Contents  on 10 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 10 December '13

One object reported inside ten LD

There is one object reported moving within ten lunar distances (LD) of our planet today. Within Earth's Hill sphere, risk-listed radar target 2013 XY8 is inbound from 3.58 to 2.20 LD.

This report was generated at 1556 UTC with follow-up in today's DOU MPEC for 2013 XY8 and 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. 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.

Radar Astrometry  on 10 December '13

Radar observation of one object

The JPL Solar System Dynamics Group Radar Astrometry database has added or updated the following small-body radar observing work:

Data update noted at 2247 UTC when the database was dated 10 Dec.

NEOCP Activity  on 10 December '13

The MPC's NEO Confirmation Page has 28 listings

When last checked at 2358 UTC today, the Minor Planet Center's Near Earth Object discovery Confirmation Page (NEOCP) had 28 objects listed. Of these, fourteen were "one nighters." So far The Tracking News has counted a total of 38 listings on the NEOCP today.

New MPECs  on 10 December '13

Minor Planet Electronic Circulars

As of last check at 2358 UTC, there have been four MPECs posted today from the International Astronomical Union's Minor Planet Center in Cambridge, Massachusetts.

MPEC 2013-X52 - "21:29 UT" - 2013 XH10

MPEC 2013-X51 - "21:24 UT" - 2013 XG10

MPEC 2013-X50 - "21:07 UT" - 2013 XB10

<< DOU on 10 Dec. '13 >>  MPEC 2013-X49 - "14:03 UT" - Daily Orbit Update

Observers  on 10 December '13

A total of 28 observers appear in today's MPECs.

CodeObserver / observatory
C77Bernezzo Obs. in Italy, 1 in MPEC 2013-X49 -- 2013 XY8
160Castelmartini Obs. in Italy, 2 in MPEC 2013-X49 -- 2010 CL19, 251346
703Catalina Sky Survey (CSS) in Arizona, 6 in MPEC 2013-X49 -- 2013 WC44, 138852, 137099, 9950, 6178, 3988
807|Robert Holmes in Illinois via Cerro Tololo Inter-American Obs. (CTIO) in Chile, 13 in MPEC 2013-X49 -- 2013 XY9, 2013 XV8, 2013 XU3, 2013 VK5, 2013 TS4, 2010 DW1, 2008 YV148, 2007 RN7, 53426, 302156, 224926, 142561, 138925
970Chelmsford Obs. in England, 1 in MPEC 2013-X49 -- 2013 XY8
Z65Corgas Obs., 4 in MPEC 2013-X49 -- 2010 CL19, 361071, 142781, 1627
958Dax Obs. in France, 1 in MPEC 2013-X51 -- 2013 XG10
448Desert Moon Obs. in New Mexico, 5 in MPEC 2013-X49 -- 2009 WE253, 88213, 189263, 163696, 155140
J27El Guijo Obs. in Spain, 4 in MPEC 2013-X49 -- 2013 UR3, 85818, 377097, 9950
253Goldstone DSS-14 70m antenna in southern California, 1 in radar -- 2013 XY8
J95Great Shefford Obs. in England, 1 in MPEC 2013-X49 -- 2013 XY8
A17Guidestar Obs. in Germany, 1 in MPEC 2013-X49 -- 2013 XZ9
130Lumezzane Obs. in Italy, 13 in MPEC 2013-X49 -- 2013 VY13, 2013 VD13, 2013 TV135, 2010 CL19, 2009 WE253, 2008 HO3, 39565, 377097, 265661, 142563, 141079, 9950, 8201
H01Magdalena Ridge Obs. (MRO) in New Mexico, 3 in MPECs 2013-X50, 2013-X51 & 2013-X52 -- 2013 XH10, 2013 XG10, 2013 XB10
568=program code "=" on Mauna Kea in Hawaii, 1 in MPEC 2013-X50 -- 2013 XB10
C91Montevenere Obs., 2 in MPEC 2013-X49 -- 251346, 12711
G96Mt. Lemmon Survey (MLS) in Arizona, 6 in MPECs 2013-X49 & 2013-X52 -- 2013 XH10, 2013 TB80, 2002 HF8, 22753, 137099, 6178
644NEAT's Mt. Palomar telescope in southern California, 1 in MPEC 2013-X49 -- 2012 FR62
F51Pan-STARRS 1 (PS1) in Hawaii, 2 in MPECs 2013-X50 & 2013-X51 -- 2013 XG10, 2013 XB10
D29Purple Mtn. Obs. Xuyi Station in China, 1 in MPEC 2013-X49 -- 2013 UR3
Y00SONEAR Obs. in Brazil, 1 in MPEC 2013-X49 -- 2013 XY8
B04Saint-Barthelemy Obs. in Italy, 1 in MPEC 2013-X49 -- 2013 XY8
H36Sandlot Obs. in Kansas, 1 in MPEC 2013-X49 -- 2013 XY8
204Schiaparelli Obs. in Italy, 1 in MPEC 2013-X51 -- 2013 XG10
291Spacewatch 1.8m telescope in Arizona, 8 in MPECs 2013-X49 & 2013-X50 -- 2013 XY8, 2013 XB10, 2013 WU44, 2013 WT45, 2013 WR67, 2013 WR44, 2013 WN67, 2013 WF108
I93St. Pardon de Conques Obs. in France, 1 in MPEC 2013-X49 -- 2013 XY8
926Tenagra II Obs. in Arizona, 1 in MPEC 2013-X51 -- 2013 XG10
I45W Crucis Obs. in Argentina, 1 in MPEC 2013-X49 -- 2013 NJ
For a list of all participating observatories that have Web addresses, see A/CC's Observatory Links page.

Impact Risk Monitoring  on 10 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 XY8NEODyS15552073-211061.21e-04-4.07-4.070NEODyS: "Based on 60 optical observations (of which 4 are rejected as outliers) from 2013-12-07.171 to 2013-12-08.763."
JPL Sentry02052091-209524.2e-04-3.52-3.520JPL #2 for the day: "Analysis based on 117 observations spanning 2.8089 days (2013-Dec-07.17005 to 2013-Dec-09.97899)." Diameter approximately 0.040 km. from mean, weighted H=24.7.
2013 XE2NEODyS15552027-2080171.17e-08-4.00-4.670NEODyS: "Based on 25 optical observations (of which 0 are rejected as outliers) from 2013-12-03.627 to 2013-12-05.610."
2013 WR67JPL Sentry1614R E M O V E DJPL: Risk listing removed at 1601 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 10 December '13

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

2247Noted Radar Astrometry database update - see above
2200Grabbed MPEC 2013-X50 - 2013 XB10 - see above
Grabbed MPEC 2013-X51 - 2013 XG10 - see above
Grabbed MPEC 2013-X52 - 2013 XH10 - see above
1614Noted that JPL Sentry has removed 2013 WR67 as an impact risk - see above
1556Generated Traffic Report
1555Noted that NEODyS has posted 2013 XE2 as an impact risk - see above
Noted that NEODyS has posted 2013 XY8 as an impact risk - see above
Grabbed MPEC 2013-X49 - Daily Orbit Update - see above
0205Noted that JPL Sentry has updated its 2013 XY8 risk assessment - see above
0018Noted that JPL Sentry has updated its 2013 XY8 risk assessment - see above