Sign up for CNN’s Wonder Theory science newsletter. Explore the universe with news on fascinating discoveries, scientific advancements and more.
For centuries, a setting sun has signaled the end of fasting rituals on holidays such as Ramadan and Yom Kippur, a cue to tuck into a delicious meal after a full day of abstaining from food and drink. But what if the sun’s clockwork were to suddenly change, as it does for astronauts riding aboard the International Space Station? The orbiting laboratory whips around the Earth at about 17,000 miles per hour (27,600 kilometers per hour), giving passengers 16 sunrises and sunsets each day.
It’s a question astronaut Sultan Alneyadi has been contending with since his arrival at the space station on March 3. He’s one of fewer than a dozen Muslim astronauts who have traveled to space, and at the end of his mission in about five months, he will have been the first astronaut from the United Arab Emirates to complete a long-duration stay on the floating laboratory.
During his stay, Muslims on Earth will observe the month of Ramadan — a time of fasting, prayer and reflection that runs from the evening of March 22 to April 21. There will also be two Muslim festivals — Eid al-Fitr, which marks the end of Ramadan, and Eid al-Adha, a celebration of the annual pilgrimage that Muslims make to Mecca, the holy land in Saudi Arabia, that begins June 28.
“Six months is a long duration for a mission, which is a great responsibility,” Alneyadi told reporters during a January news conference.
But, as Alneyadi explained, as an astronaut he fits the definition of a “traveler,” excusing him from attempting to observe Ramadan at the same time as Earth-bound Muslims. “We can actually break fast,” he said. “It’s not compulsory.”
He added, “Fasting is not compulsory if you’re feeling not well. So in that regard — anything that can jeopardize the mission or maybe put the crew member at risk — we’re actually allowed to to eat sufficient food to prevent any escalation of lack of food or nutrition or hydration,” he said.
Alneyadi also told reporters during a news conference in Dubai in February that he could fast according to Greenwich Mean Time, or Coordinated Universal Time, which is used as the official time zone on the space station.
“If we had the opportunity, definitely Ramadan is a good occasion to fast, and it’s actually healthy,” Alneyadi added to reporters at his January news conference. “We’ll wait and see how it goes.”
Religion in space: A history
Astronauts and religious leaders have attempted to imbue extraterrestrial pursuits with spiritual significance from the earliest days of spaceflight.
During NASA’s Apollo 8 mission in 1968, the astronauts conducted a reading of Genesis, the first book of the Bible, on their way to orbit the moon. Buzz Aldrin, who was with Neil Armstrong during the first moon landing in 1969, also quietly took communion from the Eagle lunar lander — taking a sip of wine and a bite of bread blessed by his Presbyterian minister back in Houston — just before the men took humanity’s first steps on the moon.
In 2007, Malaysian astronaut Sheikh Muszaphar Shukor became the first practicing Muslim to stay on the International Space Station, and the Islamic National Fatwa Council of Malaysia issued special guidelines specifically to guide his and other future Muslim astronauts’ practices.
Although his flight coincided with Ramadan, the council said his fasting could be postponed until he returned to Earth or he could fast in accordance with the time zone of the place from which he had launched. He was also relieved of the obligation to attempt to kneel while praying — a difficult feat in zero gravity. And attempting to face toward Mecca, as Muslims must during Salah, or daily prayer, was left up to his best abilities, per the Fatwa Council guidelines.
Jewish scholars have proposed similar ideas. Not all Jewish astronauts have attempted to observe Shabbat, the Jewish day of rest, which falls on Saturday, during which Jews are supposed to refrain from all work activity. But Israeli astronaut Ilan Ramon did attempt it in 2003, when he flew aboard a Space Shuttle Columbia mission and, in keeping with advice from “leading rabbinical experts,” he observed Shabbat in accordance with Cape Canaveral, Florida, time, the place from which he had launched. Ramon and his six crewmates died when the Columbia orbiter broke apart during their return to Earth on February 1, 2003.
Among the other religious observances that have taken place on board the 20-year-old space station are annual Christmas celebrations and the Jewish holidays of Passover and Hanukkah — including a memorable 1993 episode in which NASA astronaut Jeffrey Hoffman broadcast himself spinning a dreidel in microgravity on national television.
“It’s a little game — a dreidel — and it’s something that you spin, and then you see which side comes up. And according to that, you either win or lose and I was just trying to see how you might reinterpret the rules for spaceflight since there’s no up or down,” he explained to the camera.
Observing Yom Kippur in orbit
As far as what theology says about how Jewish astronauts should observe Yom Kippur in space, there have not been any formal directives and — in fact — the concept has sparked disagreements among some rabbis and religious scholars.
For centuries, rabbis have grappled with the dilemma of how to celebrate timely holidays when the sun and the moon aren’t adhering to the norms that most humans are familiar with. A 2002 responsum, or a rabbi’s written response to a question about Jewish law, from Rabbi David Golinkin, president emeritus of the Schechter Institute of Jewish Studies in Jerusalem, reviewed some of the various arguments.
A rabbi from the 18th century, Jacob Emden, was naturally not familiar with space travel. However he was familiar with the concept of traveling so close to the Earth’s North or South Pole that a traveler might not see a sunset for months. His resolution was to simply count “days” as one normally would at lower latitudes, by marking the passage of 24 hours. Another rabbi from the 19th century, Israel Lifshitz, stated that if a traveler has a watch that shows the time at their point of origin, they should observe holidays according to that time, according to Golinkin’s responsum.
Faced with the modern-day issue of space travel, Golinkin wrote that NASA astronauts should set their watches to the US Central Time Zone followed in Houston, since that is where most US astronauts are based.
The question of how to celebrate Jewish holidays in orbit again arose when Jared Isaacman, a billionaire who funded a spaceflight for himself and three crewmates in 2021, climbed aboard a SpaceX Crew Dragon and became the first space tourist to fly to orbit from US soil. At the time, he told CNN that, although he is Jewish, he didn’t plan to observe Yom Kippur, which began at sundown the day of his launch in 2021.
“To be very honest, I’m actually not a religious person,” he said, acknowledging that he has been a contributor to a local synagogue in New Jersey.
On the other hand, Rabbi Dovid Heber, writing for kosher certification organization Star-K in 2007, simply said that “ideally, one should not travel to outer space.” But, “if one must go,” there are a number of different options that would satisfy the religious requirements. Heber does note, however, that it is theoretically possible to stretch what should be a one-day holiday into three days, depending on exactly where the spacecraft’s orbit lies.
The rabbi of the synagogue Isaacman has supported, Eli Kornfeld of Hunterdon, New Jersey, told CNN that he agreed with Golinkin’s assessment. If he were one day living in space, he would still observe Yom Kippur fasts in accordance with Earth-based clocks. Though, he added, he would probably do everything in his power to avoid being in space during such an important Jewish observance. On Yom Kippur, Jews are not supposed work, and those who are strict adherents avoid using electricity, driving cars or riding in airplanes.
Still, Kornfeld said, he acknowledged that if, one day, millions of people are living and working in space, the Jewish faith would evolve and adapt with the circumstances.
“I think one of the most beautiful things about Judaism — how it’s able to be relevant, and to adapt to all sorts of changing technologies and industry and discoveries,” he said.