Russia said it was expecting debris from its failed Mars probe to fall to earth from Sunday to Monday, but added it could not be sure of the exact crash site.
Star gazers and space agencies worldwide are scrambling to determine where and when Russia's botched $165-million mission to retrieve dust from Mars' moon Phobos will crash since it was junked in orbit after a launch in November.
Space agency Roskosmos on Thursday said atmospheric drag and solar activity might still alter the trajectory of the Phobos-Grunt craft.
It posted a map showing the likely crash area along the craft's zigzagging orbit over a broad swath of the globe, from a latitude of 51.4 degrees roughly as far north as London to 51.4 degrees as far south as the heel of Argentina.
It highlighted a centre point off Madagascar in the Indian Ocean.
"The predicted window for the fall of debris from Phobos-Grunt to Earth is between the 15th and 16th of January, with a middle point of January 15 at 1612 Moscow time (1216 GMT). The possible crash zone is within a band from 51.4 degrees north and 51.4 degrees south," said the agency in a statement.
The failure of the craft was one of a series of mishaps that marred Russian celebration of 50 years since Yuri Gagarin's pioneering first human space flight last year and hurt Moscow's pride.
In an apparent attempt to deflect blame, Russia's space agency chief has hinted at foreign sabotage of its crafts when they passed out of Russian radar range.
"It's unclear why frequent failures of our crafts occur while they are flying on what is for Russia the dark side of Earth," Vladimir Popovkin told the daily Izvestia in an interview published on Tuesday.
"I don't want to blame anyone, but there are very powerful means to interfere with spacecraft today whose use cannot be ruled out."
Popovkin did not elaborate and his spokeswoman declined a request for clarification on Wednesday.
It is unclear how much of the massive Phobos-Grunt craft will survive the fiery plunge through the atmosphere.
It carries a full payload of toxic hydrazine and nitrogen tetroxide fuel, which experts expect to burn up in orbit, and a tiny cargo of radioactive Cobalt-57.
Small chunks of a Russian communications satellite rained down on towns in Siberia striking the roof of a home situated on Cosmonaut's street after a failed launch on Dec. 23.
In August, debris from a failed cargo mission to bring supplies to astronauts aboard the International Space Station fell in a wooded area in southern Siberia.