Contents  on 31 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 31 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 2358 UTC). It was last noted active on December 27th.

New MPECs  on 31 December '09

Minor Planet Electronic Circulars

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

MPEC 2009-Y65 - "14:28 UT" - 2006 JN6

<< DOU on 31 Dec. '09 >>  MPEC 2009-Y64 - "07:11 UT" - Daily Orbit Update

Observers  on 31 December '09

Six observing facilities appear in today's MPECs.

CodeObserver / observatory
H21Astronomical Research Obs. Westfield (ARO Westfield) in Illinois, 13 in MPEC 2009-Y64 -- 2009 YG, 2009 XO, 2009 UV18, 2007 MK13, 2006 AO4, 2005 MC, 2004 XK4, 2004 TB18, 2004 AR1, 2002 YN2, 1985 WA, 159454, 10165
168Kourovskaya Obs. in Russia, 4 in MPEC 2009-Y64 -- 35396, 22771, 4015, 3554
5682David Tholen's team on Mauna Kea in Hawaii, 1 in MPEC 2009-Y65 -- 2006 JN6
932McCarthy Obs. in Connecticut, 1 in MPEC 2009-Y64 -- 6455
583Odessa-Mayaki Obs., 1 in MPEC 2009-Y64 -- 2007 MK13
D90`Kevin Hills in England via RAS Obs. Moorook in South Australia, 1 in MPEC 2009-Y64 -- 2008 YZ32
For a list of all participating observatories that have Web addresses, see A/CC's Observatory Links page.

Impact Risk Monitoring  on 31 December '09

Summary Risk Table for Risk Assessments Updated Today   (last checks: NEODyS and JPL at 2358 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 Sentry16002033-209961.1e-06-2.63-2.970JPL: "Analysis based on 49 observations spanning 12.087 days (2009-Dec-17.42051 to 2009-Dec-29.507266)." Diameter approximately 0.760 km. from mean, weighted H=18.3.
NEODyS16002033-208855.88e-07-2.81-3.260NEODyS: "Based on 49 optical observations (of which 0 are rejected as outliers) from 2009/12/17.421 to 2009/12/29.508."
2009 XOJPL Sentry16002038-209433.2e-07-4.03-4.320JPL: "Analysis based on 122 observations spanning 20.249 days (2009-Dec-09.152 to 2009-Dec-29.40079)." Diameter approximately 0.300 km. from mean, weighted H=20.2.
NEODyS16002038-204522.85e-07-4.05-4.330NEODyS: "Based on 122 optical observations (of which 0 are rejected as outliers) from 2009/12/09.153 to 2009/12/29.402."

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 31 December '09

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

1600Noted that JPL Sentry has updated its 2009 XO risk assessment - see above
Noted that NEODyS has updated its 2009 XO risk assessment - see above
Noted that JPL Sentry has updated its 2009 YG risk assessment - see above
Noted that NEODyS has updated its 2009 YG risk assessment - see above
Grabbed MPEC 2009-Y64 - Daily Orbit Update - see above
Grabbed MPEC 2009-Y65 - 2006 JN6 - see above