Footnotes

During this remarkable manoeuvre, the two spacecraft were initially docked, with the tether secured during Buzz Aldrin's umbilical EVA. After undocking, they pitched to a vertical stable attitude and extended the tether. As the spacecraft settled into their orbital motion, Gemini XII successfully demonstrated gravity-gradient stabilization, holding its orientation for approximately 90 minutes with all control systems turned off. This groundbreaking experiment proved the potential for station-keeping with minimal fuel use—a concept that would later be crucial for future space stations and long-duration spaceflight.

The photograph was taken by Buzz Aldrin looking south with the Hasselblad Super Wide camera and its 38mm lens.

[Original NASA caption for the photograph]
The Gulf of California area as seen from the Gemini XII spacecraft during its 30th revolution of Earth. Baja California Sur is the peninsula on the right. At lower left is the mainland of Mexico. A 100-foot tether line connects the Agena Target Docking Vehicle with the Gemini XII spacecraft.

From the mission transcript when the photograph was taken:

047:42:01 Lovell: We're in perfect shape. It's just beautiful and just perpendicular. If we only had a control system, I'm sure we could do this much better than even in the simulator.
047:42:12 Capcom (Mission Control): Yes. We're showing you're hanging in pretty good in pitch and yaw. [...]
047:42:45 Capcom: Okay. What we'd like to have you do, if you're willing, is just to let the roll go and see if it will damp out after a while here. [...]
047:43:11 Lovell: As long as that tether doesn't wrap around us, we'll do it.
047:43:16 Capcom: Okay.
047:43:18 Capcom: Flight doesn't really think you'll damp out in roll.
047:43:24 Aldrin: Well, we've stayed well above him now for quite a while. We're out in front of him just a little bit.

Literature
Earth Photographs from Gemini VI through XII, (NASA SP-171), 1968, p. 3