The land glows amber on all sides, and over the water another rainbow is forming.

The presence of rain indicates that Titan may be the only celestial body other than Earth upon which rainbows could form.

Moisture was so finely distributed that no rainbow could form.

With its thick atmosphere and methane rain, Titan is the only celestial body other than Earth upon which rainbows could form.

Up at the far end of Union Street a rainbow had formed against the lowering clouds.

The rainbow formed and Leviathan shuddered with sledgehammer force.

A magnificent rainbow formed the backdrop for the President as he posed for the phalanx of photographers who still record his every public move.

A rainbow slowly formed over the docks.

A distant rainbow formed a delicately coloured arc.

Who worked out how rainbows form?