This was
your sky.

A Filament Across the Sun

This long, light feature is a solar filament, a cloud of charged hydrogen gas held above the Sun's surface by its magnetic field. Unlike Earth clouds, which are water droplets, a solar filament is extremely hot. It appears dark against the Sun's bright face because it is cooler than the photosphere behind it. This filament, captured in a color-inverted image, stretched across the Sun.