This weekend the bulk of the Phobos-Grunt spacecraft is forecasted to hit the atmosphere, break apart, and mostly burn up before hitting Earth.
For a Q & A from The Telegraph about Phobos-Grunt click here.
The spacecraft could hit as far north as the latitude of Calgary, Canada, and as far south as the latitude as the tip of South America.
This Russian space mission launched in November 2011 aiming for the Mars moon Phobos.
The mission was going to gather soil samples from the surface of Phobos to send back to Earth for further study.
Unfortunately, after a successful launch from Russia, rocket burns to send the Phobos-Grunt spacecraft on a course for Mars failed.
The defunct spacecraft became a useless satellite in Earth's orbit and is now falling slowly towards the top of the atmosphere.
Since the beginning of December, pieces have already fallen off and burned up over Earth.
Scientist believe the spacecraft will hit the top of the atmosphere on Sunday or Monday with friction burning up most of the pieces.
Some small pieces could reach the Earth's surface, but it's likely these will fall into one of the oceans that cover over 70% of the Earth's surface.
The greatest concern is the toxic fuel still on board because of the failed rocket burn.
This spacecraft is the heaviest piece of space junk to burn up in the atmosphere.
Besides the Phobos-Grunt spacecraft, there are thousands of pieces of space junk orbiting the Earth.
NASA tracks the trash through their Orbital Debris Program.
Pieces of space junk sometimes threaten the safety of the International Space Station (ISS).
When this happens the astronauts on board have to go into a Russian spacecraft that can be used for escape to Earth if the ISS is hit and the damage is severe enough to bring down life support systems.
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