Contents  on 20 December '07


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 this year 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.

NEOCP Activity  on 20 December '07

The MPC's NEO Confirmation Page has 7 listings: 3 new, 4 updated

When last checked at 2354 UTC today, the Minor Planet Center's NEO discovery Confirmation Page (NEOCP) had three new and four updated listings. Of these, five were "one nighters." So far The Tracking News has counted a total of ten objects listed on the NEOCP at some point today.

To learn how observers use the NEOCP, see the Practical guide on how to observe NEOCP object by Birtwhistle et al. at Suno Observatory.

New MPECs  on 20 December '07

Minor Planet Electronic Circulars

As of last check at 2354 UTC, there have been seven MPECs issued today from the International Astronomical Union's Minor Planet Center in Cambridge, Massachusetts.

MPEC 2007-Y39 - "15:16 UT" - PHAs

MPEC 2007-Y38 - "15:16 UT" - Unusual Minor Planets

MPEC 2007-Y37 - "15:16 UT" - Amors

MPEC 2007-Y36 - "15:16 UT" - Atens and Apollos

MPEC 2007-Y35 - "15:11 UT" - Distant Minor Planets

MPEC 2007-Y34 - "14:44 UT" - Observable Comets

<< DOU on 20 Dec. '07 >>  MPEC 2007-Y33 - "07:07 UT" - Daily Orbit Update

Observers  on 20 December '07

Nineteen observing facilities appear in today's MPEC.

CodeObserver / observatory
834AAAA Buenos Aires Obs. in Argentina, 1 in MPEC 2007-Y33 -- 2007 XH16
H55Astronomical Research Obs. (ARO) in Illinois, 9 in MPEC 2007-Y33 -- 2007 YX1, 2007 YF, 2007 YB2, 2007 XN3, 2007 WW4, 2007 VX7, 2007 VR183, 2007 RA9, 2006 WX1
J51Atlante Obs. in the Canary Islands, 2 in MPEC 2007-Y33 -- 2002 XY4, 5131
A74Bergen-Enkheim Obs. in Germany, 1 in MPEC 2007-Y33 -- 2007 EH88
B09Capannoli Obs. in Italy, 3 in MPEC 2007-Y33 -- 2007 YH, 2007 SP6, 2002 XY4
703Catalina Sky Survey in Arizona, 1 in MPEC 2007-Y33 -- 2007 GS3
448Desert Moon Obs. in New Mexico, 5 in MPEC 2007-Y33 -- 2007 XY9, 2007 XF25, 2007 XC10, 2007 VH184, 153415
A17Guidestar Obs. in Germany, 2 in MPEC 2007-Y33 -- 2007 YN1, 140288
704LINEAR in New Mexico, 4 in MPEC 2007-Y33 -- 2007 WF55, 2007 VQ4, 2007 SP6, 1620
H01Magdalena Ridge Obs. in New Mexico, 1 in MPEC 2007-Y33 -- 2007 WD5
711McDonald Obs. in Texas, 2 in MPEC 2007-Y33 -- 2007 XK11, 2007 TG15
G96Mt. Lemmon Survey in Arizona, 1 in MPEC 2007-Y33 -- 1998 YM4
H45Petit Jean Mtn. South Obs. (PJMSO) in Arkansas, 14 in MPEC 2007-Y33 -- 2007 YZ, 2007 YK, 2007 YF1, 2007 XF25, 2007 WV3, 2007 SP6, 2007 EH88, 2005 WJ56, 2005 TU45, 1994 AW1, 154347, 153591, 3691, 1620
233San Vito Obs. in Italy, 1 in MPEC 2007-Y33 -- 2003 BH84
691Spacewatch 0.9m telescope in Arizona, 9 in MPEC 2007-Y33 -- 2007 YG, 2007 XF25, 2007 XB10, 2007 QE3, 2007 OG3, 85628, 25916, 144411, 138947
291Spacewatch 1.8m telescope in Arizona, 6 in MPEC 2007-Y33 -- 2007 WU4, 2007 TG1, 2005 EJ225, 2004 FU4, 2002 AE9, 1999 RM45
F85Tiki Obs. in Tahiti, 1 in MPEC 2007-Y33 -- 2007 XH16
6967Tim Spahr via Whipple Obs. in Arizona, 6 in MPEC 2007-Y33 -- 2007 XJ20, 2007 XB10, 2007 WB, 2007 VF191, 2007 NS4, 2004 NC9
198Wildberg Obs. in Germany, 1 in MPEC 2007-Y33 -- 170891

Impact Risk Monitoring  on 20 December '07

Summary Risk Table for Risk Assessments Updated Today   (last checks: NEODyS and JPL at 2354 UTC)
See the CRT page for a list of all objects rated recently as risks.
Note that the time horizon for JPL is 100 years from today and for NEODyS is now usually the year 2090.
For the latest official risk assessments, and for explanations of the terminology, see the JPL NEO Program Sentry and NEODyS CLOMON (backup) risk pages.





Notes for Today's Latest Risk Assessments
2007 YB2JPL Sentry14082016-21061151.2e-07-3.23-4.220JPL: "Analysis based on 18 observations spanning 1.1144 days (2007-Dec-18.34552 to 2007-Dec-19.45988)." Diameter approximately 0.857 km. from mean, weighted H=18.0.
NEODyS14082026-2089101.79e-08-4.07-4.480NEODyS: "Based on 18 optical observations (of which 0 are rejected as outliers) from 2007/12/18.346 to 2007/12/19.461."
2007 YN1NEODyS1408R E M O V E D
2007 YFJPL Sentry1408R E M O V E DJPL: Risk listing removed at 1325 UTC.
2007 XK11JPL Sentry15222064-210121.1e-07-4.32-4.380JPL: "Analysis based on 46 observations spanning 13.079 days (2007-Dec-06.0886 to 2007-Dec-19.16764)." Diameter approximately 0.495 km. from mean, weighted H=19.2.
NEODyS1408206418.62e-08-4.37-4.370NEODyS: "Based on 47 optical observations (of which 1 are rejected as outliers) from 2007/12/06.089 to 2007/12/19.168."

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 20 December '07

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

1558Grabbed MPEC 2007-Y37 - Amors - see above
Grabbed MPEC 2007-Y38 - Unusual Minor Planets - see above
Grabbed MPEC 2007-Y39 - PHAs - see above
1522Noted that JPL Sentry has updated its 2007 XK11 risk assessment - see above
Grabbed MPEC 2007-Y34 - Observable Comets - see above
Grabbed MPEC 2007-Y35 - Distant Minor Planets - see above
Grabbed MPEC 2007-Y36 - Atens and Apollos - see above
1408Noted that NEODyS has updated its 2007 XK11 risk assessment - see above
Noted that JPL Sentry has updated its 2007 YB2 risk assessment - see above
Noted that NEODyS has posted 2007 YB2 as an impact risk - see above
Noted that JPL Sentry has removed 2007 YF as an impact risk - see above
Noted that NEODyS has removed 2007 YN1 as an impact risk - see above
Grabbed MPEC 2007-Y33 - Daily Orbit Update - see above