Extraterrestrial life refers to life that exists outside of Earth. This could include simple microbial organisms or advanced intelligent beings. Scientists search for extraterrestrial life through astrobiology, studying planets, moons, and exoplanets for conditions that could support life.
There is no scientific evidence that aliens exist, but they could come from other planets in the universe. The study of alien life is called astrobiology.
Yes, aliens could be harmful to humans. While it's impossible to know the intentions of any alien civilizations, many scientists believe that advanced aliens could destroy human civilization.
California has had the most reported UFO sightings in the United States, followed by Florida and Washington. However, when adjusted for population, the Western states have the highest rates of UFO sightings per capita.