Alien lifeforms refer to any living organisms that may exist outside of Earth. These could range from simple microorganisms to complex beings, potentially found on other planets or moons within our solar system or beyond. Scientists search for signs of life by studying extreme environments on Earth, which may resemble conditions on other celestial bodies. The search for alien life often involves exploring places like Mars and the icy moons of Jupiter and Saturn. Missions such as the Mars Rover and the James Webb Space Telescope aim to gather data that could indicate the presence of life or the conditions necessary for it to thrive.