Some more info here:
Asteroid hurtling past Earth at 9pm tonight will be closer than the moon:
http://www.independent.co.uk/news/sc...n-9170872.html
Not a threat.
As for observation, unfortunately it is going to be too faint for me in my light-polluted backyard, at 15 mag (I can just squeeze out a confirmed 13.8 to 14.0 on my 8SE in my Bortle 6 skies).
Some details here from iTelescope:
http://www.itelescope.net/sky-alerts...n-5-march.html