Mirage appearing as a layer of shimmering water on a hot road. This is a type of inferior mirage, which occurs when the air at the surface is significantly warmer than the air just above it. Cold air is denser and refracts light more, and the sharp temperature gradient has the effect of refracting upwards rays of light hitting the ground at a shallow angle from just above the horizon, giving the impression that the sky beyond the mirage is being reflected by a pool of water. Reflections of approaching cars are also seen beneath them. Filmed in Utah, USA.