Scientists warn that current search methods may produce false negatives by failing to recognize alien biosignatures.

We might be looking directly at alien life and simply not seeing it. A study published in Nature Astronomy highlights the danger of false negatives in astrobiology. Our current technology and narrow assumptions about what life should look like might cause us to overlook genuine signs of biology. If an alien organism uses a different chemical toolkit, our sensors could easily miss it. We must learn how to recognize the unexpected.