As reported, asteroid 2012 LZ1 came about 5.3 million km (3.3 million miles) from planet Earth on its closest approach on June 14th, 2012. The fairly big and unusually bright space rock is about 502 meters (1,650 feet) wide. The Remanzacco Observatory crew of Nick Howes, Ernesto Guido & Giovanni Sostero captured this imagery of the pass.
Ian Musgrave in Australia also took some imagery of the pass:
According to a little research by David Dickinson (@Astroguyz on Twitter) by looking at ESA’s NEODYS-2 website, this rock won’t be back in Earth’s vicinity again until June 12th, 2053, and will be about 3 times as distant.
There was no danger this asteroid would impact Earth at the distance it passed, and it appears it won’t be a problem in the future. But it has been classified as a Potentially Hazardous Asteroid. PHAs are asteroids larger than approximately 100 meters that can come closer to our planet than 0.05 AU (7.4 million km, 4.65 million miles). None of the known PHAs is on a collision course with our planet, although, as the Remanzacco team pointed out, astronomers are finding new ones all the time.
See the Minor Planet Center for more details on this object.