The object, which was discovered in 2006, intersects Earth's orbit twice a year and is described as "potentially hazardous" due to its proximity to our planet during its fly-bys. A fast-approaching mammoth asteroid is set to skim past Earth in less than two weeks, NASA has warned. The space rock, identified as 481394 (2006 SF6), is estimated to be some 610 metres (2,000 feet) across. That's twice the size of the Eiffel Tower, or six football fields. The 2006 SF6 is expected to come closest to Earth on Wednesday, 20 November, whisking within 0.029 astronomical units above our heads, or 4.35 million kilometres. It will fly by at a startling speed of 27,000 km/h, or around 22 times the speed of sound. This asteroid, discovered in 2006, passes by twice a year and is designated as "potentially hazardous". It belongs to the group of Aten asteroids, whose orbit occasionally cross that of our planet. Its projected trajectory shows there is hardly any chance of a collision within the next two