The metal in an Egyptian iron bead dating from around 3,300 BC has been found to have originated from space, according to analysis. Here, the bead is seen in (clockwise from top left) a photograph, a CT cross-section view, a model of nickel oxides, and a model in which blue areas represent the rich presence of nickel inside the bead. The Open University/University of Manchester hide caption

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Egyptian folk singer Dina El Wedidi performs at Qasr El Nil Theater during the Downtown Cairo Arts Festival. Wedidi says efforts to revitalize venues like the Qasr El Nil are important because there aren't enough places for musicians of the post-revolution explosion to perform. Mostafa Abdel Aty/Courtesy of Downtown Contemporary Arts Festival hide caption

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Ousted Egyptian President Hosni Mubarak, waves from behind his son, Alaa, during the opening session of Mubarak's retrial in Cairo on Saturday. AFP/Getty Images hide caption

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A bodyguard secures popular satirist Bassem Youssef, who has come to be known as Egypt's Jon Stewart, as he enters Egypt's state prosecutors office on Sunday. Amr Nabil/AP hide caption

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The wreckage of a hot air balloon and its gondola lay in a field near Luxor, Egypt, on Tuesday. A fire and subsequent crash killed many of those who were aboard the tourist flight. Reuters /Landov hide caption

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Mourners shouted during a funeral procession today in Port Said, Egypt, for some of those killed during Saturday's protests. /AFP/Getty Images hide caption

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Relatives of the Egyptian policemen who were killed in Port Said grieve during their military funeral in Cairo on Sunday. Amr Nabil/AP hide caption

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Egyptian soccer fans of Al-Ahly football club celebrate in front of their club premises in Cairo on Saturday. An Egyptian court sentenced 21 people to death in relation to a soccer stadium riot last February. Amr Nabil/AP hide caption

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Egyptians supporters of ousted former President Hosni Mubarak celebrate an appeal granted by a court in Cairo, Egypt, Sunday. Amr Nabil/AP hide caption

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Egyptians wait in line to vote on a new draft constitution in Giza, south of Cairo, on Saturday. Gianluigi Guercia/AFP/Getty Images hide caption

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Polling station officials count ballots in Cairo on Dec. 15, at the end of the first day of vote in a referendum on a new constitution. AFP/Getty Images hide caption

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Women wait in line outside a polling station to vote on a disputed constitution drafted by Islamist supporters of President Mohammed Morsi in Cairo on Saturday. Amr Nabil/AP hide caption

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An Egyptian activist holds a banner used to spray-paint graffiti on a wall urging Egyptians to vote against a draft constitution. The opposition says the constitution does not represent all Egyptians, but its efforts have not been particularly well-organized. President Mohammed Morsi and his Islamist supporters support the draft constitution. Voting begins Saturday. Gianluigi Guercia/AFP/Getty Images hide caption

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Protesters chant slogans during a demonstration in front of the presidential palace in Cairo, Egypt, on Sunday. Petr David Josek/AP hide caption

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