coming this way...called 1999 RQ36 at the odds of 1 in 1000 of hitting the earth...well..not bad odds. Good luck future people..and don't go too crazy when the time gets near.
Or China's... or India's... or Japan's. The odds will change the closer it gets... for better or worse.
1 kilometer.... to put that in perspective if a 10-15m wide asteroid can impact with 4 to 5 times the force of the hiroshima bomb the devastation caused by a 1km asteroid doesnt even bear thinking about. and 1/300 odds? like someone said, glad i wont be alive to see that.
With a size that small it would be possible to break it up into small pieces even with today's technology, let alone 171 years in the future. A couple probes with hydrogen bombs might just leave enough behind for the fragment shower to be pretty.