Nautical twilight

{
  "id": "MLC-T-MET-001826",
  "term": "Nautical twilight",
  "field": "Meteorology and atmospheric science",
  "definitions": [
    "The period of twilight when the center of the sun is between 6 and 12 degrees below the horizon. During this time, the horizon is visible, allowing for celestial navigation using prominent stars and planets. It occurs after civil twilight in the evening and before civil twilight in the morning.",
    "The time after civil twilight, when the brighter stars used for celestial navigation have appeared and the horizon may still be seen. It ends when the center of the sun is 12 degrees below the horizon, and it is too difficult to perceive the horizon, preventing accurate sighting of stars."
  ],
  "references": [
    "NWS Glossary"
  ],
  "url": "https://mlchart.com/terminology/meteorology/nautical-twilight/"
}