Asteroid 2013 NJ is just one object on NASA's list of near-Earth objects, but it's remarkable in that it flew by significantly closer than anything else on the list. Passing by at about 2.5 times the distance to the moon, it was close enough to be visible to the naked eye, even though its diameter is relatively small at 120-260 meters.

Luckily for us, when something passes extremely close in terms of space, say 2.5 lunar distances, it's actually still a pretty large distance away in actuality. Unluckily, the size of objects is also subjected to that relative sense of scale, as something that's relatively small in space terms, say 120-260 meters, is actually pretty large if it comes hurtling towards you.

While it's not all that big among asteroids, even something of that size could have cause a lot of damage if it hadn't sailed harmlessly past. The meteor that hit Russia earlier this year was only 17-20 meters wide, but it also weighed 13-14,000 tons and injured 1,500 people. An asteroid like 2013 NJ, which is at least six times that size, would cause a lot more damage. So we're lucky that it kept its distance this time around.

Also unlike the Russian meteor, NASA knew about 2013 NJ and fairly accurately predicted the distance at which it would pass us, so that's at least comforting - as comforting as anything gets when giant space rocks are flying around your home at several kilometers per second.

Sources: Universe Today and NASA