The United States government has shared many cases about Unidentified Anomalous Phenomena (UAPs) from the 1940s until today. This has led some people to think aliens are visiting Earth. In Australia, the US, and other places, about one-third of people believe this.
Scientists think aliens might exist, but there are three reasons why they are likely not visiting us. First, space is very large. The nearest star is about 40 trillion kilometres away. With current technology, it would take over 6,650 years to reach it. Our fastest spacecraft goes much slower than light.
Second, travelling to other stars would need a lot of energy. If a spaceship travels near light speed, it would need infinite energy, which is impossible. There are also particles in space that can be dangerous for any spaceship.
Third, Earth has a unique environment. Life here developed with oxygen, but oxygen can be harmful to aliens. They would need special suits, but many reports of aliens do not mention them.
Scientists continue to search for signs of life elsewhere in the universe. So far, they have found thousands of planets but no proof of aliens.
