Contents  on 16 December '12

Asteroid/Comet Connection (A/CC) Resources:

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Traffic Report  on 16 December '12

Seven objects reported inside ten LD

There are seven objects reported to be inside ten lunar distances (LD) of our planet today. Within Earth's Hill sphere, risk-listed intruder 2012 XL134 is outbound from 1.06 to 3.09 LD, 2012 XP134 from 1.45 to 3.01 LD, and radar target intruder 2012 XB112 from 1.55 to 2.41 LD, while risk-listed 2012 XH112 exits the sphere, moving from 1.99 to 4.56 LD. And risk-listed 2012 XM16 comes its closest to Earth on this passage, reaching 3.11 LD at 2037 UT.

More distantly, radar target 2012 XM55 is inbound from 5.83 to 5.30 LD and 2012 XN134 is outbound from 6.14 to 7.30 LD.

Coming toward Earth next, 2012 XP55 arrives inside ten LD on December 26th

This report was generated at 1647 UTC with the recovery of, and first follow-up for departed 2012 XL16 and the first follow-up for departed 2012 XO134 in today's DOU MPEC, along with observations of 2012 XM55 and departed objects 2012 XK134, 2012 XJ134, 2012 XJ112, and 2012 XP55.

Notes: Ten times the distance to the Moon (ten LD) has no astronomical significance but is a useful reporting boundary. Earth's Hill sphere (of gravitational influence) is estimated to extend out to around 3.89 LD. Object distances are interpreted by A/CC from JPL Horizons data. See also current sky chart and object details (alt-details), ephemerides, and today's timeline.

NEOCP Activity  on 16 December '12

The MPC's NEO Confirmation Page has 6 listings

When last checked at 2359 UTC today, the Minor Planet Center's Near Earth Object discovery Confirmation Page (NEOCP) had six objects listed. Of these, three were "one nighters." So far The Tracking News has counted a total of eight listings on the NEOCP today.

To learn how observers use the NEOCP, see the Practical guide on how to observe NEOCP object at Suno Observatory by Birtwhistle et al.

New MPECs  on 16 December '12

Minor Planet Electronic Circulars

As of last check at 2359 UTC, there have been three MPECs posted today from the International Astronomical Union's Minor Planet Center in Cambridge, Massachusetts.

MPEC 2012-Y03 - "17:46 UT" - 2005 RK3

<< DOU on 16 Dec. '12 >>  MPEC 2012-Y02 - "06:05 UT" - Daily Orbit Update

MPEC 2012-Y01 - "03:45 UT" - Comet C/2012 X2 (Panstarrs)

Observers  on 16 December '12

Nineteen observers appear in today's MPECs.

CodeObserver / observatory
H21Astronomical Research Obs. Westfield in Illinois, 12 in MPECs 2012-Y01 & 2012-Y02 -- 2012 XT93, 2012 XR93, 2012 XM55, 2012 XM134, 2012 XG16, 2012 XF17, 2012 XF112, 2012 XD55, 2012 XD112, C/2012 X2, 2012 WQ10, 2012 US136
C77Bernezzo Obs. in Italy, 1 in MPEC 2012-Y02 -- 4179
B88Bigmuskie Obs. in Italy, 2 in MPEC 2012-Y02 -- 214869, 12538
807|Robert Holmes in Illinois via Cerro Tololo Inter-American Obs. (CTIO) in Chile, 16 in MPECs 2012-Y01 & 2012-Y02 -- 2012 XZ6, 2012 XZ132, 2012 XQ93, 2012 XQ55, 2012 XO134, 2012 XK112, 2012 XJ134, 2012 XH55, 2012 XE112, 2012 XD112, 2012 XC133, C/2012 X2, 2005 XV77, 2004 BE85, 2002 GJ8, 88213
958Dax Obs. in France, 1 in MPEC 2012-Y02 -- 137805
J04ESA Optical Ground Station (ESA OGS) in the Canary Islands, 10 in MPECs 2012-Y01 & 2012-Y02 -- 2012 XR111, 2012 XP111, 2012 XO134, 2012 XM55, 2012 XL16, 2012 XJ112, 2012 XG, 2012 XC133, 2012 XA133, C/2012 X2
E89Geyserland Obs. in New Zealand, 1 in MPEC 2012-Y02 -- 138937
J95Great Shefford Obs. in England, 3 in MPEC 2012-Y02 -- 2012 XT134, 2012 XM134, 2012 XK134
H15ISON-NM Obs. in New Mexico, 1 in MPEC 2012-Y02 -- 2012 TM139
W85LCOGT Cerro Tololo A in Chile, 1 in MPEC 2012-Y01 -- C/2012 X2
704LINEAR in New Mexico, 11 in MPECs 2012-Y01 & 2012-Y02 -- 2012 XS111, 2012 XJ134, 2012 XD55, 2012 XD133, 2012 XC55, C/2012 X2, 2008 YZ28, 2008 WJ60, 333358, 137925, 3838
H01Magdalena Ridge Obs. in New Mexico, 1 in MPEC 2012-Y01 -- C/2012 X2
5682David Tholen's team on Mauna Kea in Hawaii, 3 in MPECs 2012-Y01, 2012-Y02 & 2012-Y03 -- C/2012 X2, 2005 RK3, 1999 NW2
B67Mirasteilas Obs. in Switzerland, 1 in MPEC 2012-Y02 -- 4179
J47Nazaret Obs. in Spain, 1 in MPEC 2012-Y02 -- 4179
F51Pan-STARRS 1 (PS1) in Hawaii, 2 in MPECs 2012-Y01 & 2012-Y02 -- C/2012 X2, 137199
H06|Hidetaka Sato in Japan via RAS Obs. Mayhill in New Mexico, 1 in MPEC 2012-Y01 -- C/2012 X2
C48Sayn Solar Obs. in Russia, 2 in MPEC 2012-Y02 -- 2012 XP55, 2012 XD133
E12Siding Spring Survey in New South Wales, 1 in MPEC 2012-Y02 -- 2012 TX78
For a list of all participating observatories that have Web addresses, see A/CC's Observatory Links page.

Impact Risk Monitoring  on 16 December '12

Summary Risk Table for Risk Assessments Updated Today   (last checks: NEODyS and JPL at 2359 UTC)
See the CRT page for a list of all objects rated recently as risks and our ephemerides page for a list of risk-listed objects under current observation.
The time horizon for JPL is 100 years from today and for NEODyS is usually the year 2090. Both also post impact solutions beyond 100 years for a few special objects.
For the latest official risk assessments, and for explanations of the terminology, see the JPL NEO Program Sentry and NEODyS CLOMON2 risk pages.





Notes for Today's Latest Risk Assessments
2012 XT134JPL Sentry1645203411.2e-10-5.82-5.820JPL: "Analysis based on 34 observations spanning 4.6988 days (2012-Dec-11.41331 to 2012-Dec-16.11209)." Diameter approximately 0.670 km. from mean, weighted H=18.5.
NEODyS1645R E M O V E D-
2012 XM134JPL Sentry16452050-208341.1e-07-5.71-6.010JPL: "Analysis based on 21 observations spanning 2.8751 days (2012-Dec-13.17577 to 2012-Dec-16.05088)." Diameter approximately 0.110 km. from mean, weighted H=22.5.
NEODyS16452050-206223.95e-09-7.26-7.260NEODyS: "Based on 21 optical observations (of which 0 are rejected as outliers) from 2012-12-13.177 to 2012-12-16.052."
2012 XK134JPL Sentry16452106-210826.7e-10-10.30-10.40JPL: "Analysis based on 28 observations spanning 2.9246 days (2012-Dec-13.14593 to 2012-Dec-16.07055)." Diameter approximately 0.018 km. from mean, weighted H=26.4.
NEODyS16452065-206511.01e-07-7.87-7.870NEODyS: "Based on 28 optical observations (of which 0 are rejected as outliers) from 2012-12-13.147 to 2012-12-16.071."

Legend: VI# = VI count, Prob Cum = cumulative probability, PS Cum/Max = cumulative/maximum Palermo Scale, TS = Torino Scale

An impact solution, also known as a "virtual impactor" (VI), is not a prediction but rather a possibility derived from a variant orbit calculation that cannot be eliminated yet based on the existing data. Elimination can come quickly with just a little further observation or may take weeks or months, sometimes years. Once superceded or eliminated, a former impact solution has zero relevance to an object's risk. See Jon Giorgini's "Understanding Risk Pages" to learn more.

Chronology  on 16 December '12

Times are UTC for when items were noted or added by The Tracking News.

1800Grabbed MPEC 2012-Y03 - 2005 RK3 - see above
1647Generated Traffic Report
1645Noted that JPL Sentry has updated its 2012 XK134 risk assessment - see above
Noted that NEODyS has updated its 2012 XK134 risk assessment - see above
Noted that JPL Sentry has updated its 2012 XM134 risk assessment - see above
Noted that NEODyS has posted 2012 XM134 as an impact risk - see above
Noted that JPL Sentry has updated its 2012 XT134 risk assessment - see above
Noted that NEODyS has removed 2012 XT134 as an impact risk - see above
Grabbed MPEC 2012-Y02 - Daily Orbit Update - see above
0702Grabbed MPEC 2012-Y01 - Comet C/2012 X2 (Panstarrs) - see above