London : A black mark, being interpreted as a UFO, was recently spotted in Antarctica, triggering speculation that aliens might have landed on Earth. Russian researcher Valetin Degterev said that he spotted the mark “amongst the endless ice desert” while using Google Earth, adding that it looked like a UFO “in its most classic shape” stuck in the ice after crash landing three years ago, reported the Mirror. Degterev insisted that the unknown object, which measured about 65ft by 230ft, could not be explained by anything natural to the earth. However, he had apparently ignored many other cliff formations and shadows in the area. Meanwhile, Antarctic experts have said the black mark was a crevasse.