Hidden signal: Venera 7's post-landing data becomes the first surface transmission from another planet

Ground stations initially treated Venera 7’s post-touchdown radio as noise, but engineers later recovered 22 minutes 58 seconds of data from the recording, proving the spacecraft survived impact and transmitted from Venus’s surface—the first transmission from another planet. The measurements indicated surface conditions around 475°C and 90 atmospheres, informing later Venus landers and mission design, and showing that the “first” surface transmission was buried in the recording rather than immediately observable.