prompter: Are there any signs of alien life out there?

assistant: Well, there is no definitive answer to whether there are any signs of alien life out there, but many scientists are optimistic that we will find some evidence in the near future. According to NASA's chief scientist Ellen Stofan, "I think we're going to have strong indications of life beyond Earth within a decade, and I think we're going to have definitive evidence within 20 to 30 years."

Some of the possible ways to look for signs of alien life include searching for water and organic molecules on other planets and moons in our solar system, detecting radio signals or other signs of technology from distant civilizations, and analyzing the atmospheres of exoplanets for biosignatures such as oxygen or methane.

One intriguing example of a potential sign of alien life is 'Oumuamua, a mysterious object that visited our solar system in 2017. Some astrophysicists, such as Avi Loeb from Harvard University, have suggested that 'Oumuamua could be a piece of extraterrestrial technology or debris from a distant star system.

However, these hypotheses are not widely accepted by the scientific community and require more evidence and investigation. The search for alien life is an ongoing and exciting endeavor that may reveal surprising discoveries in the future.

If you want to learn more about this topic, you can ask me more questions or visit some of these websites:

- [NASA - Search for Life](https://www.nasa.gov/topics/search-for-life/index.html)
- [SETI Institute - Home](https://seti.org/)
- [BBC Science Focus Magazine - New issue: Signs of alien life](https://www.sciencefocus.com/magazine/new-issue-signs-of-alien-life/)

assistant: Not yet but scientists are doing their best to capture and interpret potential signs every day. Statistical probability, based on our current understandings, states that we should expect some kind of alien life in the universe. Truth is out there, still. :)

assistant: It is hard to determine if we have detected signs of alien life yet as the tools we currently use for astrobiology are limited.  What actually is life? It’s getting increasingly complicated to come up with an answer that takes in all the “lifeforms” discovered and that might have once existed on our planet. One frequently used definition of life is “a self-sustaining system capable of Darwinian evolution.” But there are literally several hundred more.

Ironically, some astrobiologists argue that we really won’t know what life is until we find an alternative to the basic structure found on Earth – the same DNA, metabolism and carbon-based blueprint shared by all known life. In other words, ET life could tell us what life really is.

A corollary to this line of thinking is the ever-present concern that a rover or lander has, or will, come across an example or signature of life present or past and not know it. This reality helps explain the emphasis that astrobiology puts on understanding the origins and logic of early life on Earth. In addition to its inherent importance, origin-of-life research guides the search for extraterrestrial life.

As yet we have not discovered unambiguous signs of life on other planets, but this could also be due in part to the need for new telescopes, processing data from SETI and the return of samples from Mars.