Astronaut Scott Kelly of the National Aeronautics and Space Administration (NASA) is known for sharing breathtaking photos of the Earth as seen from outer space, particularly from the International Space Station, using his Twitter account.

Last week, however, Kelly may have tweeted a photo of something that is more astounding and baffling—a possible unidentified flying object hovering over our planet.

In his tweet, Kelly said "Day 233: Once upon a #star over Southern India. #GoodNight from @space_station! #YearInSpace"

The photo attached to the tweet showed the portion of the Earth over India glowing from outer space, but what Kelly captured at the upper right hand corner of his picture caught the attention of some people.

YouTube user Sonofmabarker, for instance, drew attention to the thing that looks like a "a large object with two lights on each end."

"It also appears to be very large and constructed. I would find it hard to believe that Scott Kelly did not notice this when he tweeted this out. It really sticks out like a sore thumb," the YouTube user said in a video he uploaded on the content-sharing site.

"Scott Kelly, thank you for sending this photo down to Earth. Hardly a week goes by without someone from the ISS sending us a photo or video that really is quite strange and it is left for us to decide," he added.

Scott C. Waring, editor of blog site UFOsightingsdaily.com, meanwhile described the image captured by Kelly as "a cigar-shaped glowing UFO with a metallic body in it."

"The UFO is about 25 meters long and 150 to 200 meters away. It looks like Scott was trying to hint at the existence of aliens. Message received Scott, and thanks," Waring said, as quoted by The Express.

"When an astronaut tweets a photo of a UFO, you can bet people notice it," he added.