THIS ARTICLE IS republished from The Conversation under a Creative Commons license.
How much do we really know about what else is out there in the universe?
Let’s take an outlandish example. If there were aliens flying around our galaxy with the sort of warp drive technology we often see in sci-fi shows, what would the signal from their ships look like? Perhaps, surprisingly, our research shows we have the tools to answer this question, regardless of whether such things really exist.
Telescopes that use light to probe space can now see almost to