Prosecutors say a scientist who worked on the cutting edge of moon exploration has been caught trying to sell classified secrets to an FBI agent posing as an Israeli intelligence agent. Stewart David Nozette, who is credited with helping discover evidence of water on the moon and has been a leader in recent lunar exploration work, was arrested Monday and charged in a criminal complaint with attempting to communicate, deliver and transmit classified information, the Justice Department said. Nozette, 52, of Chevy Chase, Maryland, was expected to make his initial appearance in federal court in Washington on Tuesday. Law enforcement officials said Nozette did not immediately have a lawyer. Nozette worked in various jobs for the Energy Department and NASA. In 1989 and 1990, he worked for the White House's National Space Council. He developed the Clementine bi-static radar experiment that is credited with discovering water on the south pole of the moon. He also worked at the Energy Department's Lawrence Livermore National Laboratory, where he designed highly advanced technology, from approximately 1990 to 1999. At Energy, Nozette held a special security clearance equivalent to the Defense Department's top secret and "critical nuclear weapon design information" clearances. DOE clearances apply to access to information specifically relating to atomic or nuclear-related materials. Nozette also held top offices at the Alliance for Competitive Technology, a nonprofit corporation that he organized. Between January 2000 and February 2006, Nozette, through his company, had several agreements to develop advanced technology for the US government. To build a case against Nozette, FBI agents posed as officers of the Israeli intelligence service Mossad, and the criminal complaint suggests why they thought their suspect would take the bait. From 1998 to 2008, the complaint alleges, Nozette was a technical adviser for a consultant company that was wholly owned by the Israeli government. Nozette was paid about $225,000 over that period, the court papers say. Then, in January of this year, Nozette allegedly traveled to another foreign country with two computer thumb drives and apparently did not return with them. Prosecutors also quote an unnamed colleague of Nozette who said the scientist said that if the US government ever tried to put him in jail for an unrelated criminal offense, he would go to Israel or another foreign country and "tell them everything" he knows. The complaint does not allege that the government of Israel or anyone acting on its behalf violated US law. In Jerusalem, Israeli government officials had no immediate comment. The affidavit by FBI agent Leslie Martell said that on Sept. 3, Nozette received a telephone call from an individual purporting to be an Israeli intelligence officer, but who was actually an undercover FBI agent. Nozette agreed to meet with the agent later that day at a hotel in Washington and in the subsequent meeting the two discussed Nozette's willingness to work for Israeli intelligence, the affidavit said. Nozette allegedly informed the agent that he had, in the past, held top security clearances and had access to US satellite information, the affidavit said. The scientist also allegedly said that he would be willing to answer questions about this information in exchange for money. The agent explained that the Israeli intelligence agency, Mossad, would arrange for a communication system so Nozette could pass on information in a post office box. Nozette agreed to provide regular, continuing information and asked for an Israeli passport, the affidavit alleged. According to the court papers, Nozette and the undercover agent met soon afterward in the same hotel, where the scientist allegedly said that while he no longer had legal access to any classified information at a US government facility, he could, nonetheless, recall classified information from memory. Nozette allegedly told the agent, "Well, I should tell you my first need is that they should figure out how to pay me ... they don't expect me to do this for free." About a week later, FBI agents left a letter in the designated post office box, asking Nozette to answer a list of questions about US satellite information. The agents provided a $2,000 cash payment. Nozette was later captured on videotape leaving a manila envelope in the post office box. The next day, agents retrieved the sealed envelope and found, among other things, a one-page document containing answers to the questions and an encrypted computer thumb drive. One answer contained information classified as secret, which concerned capabilities of a prototype overhead collection system. Nozette allegedly offered to reveal additional classified information that directly concerned nuclear weaponry, military spacecraft or satellites, and other major weapons systems. Agents then asked for more information, and again he allegedly provided it, in exchange for a cash payment of $9,000. Over the course of his career, Nozette performed some of his research at the US Naval Research Laboratory in Washington, the Defense Advanced Research Projects Agency in Arlington, Virginia, and the National Aeronautics and Space Administration Goddard Space Flight Center in Greenbelt, Maryland.