SPACE
Moving air cells with different temperatures and densities continually bend a star's point-like light. Multiple paths from a planet's tiny disk average those fluctuations, making it look steadier.
Microgravity removes much of the load compressing the spine, letting discs expand and curves straighten slightly. Height can rise by up to about three percent before returning on Earth.
Fine Martian dust scatters blue light forward near the Sun's direction. The longer sunset path makes a blue halo stand out within the reddish sky.
Ordinary sound is a mechanical wave carried by particles. Vacuum lacks a dense medium for pressure waves, although electromagnetic signals can still cross it.
The Moon spins once during each orbit of Earth. Tidal forces gradually synchronized those two motions, creating the stable state called tidal locking.
Jupiter's Great Red Spot, a massive swirling storm, is larger than Earth's diameter and has been raging for hundreds of years without dying down.
Venus rotates in the opposite direction from most planets, so the Sun would appear to rise in the west and set in the east.
