chongo's Journal: 2003-CR20 asteroid update for 2003-Mar-01 22:00 UTC

Good news!!! With 115 observations over almost 18 days, 2003-CR20 risk has been lowered to the point where is no longer has a Torino impact hazard scale of 1!

Based on the new observations, we calculate the following information for 2003-CR20:

• Diameter: 604m (up from 560m)
• Mass: 3.0e11 kg (up from 2.4e11 kg)
• Potential impact speed 25.10 km/sec (up from 24.85 km/sec)
• Potential impact energy(only IF it hits): 23,000 Megatons (up from 18,000 Megatons)
• Torino impact hazard scale : 0 (down from 1)
• cumulative Palermo Scale : -3.09 (down from -1.04)
• close Earth approach paths in next 100 yrs: 5 (down from 13)
• Earth impact odds in the next 100 yrs: 1 in 4,167,000 (down from 1 in 20,000)

There is a 99.999976% chance the asteroid will miss the Earth during the next 100 years.

The following is a table of the close Earth approaches by 2003-CR20 where Earth lies within the 5-sigma path. See my explination for the data in this table. The 5-sigma approaches as of the time of this Journal entry are:

1. 2031-09-20.56 1.04 +/-0.353 (Earth inside 3-sigma path)
2. 2043-09-20.19 0.29 +/-0.593 (Earth inside 1-sigma path)

The most significant close approaches have been marked in bold. The ''highest risk'' approach is 2043-09-20.19 0.29 +/-0.593 with only a 1 in 111,111,000 chance that 2003-CR20 will impact the Earth on that pass.

The 2003-CR20 orbit model has become much better for the Earth. It has dropped to 4th place on the current impact risks table. As of 2003-Feb-28 21:00 UTC the refined model's Torino impact hazard scale had dropped to the -2's, but we didn't have time to port a Journal update. As more data comes in, 2003-CR29 risk seems to be declining further.

It has been shown that 2003-CR20 had an encounter with Venus on 1960-01-23.33 with a pass somewhere under the 1,000,000 km range. This encounter may have been the event to have nudged 2003-CR20 into its current high-risk orbit. This high-risk orbit will not last long as an close encounter with Mars in 2096-01-07.15 and another with Venus in 2097-11-12.28 will move 2003-CR20's orbit further away from Earth's path.

2003-CR20 seems to be a wild slingshot ride among Venus, Earth and Mars. Only time will tell where it ends up, but for the next 100 years it is VERY unlikely that it will hit the Earth. No doubt 2003-CR20 will be watched on future trips near Earth. New data may shed new light in the long term nature of its orbit. But the next few years we seem to be safe from that asteroid.

We hope you have enjoyed watching these updates as much as we enjoyed the challenge of modeling this very unusual orbit.

P.S. There is no change is status for 1997-XR2. That asteroid remains as the only non-zero Torino impact hazard scale object.