NASA had turned over the moon rock to the Honduran ambassador in September after a federal court held the chunk rightfully belonged to Honduras.

The rock was transported from the moon aboard Apollo 17. U.S. President Richard M. Nixon gave the 1.142-gram chunk to his counterpart, general Oswaldo Lopez Arellano, in 1973.

For a while the rock was displayed in the presidential residence, mounted inside a transparent globe on a wooden plaque bearing the Honduran flag. But it disappeared sometime between 1990 and 1994 and was not recovered until 1998 in the United States, where federal agents staged an elaborate sting designed to trap dealers in black-market lunar rocks.

The sting started out as an effort to catch crooks selling fakes, recalled Joseph Gutheinz, a retired senior special agent for NASA's Office of Inspector General.

"We were looking for bogus moon rocks," said Gutheinz on Saturday, speaking by phone from Houston. "It took us two months just to talk the (seller) into seeing it in a secure vault."

Confiscated from a bank vault in Miami and tested for authenticity by NASA, the moon rock stayed in the United States during a four-year court battle over its possession. No criminal charges were filed against the dealer who claimed ownership.

"To bring (the moon rock) back to a country that really appreciated that it was from the Apollo -- everyone was ecstatic that we got it back," Gutheinz said.

The rock, which measures about one-half inch (12 mm) in length will be placed on public exhibition in the Centro Interactivo Chiminike, an education center in Tegucigalpa that receives hundreds of young student visitors a day.