A millennium ago, when Europe was in its dark ages, Persia and the rest of the Muslim world were dotted with observatories. Copernicus even drew on the meticulous records of planetary motion from the observatory at Maragheh in northwestern Iran for his proposal that Earth revolves around the sun. That astronomical tradition is due to resume next spring, as construction begins on the $30 million Iranian National Observatory, a 3.4-meter optical telescope. When completed in 4 or 5 years, it could be the best general-purpose telescope for thousands of kilometers. A monument to the persistence of Iran’s tiny astronomy community in the face of shifting political winds, the telescope will study exoplanets and gamma-ray bursts, hunt for dark matter, and probe galaxy formation.To read the full story, see the 4 September issue of Science.