Explanations for UFO sightings

2008-05-16 12:59

London - Here are 10 possible explanations for UFO sightings:

Weather balloons - Gas-filled balloons that measure conditions in the upper atmosphere to help forecasters.

Clouds - Saucer-shaped clouds that form at high altitudes have been confused with UFOs.

Meteors - Space debris can create a spectacular lightshow when it burns through the Earth's atmosphere.

Civilian or military aircraft - Planes can look mysterious at night or in certain light conditions.

Ball or bead lightning - Strange forms of lightning that are rarely seen and are the subject of scientific debate.

Stars or planets - Heavenly bodies can be confused with UFOs.

Sundogs - Also called "mock suns", these are bright spots on the solar halo that appear as balls of light in the sky.

Airships or advertising balloons - These can look like flying saucers from some angles, especially at night.

Mirages - A natural phenomenon where cold or hot air bends light rays to produce an image of a distant object in the sky.

Magnetic fields - A Ministry of Defence report said people exposed to certain electrical or magnetic fields can suffer from "vivid, but mainly incorrect" recurring memories.

- Reuters