Prompt: Extraterrestrial

Aliens Exist

While I do not believe that aliens have visited Earth, at least not during the existence of humans, I do believe they exist. There are billions upon billions of cubic light-years in the universe. It may be bigger. Just for clarification, one light-year is almost 6 trillion miles. That is 63,000 times the distance between the Earth and the Sun. There are close to 2 trillion galaxies in the universe. Each of those contain a notable number of solar systems, each of which hold several planets. I find it to be extraordinary doubtful that Earth is the only planet out all several quadrillion planets on which life has ever existed. We have, in 60 years, found 24 planets that appear to be better suited for life than Earth. While that may not sound like much, keep in mind that it is 24 planets out of the few we’ve investigated. We’ve searched at most a few thousand planets for life, and over 24 of those could have it. There are several criteria for life. There must be liquid water, a very particular type of atmosphere, light and chemical energy, and the ability to replenish resources. These criteria are common enough, and they are based on Earth. Some of them may not be necessary. They also only look at carbon-based life. There could be different types. Overall, it is very unlikely that aliens do not exist, no matter if they’ve visited Earth.