At 8:46 EDT this morning, exactly 10 years after the first plane hit the North Tower of the World Trade Center in New York, the nation will pause to remember the dead. President Barack Obama and former president George W. Bush will be among the officials at the ceremony, and 334 family members will read the names of the victims who were killed in the attacks. There will be six moments of silence in total: twice to mark the times each plane hit the towers, twice to mark when the towers fell, and twice to mark when the planes crashed into the Pentagon and a field in Shanksville, Pa. The 10th anniversary also marks the official opening of the National September 11 Memorial—twin reflecting pools that sit where the Twin Towers once stood. A 9/11 museum is scheduled to open at the World Trade Center site next September.