Asteroid 2012 LZ1 - discovered on June 12 - was recently classified as potentially hazardous by the Minor Planet Center because its preliminary orbit brings it close to Earth (within 20 lunar distances).
Astronomers have now determined that LZ1 is twice as large as originally estimated based on its brightness, and large enough to have serious global consequences if it were to hit the Earth.
"This object turned out to be quite a bit bigger than we expected, which shows how important radar observations can be, because we're still learning a lot about the population of asteroids," explained Dr. Ellen Howell of the Arecibo Observatory.
According to Howell, astronomers closely observed the asteroid on June 19, 2012, to measure its orbit more precisely and determine its size, rotation rate, and shape.
LZ1 was subsequently found to measure approximately 1 kilometer (0.6 miles) in its largest dimension - suggesting that 2012 LZ1 must be quite dark, as it reflects only 2-4% of the light that hits it.
However, scientists have also concluded that the asteroid object does not have any chance of hitting the Earth for at least the next 750 years.
"The sensitivity of our radar has permitted us to measure this asteroid's properties and determine that it will not impact the Earth at least in the next 750 years," confirmed Dr. Mike Nolan, Director of Planetary Radar Sciences at Arecibo Observatory.
Asteroid 2012 LZ1 is roughly spherical in shape and rotates once around every 10-15 hours.