UFO hunters are speculating about the presence of an 'alien megastructure,' after a mysterious triangular object was seen hovering in the night sky in Melbourne, Australia.

The UFO was recorded by YouTube user UFO Lou, according to Inquisitr, and was spotted in the sky on November 13.

The appearance lasted under two minutes, but has spurred a conversation among the YouTube community about what may have been up there.

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Many YouTube users expressed ideas that this may have been an incidence of sudden 'uncloaking,' referring to the idea that aliens camouflage their space crafts by simulating the clouds

RULING OUT AN ALIEN STRUCTURE In order to explore the idea that such a structure could have been built by intelligent alien life, the Extraterrestrial Intelligence Institute, Seti, trained its Allen Telescope Array on the star for more than two weeks. Experts looked for two types of radio signal: narrow-band signals generated as a 'hailing signal' for alien societies wanting to announce their presence, and broad-band signals. These signals would be produced by 'beamed propulsion'. Seti said that if large scale alien engineering projects really are underway, the array would pick up signals made by intense microwave beams that could be used to power spacecraft. Scientists analysing the data found no clear evidence for either type of signal. Advertisement

'Never seen anything like this before,' writes UFO Lou.

'Object seems static. Simply appears, lasts a few minutes, and then vanishes. Massive in size. Using a 50mm lens.'

In the video, the object can be seen coming slowly into view, starting first as a faint shadow and then becoming solid over a span of about 15 seconds.

A moment after the object becomes clearest, it suddenly vanishes.

While UFO Lou says the object may be an optical phenomenon, caused by 'some kind of reflection,' other YouTube users contributed their ideas about what may have been lurking in the sky.

Many expressed ideas that this may have been an incidence of sudden 'uncloaking,' referring to the idea that aliens camouflage their space crafts by simulating the clouds.

'Wow. Someone [leaned] on the 'uncloak' button it seems. Awesome catch Lou,' writes a user.

Comments on the page, with varying levels of enthusiasm, support the theory that UFO Lou has captured a moment of brief uncloaking.

'OH YEAH!!!! There is is…there it is not,' another user writes. 'Raise the cloaking device Scotty!' Love this footage…. A LOT!'

In the video, the object can be seen coming slowly into view, starting first as a faint shadow and then becoming solid over a span of about 15 seconds

'Craft showing cloaking technology, most probably interdimensional,' another user writes.

In October, NASA's Kepler Space Telescope captured mysterious footage of strange fluctuations in starlight, which prompted theories of an alien megastructure.

NASA has ruled out extraterrestrial causes, and say structure was likely a natural phenomenon.

UFO Sightings Daily editor Scott Waring also thinks the mysterious triangle may be a UFO, according to Inquisitr. Waring has reported seeing an alien megastructure using Google Sky.

UFO Sightings Daily editor Scott Waring also thinks the mysterious triangle may be a UFO, according to Inquisitr. Waring has reported seeing an alien megastructure using Google Sky

In October, NASA's Kepler Space Telescope captured mysterious footage of strange fluctuations in starlight, which prompted theories of an alien megastructure

An alien megastructure, Waring says, is an artificially constructed space station consisting of well-formed cubes. He says his sighting is a megastructure that is bigger than Earth's moon.

Despite speculation, Search for Extraterrestrial Intelligence (SETI) reported that it studied the area using the Allen Telescop Array (ATA) and did not find any evidence that suggests intelligent life.