Our search for technosignatures - clear signs of advanced civilizations beyond Earth - takes many forms. Many are driven by the famous Drake equation, which attempts to estimate how many technological civilizations there are in the Milky Way. However, theres a big fat question mark at the end of that equation in the form of a variable intended to account for the longevity of a civilization. And to be clear, that doesnt mean how long the civilization itself survives. It simply means how long it actively creates a signature that is detectable by our current technology. A new paper, available in pre-print on arXiv from Oxford astrophysicist Brian C. Lacki, argues that, since the chances of us overlapping in time with any such civilization are miniscule, were much more likely to find the ruins of a dead civilization - and, surprisingly, the best place to do so might be in our own solar system.