When it comes to finding objects on Mars, people can rely on alien theorists or UFOlogists to give us some interesting “discoveries.”

By combing through available photos regularly uploaded by NASA, some alien enthusiasts were able to see “animals” such as birds, monkeys, penguins and even pigs courtesy of pictures by the NASA Curiosity rover. This has led to some more photos resurfacing and encouraging people to believe that there might be life lurking around the Red Planet.

One of these photos is a picture released by the U.S. space agency back in 2016 which seemingly looks like the fossil of a fish. The image in question truly looks like a finned creature complete with a tail and an upturned mouth.

The image was initially pointed out by UFO Sightings Daily, a popular website which constantly releases odd shapes spotted from official NASA photos.

What’s interesting about the picture is that a fish fossil can easily be explained if it exists on Planet Mars. According to CNET, the Red Planet used to have vast oceans that are said to be even bigger than the Arctic back here on Earth. Of course, these bodies of water are now gone and what’s left is a red, dry and dusty planet wherein scientists hope they can still find any signs of ancient life.

The fossil, however, can only be regarded as a rock formation with the right lighting angle and shadow to make it seem like an actual fish. Now even if most of the objects are mere speculations, there are times when NASA tries to explain what people might be seeing.

In an earlier report by IBTimes regarding a supposed human thigh bone found on the Martian surface back in 2014, NASA explained: “Mars likely never had enough oxygen in its atmosphere and elsewhere to support more complex organisms. Thus, large fossils are not likely."

Finding odd shapes on the surface of Mars, or anywhere outside the Earth for that matter, actually has a scientific explanation. This “ability” is referenced to pareidolia or the tendency of the human brain to catch meaningful patterns in various images.

“Pareidolia is a normal neuro perceptual phenomenon. It happens in auditory and tactile domains as well … [pareidolia] helps us to be super alert to things … and thus is evolutionarily advantageous,” Dr. Kang Lee, a neuroscientist from the University of Toronto, said.

An image of Mars' Nili Fossae region taken by NASA's Mars Reconnaissance Orbiter. NASA/Christopher Kremer/Brown University