If you thought you would get a forewarning about a potential asteroid impacting the Earth – think again!

A large asteroid impacted the Earth in March with no warning – and most people still haven’t heard about it.

Many “near-Earth objects” (NEOs) do not cross any telescope’s line of sight, and several potentially dangerous asteroids have snuck up on Earth in recent years. “Luck is not a plan,” Richard Binzel, an asteroid researcher and professor of planetary sciences at MIT, told Business Insider in September. In case scientists discover such an asteroid approaching Earth again, NASA has considered some ways to push it off its collision course: slamming a spacecraft into it, detonating an explosion near it, or firing lasers that heat and vaporize the rock enough to change its orbit. But that takes time and the technology is unproven. What if nobody spots the asteroid until it’s too late?

In recent years, scientists have missed plenty of large, dangerous objects approaching Earth. “We feel we’ve only found about a third of the population of asteroids that are out there that could represent an impact hazard to the Earth,” Johnson said. In 2013, a meteor measuring about 65 feet in diameter and traveling at 40,000 mph entered the atmosphere and exploded over Chelyabinsk in central Russia. The blast sent out a shock wave that broke windows and damaged buildings across the region, injuring more than 1,400 people.  –Business Insider