In sync with the sun and the moon, the traditions of 1,400 years and the acts of Muslims all over the world, members of one of Egypt's seven official moon-sighting committees pulled into a parking lot high on a ridge overlooking hazy Cairo at sunset Saturday.

There were government astronomers in open-neck shirts, snapping open tripods to support their telescopes. Taking a preliminary look through the scopes at Cairo's western horizon, the astronomers didn't bother to announce what they saw at first glance: nothing.

There was a 70-year-old Muslim cleric, wearing glasses of stratified thicknesses, a gauzy black robe with gold tassels and a beatific smile. Declining a look through the telescopes, the cleric, Abdul Monim al-Berri, only sat and looked on, his presence as one of Egypt's leading religious scholars giving the gathering the stamp of religious approval. "I'm the legitimacy," he said.

And there was an al-Jazeera satellite news crew, trying to go live to tell the world the news from the parking lot, but having trouble with audio.

Frustrated, the network's reporter folded her arms across her chest and rocked back on her heels in the gravel, as she stared blindly at the sky.

Together, the committee members were on a mission: to look for the crescent moon that signals the start of Ramadan, Islam's holiest month, and to tell the world whether they had seen it.

From Senegal to Saudi Arabia and beyond, moon-spotting committees scaled minaret staircases and fanned out across deserts at twilight Saturday, as Muslims have since the founding of Islam in the 7th century, to look for a sliver of white in the sky.

Word from the committees would plunge the world's more than 1 billion Muslims into Ramadan.

For religiously observant Muslims, Ramadan is four weeks of daytime fasting and nighttime feasting with family and friends, interspersed with works of charity for the poor.

"This night of witness is extremely important for we Muslims. It is the night that unifies us all," Berri said.

In the parking lot, as around the world, ancient ways met with modern advances Saturday.

The prophet Muhammad said Muslims should begin fasting when they saw the crescent moon that opens the lunar month of Ramadan. But since the 7th century, science has provided the extras -- telescopes and observatories, for example.

The 57-nation Organization of the Islamic Conference even proposed to launch a satellite to monitor the moon for Ramadan.

Science has also allowed precise tracking of the moon and the sun, allowing astronomers to know in advance that the crescent moon starting Ramadan will be visible in the Middle East no sooner than Sunday.

In the parking lot and in most of the Middle East, technology deferred to religion. Astronomers went through the motions, at least, of looking for the crescent.

"It's a matter of Islamic law we have to be here. But it's 100 percent sure we're not going to see it today," Faleh Mohammed, head of one of Egypt's government astronomy institute, told the al-Jazeera reporter.

A rumor went through the crowd that Libya had announced the start of Ramadan -- different countries often pick different days for the start and squabble over each other's decisions.

Mohammed scoffed. "What do they see in Libya that we don't see with our telescopes?" he asked.

Mohammed Yousuf, an astronomer in his eighth year of moon-watch duty, rose from another telescope.

The last time a member of a moon-watch committee thought he had spotted a crescent moon at this point in the lunar month was in 1991, Yousuf said. Other members of the committee were able to convince the man he had seen light glancing off a bird's wings, and error was averted, Yousuf said.

Even in Muhammad's time, Yousuf recounted, a man who believed he had spotted the crescent moon was about to announce Ramadan to the world -- until a friend leaned in and removed a stray eyelash from the man's eye.

At the next telescope over, astronomer Ahmed Mohem Fathi grumbled at Cairo's pollution, thick enough to veil any moon.

By 6 p.m., Mohammed was speeding off, rushing toward a news conference in Cairo with some of Egypt's top religious and government officials to announce the findings.

The word of Egypt's grand mufti, Ali Gomaa, would be: No moon Saturday, therefore the moon's appearance Sunday was inevitable, and Ramadan would start Monday.

Egyptian radio and television carried the grand mufti's announcement live. For many of Cairo's 16 million people, the joint broadcasts were a jolting reminder that Ramadan almost was upon them.

Traffic slowed to gridlock in a half-hour. Families rushed to buy food for the first of the month's lavish meals and aid baskets.

At 6:17 p.m., the same time when the crescent is expected to appear Sunday, the astronomers bent in earnest over their telescopes.

Bystanders fell silent.

The men stood in the hush, minute after minute, squinting at the rim where earth met sky.

In the silence, the rusty voice of a single old man rose from a mosque in the valley below. Carrying out a ritual older than the moon-watch committees, the man called the faithful to evening prayers.

"Allah akbar," the mosque singer cried. "God is great."

From his chair in the parking lot, Berri raised his fingers to the sky as if to pinch the absent crescent moon.

He then brought his fingers to his mouth and kissed them.

"This is the best part, the mingling of science and religion," Berri said. "It's beautiful."

Ellen Knickmeyer