Russia’s Defence Ministry said a failed probe designed to travel to a moon of Mars has crashed, showering debris over the southern Pacific, according to news reports.

The Ministry said the fragments fell on Sunday 1,250 kilometres west of Wellington Island.

The Phobos-Grunt was one of the heaviest and most toxic space junk ever to crash to Earth, but space officials and experts said the risks posed by its crash were minimal as the probe’s toxic rocket fuel and most of the craft’s structure were to burn up in the atmosphere anyway.

The $170-million Phobos-Grunt was Russia’s most expensive and the most ambitious space mission since Soviet times. The spacecraft was intended to land on Phobos, one of Mars’ two moons, collect soil samples and fly them back to Earth.