* Astronomy

2009 XO Earth Impact Risk Summary
Torino Scale (maximum) 0 Palermo Scale (maximum) -4.46 Palermo Scale (cumulative) -4.46 Impact Probability (cumulative) 1.1e-07 Number of Potential Impacts 1	Vimpact 16.46 km/s Vinfinity 12.11 km/s H 20.3 Diameter 0.290 km Mass 3.4e+10 kg Energy 1.1e+03 MT all above are mean values weighted by impact probability
Analysis based on 154 observations spanning 28.338 days (2009-Dec-09.152 to 2010-Jan-06.490002)

2009 XO Earth Impact Risk Summary
Torino Scale (maximum) 0 Palermo Scale (maximum) -4.38 Palermo Scale (cumulative) -4.38 Impact Probability (cumulative) 1.2e-07 Number of Potential Impacts 1	Vimpact 16.46 km/s Vinfinity 12.11 km/s H 20.3 Diameter 0.300 km Mass 3.6e+10 kg Energy 1.2e+03 MT all above are mean values weighted by impact probability
Analysis based on 137 observations spanning 26.210 days (2009-Dec-09.152 to 2010-Jan-04.362462)

Update:
The 240 - 530 metre wide asteroid 2009 XO will make a close pass (31.2 lunar distances, 0.0803 AU), travelling at 14.63 km/second, to the Earth-Moon system on the 8th January, 2010.

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The Lunar Distance (LD), the distance between Earth and the Moon, equals 384,401 km, (or 0.00256 AU).

2009 XO Earth Impact Risk Summary
Torino Scale (maximum) 0 Palermo Scale (maximum) -4.23 Palermo Scale (cumulative) -4.02 Impact Probability (cumulative) 2.9e-07 Number of Potential Impacts 2	Vimpact 16.47 km/s Vinfinity 12.13 km/s H 20.2 Diameter 0.300 km Mass 3.8e+10 kg Energy 1.2e+03 MT all above are mean values weighted by impact probability
Analysis based on 125 observations spanning 20.517 days (2009-Dec-09.152 to 2009-Dec-29.66871)