Anders - who was a lunar module pilot on the Apollo 8 mission - took the iconic Earthrise photograph, one of the most memorable and inspirational images of Earth from space.

Taken on Christmas Eve during the 1968 mission, the first crewed space flight to leave Earth and reach the Moon, the picture shows the planet rising above the horizon from the barren lunar surface.

Anders later described it as his most significant contribution to the space programme.

The image is widely credited with motivating the global environmental movement and leading to the creation of Earth Day, an annual event to promote activism and awareness of caring for the planet.

Speaking of the moment, Anders said: "We came all this way to explore the Moon, and the most important thing that we discovered was the Earth."

Simultaneity Ain't what It Used to Be

One of the most fundamental deductions Albert Einstein made from the finite speed of light in his theory of special relativity is the relativity of simultaneity—because light takes a finite time to traverse a distance in space, it is not possible to define simultaneity with respect to a universal clock shared by all observers. In fact, purely due to their locations in space, two observers may disagree about the order in which two spatially separated events occurred. It is only because the speed of light is so great compared to distances we are familiar with in everyday life that this effect seems unfamiliar to us. Note that the relativity of simultaneity can be purely due to the finite speed of light; while it is usually discussed in conjunction with special relativity and moving observers, it can be observed in situations where none of the other relativistic effects are present. The following animation demonstrates the effect. //

... by extracting transmissions from the LM from those originating in mission control onto separate tracks with the Audacity audio editor, I was then able to time-shift transmissions originating from the Earth by the light delay of 1.2865 seconds to reproduce what Buzz Aldrin and Neil Armstrong heard through their headphones in the cabin of the Eagle lunar module on the surface in Mare Tranquillitatis. During the landing phase, an on-board tape recorder in the lunar module captured the voices of Armstrong and Aldrin even when they were not transmitting on the air to ground link. From this noisy source, I have restored the few remarks by Armstrong which were only heard within the cabin. This is, then, the lunar touchdown as heard by the astronauts who performed it.

Now it's obvious what happened to Armstrong's post-landing transmission! Right before he began the call, Duke's message, sent a second and a quarter earlier, arrived at the Moon. While, from an earthly perspective, this was spoken well before Armstrong said “Houston”, on the Moon this message “stepped on” the start of Armstrong's transmission (especially considering human reaction time), and caused him to pause before continuing with his message. Note also that on the Earth-based recording, Duke's response occurs almost immediately after the end of Armstrong's transmission, but on the Moon, the astronauts had to wait for the pokey photons to make it from the home planet to their high gain antenna on its distant satellite.

This image (click on image to enlarge) shows the sequence of images that were read out during what is termed “priority” readout vs the “final readout”. The priority readout was an opportunistic scanning of processed photos on the lunar orbiter before all of the images were taken. The photo process with the 70mm film began with an image being simultaneously taken by the 610 mm high resolution camera and by the 80 mm medium resolution camera. In a process remarkably similar to the old polaroid dry process instamatic cameras, the film was dry processed by a “bimat” dry processor. The bimat would separate from the film (most of the time) but would sometimes due to the timing would leave artifacts on the image, which are readily identified on the film.

The film would then be fed into the readout looper where it could be scanned and the images sent back to the Earth. During the mission when photographs were still being taken the film would run one direction through the looper. After all of the images were taken a command would be sent to cut the bimat and then the film could be read in the opposite direction.

Thus when we start with a low numbered tape, the first images that come off are from the priority readout in ascending order. However, the ascending order is not linear, jumping because images are still being taken and the film advancing while the spacecraft cannot transmit.

At 12.56 pm on 21 July 1969 Australian Eastern Standard Time (AEST), mankind took its 'one giant leap' and 600 million people watched as Neil Armstrong walked on the Moon.

Our Parkes radio telescope, Murriyang, famously supported receiving the television signals on that momentous day. Although many people think the Parkes telescope was the only station receiving the signal, it was the 26-metre antenna at NASA's Honeysuckle Creek space tracking station near Canberra that was the prime station assigned with receiving the initial TV pictures from the Moon and Neil Armstrong's first steps on the lunar surface. (The Tidbinbillla deep space tracking station, today known as the Canberra Deep Space Communication Complex, provided support to the command module in lunar orbit.)

Eight and a half minutes after those first historic images were broadcast around the world, the television signal being received by the larger 64-metre Parkes radio telescope, Murriyang, was then selected by NASA to provide the images for the following two hours and 12 minutes of live broadcast as the Apollo 11 astronauts explored the Moon surface.

“I’ve spent the past week in Mountain View, California, hanging out with a group of Lunar Orbiter Image Recovery Project (LOIRP) hackers who are working out of an abandoned McDonald’s on the NASA Ames base. For more than five years, LOIRP technologists (or techno-archeologists, as they prefer to be called) have been reverse-engineering analog tape drives and developing new software in an attempt to unearth some of the first images of the moon that were taken by unmanned lunar orbiters in advance of the manned Apollo missions of the late 1960s. Upon entering the building (affectionately called “McMoon’s” by those who work within it) for the first time, I was greeted by familiar architecture. The drive-thru windows, menu light boxes, stainless steel counters, fiber glass tables and the ghosts of corporate brand ephemera all remain. However now they coexist under a jolly roger with a literal mountain of vintage 2-inch tape reels that contain trapped data, refrigerator-sized Ampex tape drives, an army of Mac workstations and a seemingly endless supply of analog tape decks, monitors, cables and soldering supplies.”

Vigilant migration of data as new storage techniques become available is the only way to assure long-term preservation. Even if the IRIG tapes are found, we are almost at the point where the tapes would be un-decipherable. I think one of my machines could play them (I say think as I’ve never tested it to full 500 kHz bandwidth), but I don’t have the specialized video decoder. NASA apparently preserved some equipment should the tapes ever show up.

This also raises another spectre. We MUST be selective as to what we keep in our archives because if we keep everything we won’t be able to afford it–or find it. This is one of the key jobs that archivists do. However, blindly following retention practices, as was done by NASA for the IRIG Apollo 11 tapes, needs to be tempered by historians as well. Certain small subsets of data (moonwalk slow scan video) are much more important than others (astronauts’ blood pressure and other biometrics throughout the entire flight).

All organizations who keep archives need to address this. In a generation (or less) if we save everything, it will become an overwhelming burden and the high points will be lost if they are not properly indexed.

Here’s a very 1960s data visualization of just how much code they wrote—this is Margaret Hamilton, director of software engineering for the project, standing next to a stack of paper containing the software: //

As enormous and successful as Burkey’s project has been, however, the code itself remained somewhat obscure to many of today’s software developers. That was until last Thursday (July 7), when former NASA intern Chris Garry uploaded the software in its entirety to GitHub, //

But as the always-sharp joke detectives in Reddit’s r/ProgrammerHumor section found, many of the comments in the AGC code go beyond boring explanations of the software itself. They’re full of light-hearted jokes and messages, and very 1960s references.

One of the source code files, for example, is called
BURN_BABY_BURN--MASTER_IGNITION_ROUTINE

            TC      BANKCALL        # TEMPORARY, I HOPE HOPE HOPE