Contents  on 21 February '11


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 21 February '11

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 21 February '11

Minor Planet Electronic Circulars

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

MPEC 2011-D21 - "12:48 UT" - 2011 BZ59

<< DOU on 21 Feb. '11 >>  MPEC 2011-D20 - "07:06 UT" - Daily Orbit Update

Observers  on 21 February '11

Five observers appear in today's MPECs.

CodeObserver / observatory
H21Astronomical Research Obs. Westfield in Illinois, 20 in MPEC 2011-D20 -- 2011 CY7, 2011 CY46, 2011 CG33, 2011 CG2, 2011 BX10, 2011 BR15, 2011 BK24, 2011 BJ24, 2011 BC40, 2011 BA12, 2011 AO52, 2011 AN16, 2011 AM24, 2011 AL52, 2011 AG5, 2011 AF37, 2011 AA37, 2010 XZ67, 2010 XP51, 2010 TH19
H15ISON-NM Obs. in New Mexico, 3 in MPEC 2011-D20 -- 2011 CY46, 2011 CG2, 2011 BO59
D95Kurihara Obs. in Japan, 1 in MPEC 2011-D20 -- 4954
5682David Tholen's team on Mauna Kea in Hawaii, 1 in MPEC 2011-D21 -- 2011 BZ59
F51Pan-STARRS 1 in Hawaii, 1 in MPEC 2011-D21 -- 2011 BZ59
For a list of all participating observatories that have Web addresses, see A/CC's Observatory Links page.

Impact Risk Monitoring  on 21 February '11

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 CLOMON (backup) risk pages.





Notes for Today's Latest Risk Assessments
2011 BA12JPL Sentry1603R E M O V E DJPL: Risk listing removed at 1050 UTC.
2011 AG5NEODyS16032031-2058162.59e-04-2.06-2.111NEODyS: "Based on 119 optical observations (of which 0 are rejected as outliers) from 2011-01-08.268 to 2011-02-20.057."

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 21 February '11

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

1603Noted that NEODyS has updated its 2011 AG5 risk assessment - see above
Noted that JPL Sentry has removed 2011 BA12 as an impact risk - see above
Grabbed MPEC 2011-D20 - Daily Orbit Update - see above
Grabbed MPEC 2011-D21 - 2011 BZ59 - see above