Contents  on 23 December '13

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 23 December '13

One object reported inside ten LD

One asteroid is reported to be possibly within ten lunar distances (LD) of our planet today. Returning 2011 YD29 is calculated with major uncertainty to enter ten LD, passing from 10.4 to 9.3 LD.

This report was generated at 1605 UTC with follow-up in today's DOU MPEC for departed radar target 2013 NJ.

Notes: Ten times the distance to the Moon (ten LD) has no astronomical significance but is a useful reporting boundary. 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 23 December '13

The MPC's NEO Confirmation Page has 15 listings

When last checked at 2359 UTC today, the Minor Planet Center's Near Earth Object discovery Confirmation Page (NEOCP) had fifteen objects listed. Of these, thirteen were "one nighters." So far The Tracking News has counted a total of 22 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 23 December '13

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 2013-Y22 - "22:49 UT" - 2013 YB

MPEC 2013-Y21 - "21:21 UT" - 2013 XN24

<< DOU on 23 Dec. '13 >>  MPEC 2013-Y20 - "14:02 UT" - Daily Orbit Update

Observers  on 23 December '13

Eighteen observers appear in today's MPECs.

CodeObserver / observatory
I99Blanquita Obs. in Spain, 3 in MPEC 2013-Y20 -- 2013 UR3, 251346, 162566
160Castelmartini Obs. in Italy, 5 in MPEC 2013-Y20 -- 2013 NJ, 2009 WZ104, 2008 TQ2, 2006 CT, 378610
703Catalina Sky Survey (CSS) in Arizona, 16 in MPECs 2013-Y20 & 2013-Y22 -- 2013 YB, 2013 XZ21, 2013 XX8, 2013 WC44, 2013 NJ, 2009 XZ1, 2006 WQ1, 2002 XS40, 55532, 380476, 363305, 29075, 162004, 137099, 12923, 9950
G48Doc Greiner Research Obs. Rancho Hildalgo in New Mexico, 1 in MPEC 2013-Y20 -- 2013 JB36
695^Spacewatch via Kitt Peak Natl. Obs. in Arizona, 1 in MPEC 2013-Y20 -- 2006 UK
H01Magdalena Ridge Obs. in New Mexico, 1 in MPEC 2013-Y21 -- 2013 XN24
5682David Tholen's team on Mauna Kea in Hawaii, 4 in MPEC 2013-Y20 -- 2013 XW3, 2013 XH4, 2013 XF22, 2013 WA44
213Montcabre Obs. in Spain, 1 in MPEC 2013-Y20 -- 2013 XA4
G96Mt. Lemmon Survey (MLS) in Arizona, 5 in MPEC 2013-Y20 -- 377097, 311066, 152742, 143651, 6178
A24New Millennium Obs. in Italy, 9 in MPEC 2013-Y20 -- 2010 XZ67, 89830, 55532, 53435, 251346, 21088, 162566, 138095, 137062
J43Oukaimeden Obs. in Morocco, 1 in MPEC 2013-Y20 -- 18109
F51Pan-STARRS 1 (PS1) in Hawaii, 10 in MPECs 2013-Y20 & 2013-Y21 -- 2013 XN24, 2003 WX25, 96315, 85709, 52760, 39565, 142464, 137099, 10165, 5863
D29Purple Mtn. Obs. Xuyi Station in China, 5 in MPEC 2013-Y20 -- 2013 TB80, 377097, 17511, 16834, 9950
H36Sandlot Obs. in Kansas, 2 in MPEC 2013-Y20 -- 2013 XY21, 2013 UG9
204Schiaparelli Obs. in Italy, 1 in MPEC 2013-Y21 -- 2013 XN24
J84South Obs. in England, 2 in MPEC 2013-Y20 -- 2013 XM24, 2009 XZ1
291Spacewatch 1.8m telescope in Arizona, 27 in MPECs 2013-Y20 & 2013-Y21 -- 2013 XZ20, 2013 XY21, 2013 XW3, 2013 XS3, 2013 XN24, 2013 XH4, 2013 XF22, 2013 XA22, 2013 WY67, 2013 WW45, 2013 WW44, 2013 WR67, 2013 WN67, 2013 WN, 2013 WM106, 2013 WH, 2013 WF108, 2013 WB44, 2013 UV10, 2013 US3, 2013 UP8, 2013 UG9, 2013 UG5, 2013 TG4, 2013 NP11, 2013 LM31, 2008 HY37
926Tenagra II Obs. in Arizona, 1 in MPEC 2013-Y21 -- 2013 XN24
For a list of all participating observatories that have Web addresses, see A/CC's Observatory Links page.

Impact Risk Monitoring  on 23 December '13

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
2013 XA22JPL Sentry1719R E M O V E DJPL: Risk listing removed at 1608 UTC.

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 23 December '13

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

2359Grabbed MPEC 2013-Y22 - 2013 YB - see above
2222Grabbed MPEC 2013-Y21 - 2013 XN24 - see above
1719Noted that JPL Sentry has removed 2013 XA22 as an impact risk - see above
1605Generated Traffic Report
1602Grabbed MPEC 2013-Y20 - Daily Orbit Update - see above