Why are Starlink satellites visible as a line in the sky when the ground below is dark?
Answer
They are high enough to still be illuminated by the sun.
Starlink satellites do not produce their own light; they become visible because they remain high enough in the atmosphere to catch the sun's illumination even after sunset or before sunrise on the ground.
Related Questions
What specific formation are observers witnessing when they report a crisp, white line shortly after a Starlink deployment?Why are Starlink satellites visible as a line in the sky when the ground below is dark?During what precise time window are Starlink satellite trains overwhelmingly reported?What is a defining characteristic of a Starlink train's movement that helps distinguish it from a meteor?How do the lights of a Starlink train typically differ from those of a conventional aircraft?What is the primary design purpose of SpaceX’s Starlink satellite constellation?What program has SpaceX introduced specifically to reduce the brightness of their satellites in lower orbits?What unique dependency dictates the visibility window for a newly deployed Starlink train?If an observer captures an incredibly bright, wide glow across the sky with a camera, what might this artifact represent?What two key pieces of information are generally required to confirm a sighting using online satellite tracking tools?