Contents  on 28 December '09


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.

NEOCP Activity  on 28 December '09

The MPC's NEO Confirmation Page is currently empty

The NEOCP is currently empty and hasn't been noted by The Tracking News as being active yet today (checked at 2359 UTC). It was last noted active yesterday.

New MPECs  on 28 December '09

Minor Planet Electronic Circulars

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

<< DOU on 28 Dec. '09 >>  MPEC 2009-Y54 - "07:13 UT" - Daily Orbit Update

Observers  on 28 December '09

Twelve observing facilities appear in today's MPEC.

CodeObserver / observatory
448Desert Moon Obs. in New Mexico, 5 in MPEC 2009-Y54 -- 2009 YG, 2009 WE253, 2009 TB8, 2008 UL90, 143947
639Dresden Obs. in Germany, 1 in MPEC 2009-Y54 -- 2009 XD
J95Great Shefford Obs. in England, 1 in MPEC 2009-Y54 -- 2009 WL1
D95Kurihara Obs., 1 in MPEC 2009-Y54 -- 4015
B33Libbiano Obs. in Italy, 4 in MPEC 2009-Y54 -- 2009 XR2, 2007 UR3, 2006 KZ37, 2002 AP7
560Madonna di Dossobuono Obs. in Italy, 2 in MPEC 2009-Y54 -- 2009 XR2, 2007 UR3
932McCarthy Obs. in Connecticut, 6 in MPEC 2009-Y54 -- 2009 YF, 2009 XO, 2009 XD, 2009 WZ104, 2009 NA, 2008 UL90
A53Peschiera del Garda Obs. in Italy, 5 in MPEC 2009-Y54 -- 2009 XT6, 2009 XR2, 2007 MK13, 2005 TY51, 2002 WP
D29Purple Mtn. Obs. Xuyi Station in China, 1 in MPEC 2009-Y54 -- 10150
291Spacewatch 1.8m telescope in Arizona, 5 in MPEC 2009-Y54 -- 2009 YQ, 2009 YG, 2005 WE, 2005 AY28, 225312
A48Verona Obs. in Italy, 2 in MPEC 2009-Y54 -- 2009 XD, 5646
H47Vicksburg Obs. in Mississippi, 1 in MPEC 2009-Y54 -- 5131
For a list of all participating observatories that have Web addresses, see A/CC's Observatory Links page.

Impact Risk Monitoring  on 28 December '09

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. Beginning Jan. 22nd, both are also posting impact solutions beyond 100 years for a few objects.
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
2009 YGJPL Sentry17202033-209964.5e-06-1.84-2.101JPL: "Analysis based on 45 observations spanning 10.092 days (2009-Dec-17.42051 to 2009-Dec-27.51294)." Diameter approximately 0.776 km. from mean, weighted H=18.2.
NEODyS15202033-208063.08e-06-1.92-2.101NEODyS: "Based on 45 optical observations (of which 0 are rejected as outliers) from 2009/12/17.421 to 2009/12/27.514. NOTE: The Virtual Impactor in 2050/02/06.089 ... is rated as Torino Scale 1."
2009 XOJPL Sentry15202038-204522.2e-07-4.16-4.400JPL: "Analysis based on 114 observations spanning 19.022 days (2009-Dec-09.152 to 2009-Dec-28.17429)." Diameter approximately 0.300 km. from mean, weighted H=20.2.
NEODyS1520208313.51e-09-6.32-6.320NEODyS: "Based on 114 optical observations (of which 0 are rejected as outliers) from 2009/12/09.153 to 2009/12/28.175."

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 '09

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

1720Noted that JPL Sentry has updated its 2009 YG risk assessment - see above
1520Noted that JPL Sentry has reposted 2009 XO as an impact risk - see above
Noted that NEODyS has updated its 2009 XO risk assessment - see above
Noted that NEODyS has updated its 2009 YG risk assessment - see above
Grabbed MPEC 2009-Y54 - Daily Orbit Update - see above