The Hubble Space Telescope, which was launched into low Earth orbit more than two decades ago, has produced numerous images of cosmic objects in the past, many of which have provided scientists with insights about the universe.
Some of these photos are being ignored but a closer look could sometimes yield interesting sights. One particular image, for instance, is currently drawing attention after artist Judy Schmidt submitted a version of it to the Hubble's Hidden Treasures image processing competition.
The competition provides ordinary people with the opportunity to find iconic images taken by the Hubble that have not yet been seen by the public, images scientists behind the space telescope call as hidden treasures.
"Searching Hubble's archive for hidden treasures is a lot of fun, and it's pretty straightforward, even if you don't have advanced knowledge," reads the Hubble's Hidden Treasures page. "So we're inviting you to come and help us find iconic Hubble images that have never before been shown to the public."
The image Schmidt submitted shows what appear to be two orange eyes gleaning from what seemed to be a grinning face. The image is actually of a galaxy cluster known as SDSS J1038+4849 and the smile was the result of an effect called gravitational lensing, a phenomenon that can cause space and time to warp around objects given sufficient gravitational pull.
"You can make out its two orange eyes and white button nose. In the case of this 'happy face,' the two eyes are very bright galaxies and the misleading smile lines are actually arcs caused by an effect known as strong gravitational lensing," the European space agency said.
Big galaxy cluster, the most massive entities in the universe, at times produce strong gravitational pull that can warp time and space around them. In essence, gravity is comparable to the lenses in eyeglasses but it is so strong, it does not just magnify but also bend light. The National Aeronautics and Space Administration (NASA) noted that many of the discoveries made by Hubble became possible because of this lensing.
The circular face of the cosmic smiley is called an Einstein ring, which is produced by a special view of a warped galactic cluster. Albert Einstein's General Theory of Relativity proposed that gravity can bend light and such bending can produce an optical illusion now known as Einstein ring. The presence of two bright galaxies insides the ring is also perfectly positioned in a way they appear as eyes.