Why haven’t we found evidence of life anywhere but Earth? A trio of astrophysicists has revisited this question by taking a closer look at the “needle in a haystack” analogy. Their analysis involved creating a model to assess the amount of work that has been done searching for extraterrestrial life, the Search for Extra-terrestrial Intelligence (SETI) project, compared to how much is required before scientists can rule out the possibility that there is none. Jason Wright, Shubham Kanodia and Emily Lubar have written a paper describing their efforts and uploaded it to the arXiv preprint server.