ISTANBUL, Nov. 30 — A Turkish passenger jet crashed in the mountains of western Turkey early Friday, killing all 57 people on board, including several prominent nuclear physicists on their way to a conference, Turkish authorities said. The plane, a McDonnell Douglas MD-83 operated by Atlasjet, an airline based in Istanbul, took off from Istanbul and disappeared from radar shortly before it was due to land at the airport in Isparta. It crashed about seven miles from the airport, near the town of Keciborlu, the authorities said. The cause of the crash was unclear. The weather was good, airline officials...