How a discussion about the moon clock led to the emergence of a new clock for this world….What time is it on the moon?
This topic is far from new. In fact, it was first explored over half a century ago by a highly respected and well-known American astronomer!
Moreover, this astronomer didn’t just theorize about how to tell time on the Moon. He actually developed a methodology for it. Utilizing his calculations, a well-known watch company of that era even created a wristwatch that could accurately display lunar time at a glance.
The astronomer in question was Dr. Kenneth Franklin (1923-2007). He served as the Chief Scientist at the Hayden Planetarium in New York from 1956 to 1984. Dr. Franklin was a pioneering figure in astronomy, contributing to the discovery of radio emissions from Jupiter—a groundbreaking discovery as it marked the first detection of signals from another planet. His influence extended beyond his scientific work, as he became a prominent media figure both locally and nationally. He authored numerous technical papers and served as a consultant for Scientific American, The New York Times, NBC, and CBS. In addition, he contributed articles on astronomy to the World Book Encyclopedia.
lunar time zone
In 1970, during the height of the Apollo lunar landing program in the United States, Dr. Franklin devised a special formula to determine lunar time. During a press conference at the New York Press Club in April of that year, Dr. Franklin stated, “In the not-too-distant future, we will have permanent bases on the Moon, and the men operating these bases will need a timekeeping system that aligns with the position of the Sun. Therefore, we need a time system based on the Moon’s rotation.”
Of course, Dr. Franklin’s predictions in 1970 weren’t far from reality. The last real mission to the Moon was in December 1972, and at that time, these “permanent bases on the Moon” had not yet materialized. However, if today’s space scientists are correct, these lunar bases might finally become a reality.
لكن ماذا عن ساعة اليد؟ الوقت على القمر
Helbros Watches
The Story of the Lunar Timepiece From Earth to the Moon
Helbros, a watch company founded in 1913, was once a prominent name in the timekeeping industry. Located at 2 Park Avenue in New York, the company reached its peak during the 1950s. However, following the death of its founder, William Helbein, in 1960, Helbros gradually declined, eventually closing its doors by the mid-1970s.
But as the 1960s drew to a close, and with the world captivated by the Apollo Moon program, Helbros found an opportunity to reignite its brand. The company conceived a concept that could have rekindled enthusiasm and popularity for their watches. In the same April 1970 press conference where Dr. Franklin introduced his lunar timekeeping system, Helbros unveiled a prototype of a lunar wristwatch. This innovative watch was the brainchild of Ross C. Caskel, the company’s art director, who applied Dr. Franklin’s mathematical calculations to create it.
The lunar watch that was revealed was unlike any conventional watch people relied on here on Earth, primarily because it was based on the lunar month. As the Moon orbits the Earth, it also rotates on its axis, completing one rotation in the exact same time it takes to complete one orbit—an average of 29.530589 days as measured on Earth.
Dr. Franklin then divided the lunar cycle into 30 equal parts, which he called “luns,” each roughly equivalent to one Earth day. Each lun was further divided into 24 “luns” or long hours, each lasting about one Earth hour. However, instead of using minutes and seconds, the lunar time system employed a decimal system, breaking each lun into 100 “centes” and each cent into 10 “milliluns.”
ساعة فريدة من نوعها!
At first glance, the face of the Helbros moon watch might appear similar to that of a standard wristwatch,
but upon closer inspection, it reveals something entirely unique: the synchronized lunar time and the millilun.
While a typical watch here on Earth usually displays the day of the month in a window on the right side of the watch face,
the Helbros moon watch instead shows the lunar hours. According to the system developed by Dr. Franklin, the new moon corresponds to zero. The first quarter moon occurs at 7 luns and 12 moons. The full moon aligns with 15 luns, and the last quarter moon coincides with 22 luns and 12 moons.
Unfortunately, despite this innovative design, very few people knew about the lunar wristwatches manufactured and distributed
by Helbros at the time. It’s likely that this unique timepiece was regarded more as a novelty than as a useful scientific tool. Today, however, I am certain that the scientists who gathered last November in the Netherlands to discuss
timekeeping on the lunar system would be much more intrigued by this ingenious invention!