Are aliens sending a message to Earth? NASA captured another strange and intriguing scenario in the Martian soil. Recent photographs show what appears to be Morse codes written on the sand dune fields.

The marks on the sand dunes look very similar to Morse codes. The Mars Reconnaissance Orbiter with the help of its innovative Hi-RISE camera used visible light and near-IR technology to capture the images. 

But experts from NASA say these dots and line marks that are visible on the red planet and had already appeared before. However, the codes from the recent photograph appear clearer due to the terrain in the Hagal Dune field just south of Mars' north polar cap. NASA calls the formation the "Martian Morse Code," but the agency also revealed that the formation this time around is extremely complex that it why it is very difficult for scientists to identify the direction of the wind. 

Scientists are still studying the causes of the unusual markings, but experts believe that these could be part of the normal Martian topography formed by winds and that circular depressions have "focused the wind, and also limited the amount of sand available for formation of the dunes," Veronica Bray, the Hi-RISE targeting specialist said in an interview with Gizmodo.

Although the code is very clear that if they were Morse codes, they can easily be deciphered by experts. But this sand behavior is very common that it can also be observed on Earth, according to Science Alert. Experts say these are carved out by the directions of the winds and that there are no alien activities involved in the formation of what looks like Morse codes sent by extraterrestrial beings to Earth-borne humans. But for sure, conspiracy theorists think otherwise.

The unusual movement of the wind can also result to form sand into a line while the dots are called "barchanoid dunes." Although not so unusual, the formation of the Morse code on the sand dunes still remains a mystery for scientists at NASA.