Extraterrestrial beings, often referred to as aliens, are hypothetical life forms that originate from outside Earth. Scientists and researchers explore the possibility of their existence through various means, including the study of Mars, Europa, and other celestial bodies that may harbor life. The search for extraterrestrial intelligence (SETI) involves monitoring signals from space for signs of advanced civilizations. Many people imagine extraterrestrial beings as humanoid creatures, but they could take many forms, depending on their environment and evolutionary history. The concept of extraterrestrial life raises questions about the universe's diversity and the potential for life beyond our planet, inspiring both scientific inquiry and popular culture, such as movies and books.