MOSCOW – A Russian space probe designed to boost the nation’s pride on a bold mission to a moon of Mars came down in flames Sunday, showering fragments into the south Pacific west of Chile’s coast, officials said.

Pieces from the Phobos-Ground, which had become stuck in Earth’s orbit, landed in water 775 miles west of Wellington Island in Chile’s south, the Russian military Air and Space Defense Forces said.

The military space tracking facilities were monitoring the probe’s crash, spokesman Col. Alexei Zolotukhin said. He said the deserted ocean area is where Russia guides its discarded space cargo ships serving the International Space Station.

RIA Novosti news agency, however, cited Russian ballistic experts who said the fragments fell over a broader patch of Earth’s surface, spreading from the Atlantic and including the territory of Brazil. It said the midpoint of the crash zone was in the Brazilian state of Goias.

The $170 million craft was one of the heaviest and most toxic pieces of space junk ever to crash to Earth, but space officials and experts said the risks posed by its crash were minimal because the toxic rocket fuel on board and most of the craft’s structure would burn up in the atmosphere high above the ground.

The Phobos-Ground was designed to travel to one of Mars’ twin moons, Phobos, land on it, collect soil samples and fly them back to Earth in 2014 in one of the most daunting interplanetary missions ever. It got stranded in Earth’s orbit after its Nov. 9 launch, and efforts by Russian and European Space Agency experts to bring it back to life failed.

Heiner Klinkrad, head of the European Space Agency’s Space Debris Office, which was monitoring the probe’s descent, said the craft didn’t pose any significant risks.

“This one is way, way down in the ranking,” he said from his office in Berlin, adding that booster rockets contain more solid segments that may survive fiery re-entries.

Thousands of pieces of derelict space vehicles orbit Earth, occasionally posing danger to astronauts and satellites in orbit, but as far as is known, no one has ever been hurt by falling space debris.

Russia’s space agency Roscosmos predicted that only 20 to 30 fragments of the Phobos probe, with a total weight of up to 440 pounds, would survive the re-entry and plummet to Earth.

Klinkrad agreed with that assessment, adding that about 100 metric tons of space junk fall on Earth every year. “This is 200 kilograms out of these 100 tons,” he said.