Contents  on 18 December '12

Asteroid/Comet Connection (A/CC) Resources:

The latest A/CC news is available via framed access, RSS news feed RSS news feed, or redirection. - Note: A/CC has a main Web site and also a backup site with its own duplicate RSS news feed.

Navigation tips: Use the << and >> arrows on the menus for each regular section (Observers, Risks, etc.) to move to the previous and next day's news for that section. Use the Index menu item to access specific days through a calendar interface. And use the all-up news archive to access news from any time since A/CC began in early 2002. To keep track of what's new each day, watch the Chronology section.

Traffic Report  on 18 December '12

Seven objects reported inside ten LD

Seven objects are reported to be inside ten lunar distances (LD) of our planet today. Radar target intruder 2012 XB112 exits Earth's Hill sphere, moving from 3.32 to 4.24 LD, and radar target 2012 XM55 is inbound from 4.79 to 4.32 LD. Risk-listed 2012 XM16 is outbound from 4.56 to 6.98 LD, 2012 XP134 from 4.88 to 6.81 LD, intruder 2012 XL134 from 5.29 to 7.50 LD, 2012 XN134 from 8.61 to 10.00 LD, and 2012 XH112 departs from inside ten LD, traveling from 7.66 to 10.83 LD.

Headed our way next, 2012 XP55 arrives inside ten LD on December 26th.

This report was generated at 1439 UTC with follow-up in today's DOU MPEC for 2012 XL134, 2012 XH112, 2012 XP55, 2012 XM55, and departed 2012 XO134.

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 18 December '12

The MPC's NEO Confirmation Page has 3 listings

When last checked at 2300 UTC today, the Minor Planet Center's Near Earth Object discovery Confirmation Page (NEOCP) had three objects listed. Of these, two 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 18 December '12

Minor Planet Electronic Circulars

As of last check at 2300 UTC, there have been two MPECs posted today from the International Astronomical Union's Minor Planet Center in Cambridge, Massachusetts.

MPEC 2012-Y08 - "21:48 UT" - 2012 YK

<< DOU on 18 Dec. '12 >>  MPEC 2012-Y07 - "06:04 UT" - Daily Orbit Update

Observers  on 18 December '12

A total of 22 observers appear in today's MPECs.

CodeObserver / observatory
H21Astronomical Research Obs. Westfield in Illinois, 11 in MPEC 2012-Y07 -- 2012 XP55, 2012 XK16, 2012 XJ55, 2012 XF17, 2012 XE17, 2012 XC55, 2012 XC112, 2012 VM82, 2012 VL94, 2012 UX27, 2012 TA219
807|Robert Holmes in Illinois via Cerro Tololo Inter-American Obs. (CTIO) in Chile, 8 in MPEC 2012-Y07 -- 2012 XR134, 2012 XO134, 2012 WK4, 2012 VP76, 2012 TQ256, 2012 QB17, 2012 PQ28, 65690
J19El Maestrat Obs. in Spain, 1 in MPEC 2012-Y07 -- 4179
E103program code 3 via Faulkes Telescope South in New South Wales, 1 in MPEC 2012-Y08 -- 2012 YK
J95Great Shefford Obs. in England, 1 in MPEC 2012-Y07 -- 2012 XL134
D00ISON-Kislovodsk Obs., 1 in MPEC 2012-Y07 -- 2008 XE2
695]Mark Trueblood via Kitt Peak Natl. Obs. (KPNO) in Arizona, 5 in MPEC 2012-Y07 -- 2012 XS93, 2012 XM55, 2012 XD112, 2012 WK4, 2002 AY1
704LINEAR in New Mexico, 9 in MPECs 2012-Y07 & 2012-Y08 -- 2012 YK, 2012 XQ93, 2012 XC55, 2012 XC112, 2010 XT45, 2008 YZ28, 36284, 214869, 3908
J38La Vara Obs. in Spain, 1 in MPEC 2012-Y07 -- 4179
130Lumezzane Obs. in Italy, 7 in MPEC 2012-Y07 -- 2012 XE17, 2012 VJ82, 2012 VF37, 2012 SA59, 345705, 163364, 3838
C41MASTER-II Obs. Kislovodsk in Russia, 1 in MPEC 2012-Y07 -- 137199
5682David Tholen's team on Mauna Kea in Hawaii, 1 in MPEC 2012-Y07 -- 2012 OP4
0892Oleksandr V. Shulga via Nikolaev Obs. in the Ukraine, 3 in MPEC 2012-Y07 -- 2012 XH112, 2012 VF37, 4179
F51Pan-STARRS 1 (PS1) in Hawaii, 2 in MPEC 2012-Y07 -- 2010 XL56, 229672
H06|Hidetaka Sato in Japan via RAS Obs. Mayhill in New Mexico, 1 in MPEC 2012-Y07 -- 2012 XM134
104San Marcello Pistoiese Obs. in Italy, 1 in MPEC 2012-Y08 -- 2012 YK
H36Sandlot Obs. in Kansas, 1 in MPEC 2012-Y08 -- 2012 YK
691Spacewatch 0.9m telescope in Arizona, 2 in MPEC 2012-Y07 -- 2012 UZ33, 2012 UD34
291Spacewatch 1.8m telescope in Arizona, 7 in MPEC 2012-Y07 -- 2012 VF5, 2012 VA5, 2012 UR136, 2012 TV78, 2012 TP139, 2005 YQ96, 2002 XQ40
C36Starry Wanderer Obs. in Belarus, 1 in MPEC 2012-Y07 -- 2001 YM2
926Tenagra II Obs. in Arizona, 3 in MPEC 2012-Y07 -- 2012 XD55, 222165, 141052
C44Volta Obs. in Italy, 1 in MPEC 2012-Y08 -- 2012 YK
For a list of all participating observatories that have Web addresses, see A/CC's Observatory Links page.

Impact Risk Monitoring  on 18 December '12

Summary Risk Table for Risk Assessments Updated Today   (last checks: NEODyS and JPL at 2325 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 XM134JPL Sentry14372060-208336.1e-09-7.06-7.170JPL: "Analysis based on 26 observations spanning 4.2769 days (2012-Dec-13.17577 to 2012-Dec-17.45262)." Diameter approximately 0.100 km. from mean, weighted H=22.6.
NEODyS1437R E M O V E D-
2012 XL134JPL Sentry1437R E M O V E DJPL: Risk listing removed at 0952 UTC.
1998 WD31NEODyS1437R E M O V E D-

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 18 December '12

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

2300Grabbed MPEC 2012-Y08 - 2012 YK - see above
1439Generated Traffic Report
1437Noted that NEODyS has removed 1998 WD31 as an impact risk - see above
Noted that JPL Sentry has removed 2012 XL134 as an impact risk - see above
Noted that JPL Sentry has updated its 2012 XM134 risk assessment - see above
Noted that NEODyS has removed 2012 XM134 as an impact risk - see above
Grabbed MPEC 2012-Y07 - Daily Orbit Update - see above