Contents  on 22 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 22 December '12

Three objects reported inside ten LD

There are three objects reported within ten lunar distances (LD) of our planet today. Inside Earth's Hill sphere, radar target 2012 XM55 is inbound from 3.26 to 3.10 LD. Further away, radar target intruder 2012 XB112 is outbound from 7.04 to 7.99 LD and risk-listed 2012 YR1 from 7.65 to 9.02 LD.

Coming to the neighborhood next, 2012 YS1 arrives inside ten LD tomorrow and 2012 XP55 arrives on December 26th.

This report was generated at 1659 UTC with follow-up in today's DOU MPEC for 2012 XP55 and departed objects 2012 XK134, 2012 XT111, and 2012 XL16.

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 22 December '12

The MPC's NEO Confirmation Page has 33 listings

When last checked at 2352 UTC today, the Minor Planet Center's Near Earth Object discovery Confirmation Page (NEOCP) had 33 objects listed. Of these, seventeen were "one nighters." So far The Tracking News has counted a total of 34 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 22 December '12

Minor Planet Electronic Circulars

As of last check at 2352 UTC, there has been one MPEC posted today from the International Astronomical Union's Minor Planet Center in Cambridge, Massachusetts.

<< DOU on 22 Dec. '12 >>  MPEC 2012-Y19 - "06:04 UT" - Daily Orbit Update

Observers  on 22 December '12

Thirteen observers appear in today's MPEC.

CodeObserver / observatory
703Catalina Sky Survey (CSS) in Arizona, 5 in MPEC 2012-Y19 -- 2012 XP55, 2012 TA79, 159533, 152742, 137052
J04ESA Optical Ground Station (ESA OGS) in the Canary Islands, 8 in MPEC 2012-Y19 -- 2012 XT111, 2012 XR111, 2012 XP111, 2012 XM134, 2012 XL16, 2012 XF133, 2012 XE133, 2012 XC133
J19El Maestrat Obs. in Spain, 2 in MPEC 2012-Y19 -- 192563, 5646
H15ISON-NM Obs. in New Mexico, 1 in MPEC 2012-Y19 -- 2010 QD2
168Kourovskaya Obs. in Russia, 7 in MPEC 2012-Y19 -- 2012 QF49, 2001 YM2, 1994 XD, 345705, 277127, 192563, 4179
704LINEAR in New Mexico, 4 in MPEC 2012-Y19 -- 2012 FS62, 2004 YC5, 68548, 177651
H01Magdalena Ridge Obs. (MRO) in New Mexico, 2 in MPEC 2012-Y19 -- 2012 XK134, 2012 XE133
G96Mt. Lemmon Survey (MLS) in Arizona, 6 in MPEC 2012-Y19 -- 2006 OF15, 2001 YM2, 85490, 190161, 153220, 137199
F51Pan-STARRS 1 in Hawaii, 1 in MPEC 2012-Y19 -- 11405
H23Pear Tree Obs. in Florida, 1 in MPEC 2012-Y19 -- 4179
291Spacewatch 1.8m telescope in Arizona, 10 in MPEC 2012-Y19 -- 2012 XS93, 2012 XS111, 2012 XR134, 2012 XR111, 2012 XQ111, 2012 XP111, 2012 XG, 2012 XD112, 2012 WC25, 2012 WB25
H47Vicksburg Obs. in Mississippi, 2 in MPEC 2012-Y19 -- 2012 XC112, 4179
G33Wickede Obs., 1 in MPEC 2012-Y19 -- 4179
For a list of all participating observatories that have Web addresses, see A/CC's Observatory Links page.

Impact Risk Monitoring  on 22 December '12

Summary Risk Table for Risk Assessments Updated Today   (last checks: NEODyS and JPL at 2352 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 XK134NEODyS16562096-209611.5e-08-8.92-8.920NEODyS: "Based on 39 optical observations (of which 0 are rejected as outliers) from 2012-12-13.147 to 2012-12-21.278."
2012 XE133JPL Sentry16562083-210457.7e-08-6.62-7.020JPL: "Analysis based on 78 observations spanning 8.8349 days (2012-Dec-12.43361 to 2012-Dec-21.26854)." Diameter approximately 0.068 km. from mean, weighted H=23.5.
NEODyS16562083-209122.42e-08-7.11-7.390NEODyS: "Based on 78 optical observations (of which 0 are rejected as outliers) from 2012-12-12.434 to 2012-12-21.269."

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 22 December '12

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

1659Generated Traffic Report
1656Noted that JPL Sentry has updated its 2012 XE133 risk assessment - see above
Noted that NEODyS has updated its 2012 XE133 risk assessment - see above
Noted that NEODyS has updated its 2012 XK134 risk assessment - see above
Grabbed MPEC 2012-Y19 - Daily Orbit Update - see above