Back in 1974 he published a booklet in Arabic, titled The Mobility of the Sun and Moon and the Immobility of the Earth, in which, relying on a verse from the Koran, he stated: "The earth is flat. Whoever claims it is round is an atheist deserving of punishment."
In 1993 the same Shiek, as the highest religious authority of Saudi Arabia (and presumably the world), issued a fatwa explicitly declaring that anyone suggesting that the earth was not flat was a blasphemer and must be punished.
Apart from this Sheik, the Islamic Calendar is pretty fair evidence of the meagre astronomical understanding of the Moslems. It is a lunar calendar - but unlike the Jewish or Chinese calendars it makes no effort to reconcile itself to the solar year - so the year is about 356 days long, each date occurring approximately nine days earlier than in the year before so that, for example, the month of Ramidan churns around the seasons making a complete cycle in about 19 years. Worse than that, although both the Jews and Chinese were able many centuries ago to calculate the lunar cycles with precision, the Islamic date will not be set in advance by mathematical calculation, instead the beginning of the month commences with the actual eyewitness viewing of the first crescent of the moon, without regard to astronomic predictions, and there continue to be lively arguments almost every year among Moslems about whether the first day of the month begins when that crescent is visible in Baghdad or Mecca or Cairo (considering the motion of the moon, it occasionally happens that the moon is not yet lit in its first crescent until after it passes over part of the Arab world, or one of those cities might have bad weather), with the result that, every now and then, those calendars that were printed in advance are put in the wrong.
Aha! So Columbus was WRONG after all these years.