A habitable planet around a tidally locked red dwarf would likely have a very unusual sky: one side of the world would see the star fixed in place, huge and bright, while the opposite side would live under permanent night. Near the boundary between day and night, the star would sit low on the horizon forever, creating a long twilight band rather than a normal sunrise-sunset cycle.

What the sky would look like

  • Day side: the star could appear much larger than the Sun does from Earth because the planet must orbit very close to stay warm enough for liquid water.
  • Night side: the sky would be mostly dark, but not necessarily empty; if the planet has an atmosphere, heat and light can scatter enough to create faint glow and moving cloud patterns.
  • Terminator zone: the “permanent sunset” region could have the most Earth-like sky, with a steady dim red-orange light and long shadows.

Color and light

Red dwarfs emit a lot of their energy in infrared, so the daylight could feel dimmer and redder to human eyes even if the planet is still receiving usable energy. The overall sky color would depend heavily on the atmosphere, but it would probably not look like Earth’s blue sky unless the atmosphere scattered light in a similar way.

Weather and clouds

If the planet has a substantial atmosphere or oceans, winds could carry heat from the hot side to the cold side, softening the temperature extremes. That can produce dramatic cloud systems, especially near the night side, where models suggest thick clouds may form and shape the world’s visible brightness.

Simple picture

Imagine a world where the “sun” never moves: one hemisphere baked in a fixed glow, one hemisphere in endless night, and a narrow ring in between that sees a forever-setting star. That is probably the most striking sky effect of a habitable tidally locked red-dwarf planet.

TL;DR

The sky would likely be dominated by a motionless red dwarf, with permanent day on one side, permanent night on the other, and a twilight belt in between. With an atmosphere, the planet could still have clouds, wind, and habitable temperatures, but the sky would feel much stranger than Earth’s.