Space enthusiasts were left baffled after spotting an alleged UFO spacecraft hover near astronauts as they performed their spacewalk abroad the International Space Station (ISS) on Tuesday, according to a YouTube video uploaded by NASA.  Earlier reports in 2014 have also indicated sightings of UFO's visiting the habitable space station, Examiner reported.

In the live camera feed, the spacewalking astronauts are seen performing their mission when suddenly around the 1:50 minute mark, a mysterious craft appears and hovers for about a few seconds. In the foggy telecast, the shape and size of the elliptical UFO seems difficult to decipher.

Since the ISS is known to have visitors during its mission, the unknown object could have been one of two supply ships visiting the ISS. After a Space X Dragon cargo ship traveled to the ISS on Sept. 23, it was followed by a three-member Soyuz TMA-14M ship on Sep. 25.

"However, both craft are docked, and not floating near the ISS as the unknown object appears to doing in the Oct. 7 video," according to Examiner.

A different possible theory could be the ISS's camera reflection or lensflare.

"However, there does not appear to be any strong source of light near the astronauts or camera during the video segment when the UFO appears. The even light in the background of the video during the critical period appears to rule out a lensflare/camera reflection explanation," Examiner stated.

Meanwhile, a live video feed on January 29 featured the ISS being joined by a yellow-colored elliptical UFO, which eventually docked with the artificial satellite. Although the video raised speculations and various theories, NASA refrained from commenting on the unknown spacecraft.

Separately on Oct. 3, multiple sightings by individual witnesses and groups, including an investigative reporter, of three "shiny" UFO's in Breckenridge, Colo., prompted an investigation by a military defense command, according to KUSA-TV.

A similar incident involving "white dots" occurred in the Salt Lake City area just a day before, a Utah television station reported. Another report of "3 bright white lights in diagonal line" was posted by UFO Stalker on Oct. 2 from Taylorsville.