Contents  on 28 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 28 December '13

Two objects reported inside ten LD

Two visitors are reported moving within ten lunar distances (LD) of our planet today. Unobserved 2011 YD29 is calculated to come it closest to Earth on this passage, reaching 6.1 LD at 1534 UT but with an uncertainty of +/- 17.4833 hours. And risk-listed intruder 2013 YB leaves ten LD, moving from 9.13 to 11.17 LD.

Coming our way next, 2013 YL2 arrives inside ten LD on January 1st.

This report was generated at 1826 UTC with new discoveries 2013 YL2 (MPEC) and departed 2013 YQ2 (MPEC), both announced late the day before yesterday, and with follow-up in the DOU MPEC yesterday for departed objects 2013 YD, radar target 2013 NJ, and risk-listed 2013 WZ44. Today's DOU MPEC has follow-up for 2013 YQ2, 2013 YL2, 2013 YD, and 2013 NJ. We didn't post a Traffic Report yesterday as we were unable to access the necessary JPL Horizons data.

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 28 December '13

The MPC's NEO Confirmation Page has 16 listings

When last checked at 2359 UTC today, the Minor Planet Center's Near Earth Object discovery Confirmation Page (NEOCP) had sixteen objects listed. Of these, eight were "one nighters." So far The Tracking News has counted a total of 26 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 28 December '13

Minor Planet Electronic Circulars

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

MPEC 2013-Y54 - "18:54 UT" - 2010 CL18

MPEC 2013-Y53 - "18:49 UT" - 2009 BJ58

<< DOU on 28 Dec. '13 >>  MPEC 2013-Y52 - "14:03 UT" - Daily Orbit Update

MPEC 2013-Y51 - "03:15 UT" - 2010 XD11

Observers  on 28 December '13

A total of 27 observers appear in today's MPECs.

CodeObserver / observatory
H21Astronomical Research Obs. Westfield in Illinois, 7 in MPEC 2013-Y52 -- 2013 YT2, 2013 YR2, 2013 YF, 2013 YE, 2013 YD, 2013 YC, 2002 WY12
C77Bernezzo Obs. in Italy, 1 in MPEC 2013-Y52 -- 2013 YZ13
703Catalina Sky Survey (CSS) in Arizona, 2 in MPEC 2013-Y52 -- 2013 YL2, 35432
807|Robert Holmes in Illinois via Cerro Tololo Inter-American Obs. (CTIO) in Chile, 9 in MPEC 2013-Y52 -- 2013 YY13, 2013 YF, 2013 YC14, 2013 SK19, 2013 SF, 2009 TG10, 2008 XM, 90147, 38071
448Desert Moon Obs. in New Mexico, 4 in MPEC 2013-Y52 -- 2013 TH5, 2004 XO14, 377732, 265661
113Drebach Obs. in Germany, 1 in MPEC 2013-Y52 -- 2010 XZ67
J95Great Shefford Obs. in England, 2 in MPEC 2013-Y52 -- 2013 YC14, 2013 YB14
C43Hoyerswerda Obs. in Germany, 1 in MPEC 2013-Y52 -- 2013 YB14
H15ISON-NM Obs. in New Mexico, 2 in MPEC 2013-Y52 -- 2013 NJ, 363305
K48Keyhole Obs., 2 in MPEC 2013-Y52 -- 294739, 251346
I36Los Campitos Obs. in Argentina, 1 in MPEC 2013-Y52 -- 2013 XV8
D54MASTER-II Obs. Blagoveshchensk in Russia, 1 in MPEC 2013-Y52 -- 361071
C41MASTER-II Obs. Kislovodsk in Russia, 1 in MPEC 2013-Y52 -- 249595
474Mt. John Obs. in New Zealand, 3 in MPEC 2013-Y52 -- 2013 WT44, 2013 WC44, 2013 PD21
G96Mt. Lemmon Survey (MLS) in Arizona, 4 in MPEC 2013-Y52 -- 2013 XG22, 2001 QC34, 311066, 6178
C23Olmen Obs. in Belgium, 4 in MPEC 2013-Y52 -- 2013 XA4, 2010 XZ67, 377097, 251346
I41Palomar Transient Factory in southern California, 1 in MPEC 2013-Y52 -- 2005 LS3
H45Petit Jean Mtn. South Obs. (PJMSO) in Arkansas, 6 in MPEC 2013-Y52 -- 2013 WT45, 2013 UR3, 2013 TB80, 2009 WE253, 251346, 21088
D29Purple Mtn. Obs. Xuyi Station in China, 6 in MPEC 2013-Y52 -- 2013 TH5, 2013 NX23, 2011 CQ4, 29075, 162361, 162004
461SZTE Asteroid Program in Hungary, 1 in MPEC 2013-Y52 -- 2010 XZ67
434San Benedetto Po Obs. in Italy, 1 in MPEC 2013-Y52 -- 361071
K33San Defendente Obs., 1 in MPEC 2013-Y52 -- 2013 XA4
H36Sandlot Obs. in Kansas, 3 in MPEC 2013-Y52 -- 2013 YG, 2013 XM24, 2013 XA22
G403Tony Evans in Portugal via Canary Islands Obs. in the Canary Islands, 1 in MPEC 2013-Y52 -- 2013 YQ2
G404Don Cranford, Jr. in North Carolina via Canary Islands Obs. in the Canary Islands, 1 in MPEC 2013-Y52 -- 2013 XV8
691Spacewatch 0.9m telescope in Arizona, 5 in MPEC 2013-Y52 -- 2013 XV8, 2013 XA22, 2013 LM31, 307564, 22753
291Spacewatch 1.8m telescope in Arizona, 23 in MPECs 2013-Y52 & 2013-Y54 -- 2013 YY13, 2013 YT2, 2013 YC, 2013 XU3, 2013 XH4, 2013 WT67, 2013 WR67, 2013 UV10, 2013 UP8, 2013 UG5, 2013 TG4, 2013 QG17, 2013 PV2, 2013 NP11, 2013 LM31, 2011 VV5, 2010 CL18, 2009 KE3, 2008 VN, 2006 TC, 2003 FS2, 2002 WY12, 215188
926Tenagra II Obs. in Arizona, 13 in MPECs 2013-Y51, 2013-Y52 & 2013-Y53 -- 2013 YZ13, 2013 YY13, 2013 YT2, 2013 YQ2, 2013 YM2, 2013 YL2, 2013 YG, 2013 YF, 2013 YC14, 2013 YB14, 2013 YA14, 2010 XD11, 2009 BJ58
For a list of all participating observatories that have Web addresses, see A/CC's Observatory Links page.

Impact Risk Monitoring  on 28 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 YCJPL Sentry18122064-206838.9e-07-3.73-3.740JPL: "Analysis based on 40 observations spanning 5.0559 days (2013-Dec-23.16077 to 2013-Dec-28.21663)." Diameter approximately 0.180 km. from mean, weighted H=21.3.
NEODyS18122037-206828.87e-08-4.46-4.570NEODyS: "Based on 40 optical observations (of which 0 are rejected as outliers) from 2013-12-23.162 to 2013-12-28.217."

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 28 December '13

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

2002Grabbed MPEC 2013-Y54 - 2010 CL18 - see above
1900Grabbed MPEC 2013-Y53 - 2009 BJ58 - see above
1826Generated Traffic Report
1812Noted that JPL Sentry has updated its 2013 YC risk assessment - see above
Noted that NEODyS has updated its 2013 YC risk assessment - see above
1547Grabbed MPEC 2013-Y52 - Daily Orbit Update - see above
0518Grabbed MPEC 2013-Y51 - 2010 XD11 - see above