In the September issue, David L. Chandler describes how the hunt for extraterrestrials in the universe has changed in the past few decades in “The new search for alien intelligence.” The article describes how other life-forms on distant planets might unintentionally communicate with us, but 40 years ago, talks of ET were just as much as how we might communicate with them.
Astronomy magazine subscribers can read the full article for free. Just make sure you're registered with the website.