While there is no concrete evidence of life beyond Earth, many scientists say the possibility is likely. Researchers continue to search for signs of extraterrestrial life by studying other planets and moons, particularly their atmospheres, in search of conditions that could support life. There's no telling what's out there, and, if aliens exist, they could range from creatures as simple as tiny organisms to other complex beings with technologically advanced civilizations. Explore our findings on aliens, from scientific research on the topic to famous accounts of claimed sightings.
Hours of research by our editors, distilled into minutes of clarity.
The Fermi paradox addresses this discrepancy between the lack of evidence of alien life despite the high likelihood of its existence. Physicist Brian Cox offers various theories, like the extinguished civilizations hypothesis, for why we have never found any extraterrestrial neighbors.
There's a chance that human civilization arrived before any other life and aliens will soon emerge. If this is the case, there's also a chance for a competition to rule the Universe.
Area 51 is a highly classified US military facility located in Nevada. Because of its remote location and secrecy, many Americans have speculated that the location hosts aliens. However, critics of this theory believe the UFO sightings are actually just military aircraft.
A 2019 Facebook event called on attendees to "Storm Area 51, They Can't Stop All of Us," spawning countless memes. Millions marked themselves as "going," and seven were arrested at a gate into the area. It also inspired a music festival attended by more than 7,000 people.
Humans tend to imagine aliens as humanlike, but that's probably unlikely. From small space spiders to metallic carnivores, life on other planets—and how we could interact with it—is difficult to imagine.
Housed aboard Voyager 1 and 2, each record serves as a time capsule of human culture and a peaceful introduction to any intelligent life. Even if never played, the records can outlast humanity and travel through space for a billion years.
The Golden Record holds what is essentially a human "time capsule," featuring music, nature sounds, and greetings from around the world. NASA used the radiation period of hydrogen's simplest transition as a baseline to convey timing and structure. The first coded image is included on the cover as a test so aliens can check if they decoded it correctly.
The hunt for extraterrestrial life is often associated with traveling far into the depths of space for clues. But answers could be closer than we think. Modern space missions have demonstrated our capability of sending probes beyond the solar system, making it plausible that other civilizations could do the same.
Given the vastness of the Universe, detecting alien life may require technological progress beyond the limits of what is sociologically viable and physically possible. Although interstellar civilizations are unlikely, messaging techniques and probes may improve the odds of successful communication with other intelligent life.
Researcher Zecharia Sitchin proposed that Sumerian cuneiform tablets revealed that Sumerian gods were aliens who landed on Earth in Mesopotamia and influenced the creation of modern humans. While his ideas gained cultural interest, they are widely rejected by mainstream scholars.