Pyramid-sized asteroid narrowly misses the Earth

An asteroid the size of the Great Pyramid of Giza has zipped by the Earth closer than the moon.

2019 OD, about 120m across and travelling at 20km per second, narrowly missed us at 1:30am on Thursday (NZ time). It flew by only 357,540km away - the moon is 384,400km distant.

It was only spotted for the first time by NASA three weeks ago.

The path 2019 OD took near Earth.
The path 2019 OD took near Earth. Photo credit: NASA

Two smaller asteriods also flew by - 50m-wide 2019 OE a couple of hours earlier and 110m-wide 2015 MH10 half an hour afterwards.

If 2019 OD hit the Earth, it has the potential to cause an explosion with energy almost equivalent to the largest nuclear bomb ever detonated, the Soviet Union's Tsar Bomba.

But neither 2019 OD or the other two asteroids were considered a threat by NASA, which was able to track their paths. There have been a number of close calls in the past year, but the space agency hasn't raised fear about any of them. 

An asteroid that exploded in skies over the Caribbean in June was spotted by astronomers 12 hours earlier, potentially giving residents below the chance to evacuate had it been on track to hit a populated area.