It’s about the size of an aircraft carrier and at about 10.30am on November 9 (AEDT) it will pass within the Moon’s orbit of Earth.
In astronomical terms that’s about as close as you can get without hitting – and if we were, well…..
2005 YU55 is in an orbit around our Sun and will return again in 2028. While it will be really close we won’t be able to see it with the naked eye but astronomers will use radar telescopes to observe it.
NASA will keep an eye on it through the Goldstone Deep Space Communications Complex and there is some more information on the asteroid HERE
As you can see the images of the 400 meter diameter asteroid are not good.