Contents  on 25 April '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 25 April '09

The MPC's NEO Confirmation Page has 7 listings: 7 updated

When last checked at 1624 UTC today, the Minor Planet Center's Near Earth Object discovery Confirmation Page (NEOCP) had seven updated listings. Of these, three were "one nighters." The Tracking News counted a total of ten listings on the NEOCP at some point on this day.

New MPECs  on 25 April '09

Minor Planet Electronic Circulars

There was one MPEC posted this day from the International Astronomical Union's Minor Planet Center in Cambridge, Massachusetts.

<< DOU on 25 Apr. '09 >>  MPEC 2009-H54 - "06:09 UT" - Daily Orbit Update

Observers  on 25 April '09

Thirteen observing facilities appeared in this day's MPEC.

CodeObserver / observatory
B03Alter Satzberg Obs. in Austria, 1 in MPEC 2009-H54 -- 2003 SG170
A50Andrushivka Obs. in the Ukraine, 1 in MPEC 2009-H54 -- 177614
160Castelmartini Obs. in Italy, 3 in MPEC 2009-H54 -- 2009 HU44, 2009 HD, 2007 BT2
703Catalina Sky Survey (CSS) in Arizona, 6 in MPEC 2009-H54 -- 2009 CR2, 89355, 152931, 143651, 8566, 5011
E10Faulkes Telescope South in New South Wales, 4 in MPEC 2009-H54 -- 2009 HW44, 2009 HV44, 2009 HU44, 2009 HS44
B15Inastars Obs. in Germany, 1 in MPEC 2009-H54 -- 2002 LV
704LINEAR in New Mexico, 8 in MPEC 2009-H54 -- 85867, 36284, 35396, 155334, 143947, 7358, 5011, 3554
J75La Sagra Obs. in Spain, 3 in MPEC 2009-H54 -- 89958, 40329, 143947
G96Mt. Lemmon Survey (MLS) in Arizona, 7 in MPEC 2009-H54 -- 2009 HC, 2003 UN12, 2002 HF8, 1998 ST4, 36284, 200840, 7358
A20Sogel Obs. in Germany, 1 in MPEC 2009-H54 -- 25916
691Spacewatch 0.9m telescope in Arizona, 1 in MPEC 2009-H54 -- 2009 HV2
291Spacewatch 1.8m telescope in Arizona, 3 in MPEC 2009-H54 -- 2009 HC, 2009 HA21, 2000 TO64
B01Taunus Obs. in Germany, 1 in MPEC 2009-H54 -- 2009 HL21
For a list of all participating observatories that have Web addresses, see A/CC's Observatory Links page.

Impact Risk Monitoring  on 25 April '09

Summary Risk Table for Risk Assessments Updated Today   (last checks: NEODyS and JPL at 1624 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 HX51NEODyS14172010-20901165.64e-07-3.88-4.450NEODyS: "Based on 21 optical observations (of which 0 are rejected as outliers) from 2009/04/23.358 to 2009/04/24.354."
2009 HCJPL Sentry14172095-209741.0e-06-6.39-6.870JPL: "Analysis based on 71 observations spanning 7.0745 days (2009-Apr-17.23164 to 2009-Apr-24.3061)." Diameter approximately 0.036 km. from mean, weighted H=24.9.
99942 Apophis (2004 MN4)NEODyS16242036-2083171.98e-05-2.61-2.620NEODyS: "Based on 1000 optical observations (of which 5 are rejected as outliers) from 2004/03/15.108 to 2006/08/16.627, and also on seven radar data points on 2005/01/27, 2005/01/29, 2005/01/31, 2005/08/07 and 2006/05/06."

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 25 April '09

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

1624Noted that NEODyS has updated its 99942 Apophis (2004 MN4) risk assessment - see above
1417Noted that JPL Sentry has updated its 2009 HC risk assessment - see above
Noted that NEODyS has posted 2009 HX51 as an impact risk - see above
Grabbed MPEC 2009-H54 - Daily Orbit Update - see above