Synopsis

The universe as we know it stretches across an immense expanse, existing for over thirteen billion years. Within its vastness, up to two trillion galaxies—each containing perhaps twenty sextillion stars—encircle our own Milky Way. Within the Milky Way alone, scientists estimate the presence of roughly forty billion Earth-like planets residing within the habitable zones of their stars. Faced with such figures, it seems improbable that we are alone.