Contents  on 24 March '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 24 March '11

The MPC's NEO Confirmation Page has 2 listings: 2 updated

When last checked at 2359 UTC today, the Minor Planet Center's Near Earth Object discovery Confirmation Page (NEOCP) had two updated listings. Of these, one was a "one nighter."

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

New MPECs  on 24 March '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-F21 - "19:57 UT" - Comet P/2011 A1 (Larson)

<< DOU on 24 Mar. '11 >>  MPEC 2011-F20 - "07:07 UT" - Daily Orbit Update

Observers  on 24 March '11

Twelve observers appear in today's MPECs.

CodeObserver / observatory
J16An Carraig Obs. in Northern Ireland, 1 in MPEC 2011-F20 -- 4954
A74Bergen-Enkheim Obs. in Germany, 1 in MPEC 2011-F20 -- 2007 TB23
160Castelmartini Obs. in Italy, 2 in MPEC 2011-F20 -- 2011 CH71, 23187
807{Dan Reichart via Cerro Tololo Inter-American Obs. (CTIO) in Chile, 2 in MPEC 2011-F20 -- 2010 XK52, 20086
639Dresden Obs. in Germany, 1 in MPEC 2011-F20 -- 11885
A17Guidestar Obs. in Germany, 3 in MPEC 2011-F20 -- 2011 EW29, 2011 DS9, 2003 SC11
168Kourovskaya Obs. in Russia, 4 in MPEC 2011-F20 -- 36284, 137170, 3554, 3122
704LINEAR in New Mexico, 2 in MPEC 2011-F20 -- 2009 FT, 2007 EJ
644NEAT's Mt. Palomar telescope in southern California, 1 in MPEC 2011-F21 -- P/2011 A1
A24New Millennium Obs. in Italy, 15 in MPEC 2011-F20 -- 2009 DV42, 2009 BH81, 2002 TD60, 1999 TK12, 267136, 265196, 250614, 234341, 23183, 215167, 15745, 152889, 144332, 4401, 3554
691Spacewatch 0.9m telescope in Arizona, 1 in MPEC 2011-F21 -- P/2011 A1
291Spacewatch 1.8m telescope in Arizona, 6 in MPEC 2011-F20 -- 2011 EZ40, 2011 EL11, 2011 EJ47, 2011 CG22, 2011 BJ24, 2010 DA
For a list of all participating observatories that have Web addresses, see A/CC's Observatory Links page.

Impact Risk Monitoring  on 24 March '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 EL11NEODyS1503R E M O V E D-
JPL Sentry1503R E M O V E DJPL: Risk listing removed at 1052 UTC.
2010 EN44NEODyS15032027-202716.8e-10-7.41-7.410NEODyS: "Based on 11 optical observations (of which 0 are rejected as outliers) from 2010-03-11.868 to 2010-03-12.596."
2010 DG77NEODyS15032042-2090343.16e-06-5.66-6.360NEODyS: "Based on 10 optical observations (of which 0 are rejected as outliers) from 2010-02-19.176 to 2010-02-19.772."
JPL Sentry02182023-21111371.4e-06-5.55-6.250JPL: "Analysis based on 10 observations spanning .59543 days (2010-Feb-19.17573 to 2010-Feb-19.77116)." Diameter approximately 0.045 km. from mean, weighted H=24.5.

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 24 March '11

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

2000Grabbed MPEC 2011-F21 - Comet P/2011 A1 (Larson) - see above
1503Noted that NEODyS has updated its 2010 DG77 risk assessment - see above
Noted that NEODyS has updated its 2010 EN44 risk assessment - see above
Noted that JPL Sentry has removed 2011 EL11 as an impact risk - see above
Noted that NEODyS has removed 2011 EL11 as an impact risk - see above
Grabbed MPEC 2011-F20 - Daily Orbit Update - see above
0218Noted that JPL Sentry has updated its 2010 DG77 risk assessment - see above