McGregor has seen the objects several times in the past, with the most recent time being in January of 2011. He hopes that others who watch his video might be able to shed some light on the mystery. But McGregor’s theory is that the UFOs he has encountered are secret military aircraft.

Click below to watch McGregor’s UFO footage from 2006:

On January 20th, 2010, a large, disc-shaped cloud was videotaped over Indonesia. The formation appeared to be illuminated, and was positioned over a thick bed of clouds. An explanation formulated by meteorologists for this event was sunlight shining through a very high thundercloud.

Another disc-shaped cloud formation, outlined with an illuminated ring, was captured on video in the skies above Romania in October of 2009. Some witnesses described the cloud formation as resembling a craft. Again, meteorologists have formulated an explanation for this odd occurrence, calling the formation a fallstreak hole.

What is a fallstreak hole?

Sometimes, a lack of ice nucleation particles slows the freezing process of water in clouds where the temperature is below freezing. When this water does start to freeze, the water vapor around it freezes too, and begins falling to the earth. The often circular hole left in the cloud is known as a fallstreak hole.

View some examples of fallstreak holes.

Meteorologists have also used lenticular clouds to explain other UFO sightings. Lenticular clouds are high-altitude clouds that have a lens shape, and a smooth, saucer-like appearance. Some amazing examples can be seen here.

Another unusual cloud formation, referred to by the British tabloid The Sun as a “Mystery UFO Halo,” was observed over Moscow in October of 2009. This incident was also explained by meteorologists as a fallstreak hole. But not all meteorologists agree. Moscow’s weather bureau called the event an optical effect caused by sun shining through the clouds.

So what is the real explanation for these mysterious cloud formations? Meteorologists point to natural occurring weather behavior like fallstreak holes. But fallstreak holes rarely occur, so, have weather changes simply caused them to become more common now, or is there another explanation?

Could these objects have extra-terrestrial origins?

Are UFOs generating clouds for camouflage?

The photos and videos from the recent sightings don’t provide enough evidence to definitively determine the true nature of the abstruse objects, but they are certainly more than enough to fuel intrigue and extra-terrestrial speculation.