A 1,000 m wide mammoth asteroid, which is travelling at more than 23,000 mph in space, is predicted to skim past Earth on Friday.
If the asteroid called 2014-YB35 hit Earth it could wipe out a country, and poses a very real threat to the planet, the Mirror reported.
It's not unusual for small meteorites to pass close by; however one of this size was a very rare occurrence. Any impact would trigger devastating changes in the climate, earthquakes and tsunamis.
This rock has been forecasted to pass within 2.8 million miles, a tiny distance in astronomical terms of Earth on Friday, according to NASA's Near Earth Object Programme.
The object was first spotted by the Catalina Sky Survey at the end of 2014 with astronomers expected to be closely watching its progress this week.
If it hit Earth, plumes of debris would be thrown into the atmosphere, changing the climate and potentially making the planet inhabitable for all life. Smaller impacts would be capable of destroying cities.