If alien terraforming emits greenhouse gases, our telescopes could detect it

Four side by side images of an earth-like planet in outer space.

If aliens were blanketing their planets with powerful greenhouse gases, as we do, we might notice. This is evident from a recent thought experiment in which scientists identified five “artificial” greenhouse gases that, if abundant enough, could be found in the atmosphere of certain areas. exoplanets using existing technology, including the James Webb Space Telescope … Read more