NASA has admitted that when it comes to asteroids that threaten life on Earth, they are flying blind. An asteroid the size of an Olympic swimming pool, large enough to wreak havoc on a regional scale, flew “an astromical hair’s breadth” away from Earth on Sunday – and NASA didn’t even know it was coming. This asteroid was big, but not as large as the hurtling space rock believed to be responsible for the demise of the dinosaurs. That asteroid is estimated to have been about 6.2 miles (10km) across. And the rock which hit Tunguska in Siberia in 1908 – a major event in asteroid history – scorching forest and flattening trees across thousands of square miles, is believed to have been between 200 and 620 feet wide (60 and 190 metres). Are these asteroids actually a danger to life on Earth? According to Space.com, an asteroid would need to have a girth of more than 0.6 miles (1 km) to have the force to destroy humanity. However a smaller space rock could devastate a whole continent, or wipe the population of a major country like the U.S. off the map. But would NASA even see it coming? Experts [...]
