky objects become visible without interference from sunlight.
Astronomical twilight happens after sunset when the sun dips well below the horizon, but before the sky reaches complete night. This phase means the sun's light no longer brightens the sky enough to hide the dimmest stars.
Because the sun is 18 degrees below the horizon during astronomical twilight, sunlight scattering in the atmosphere is minimal. This makes the sky at its darkest and perfect for serious stargazing or astrophotography.
The exact time astronomical twilight begins depends on your location and the time of year. But once it starts, the sky is ready for you to enjoy the full beauty of the night sky.