Contents  on 8 March '12

Asteroid/Comet Connection (A/CC) Resources:

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.

Traffic Report  on 8 March '12

Five objects reported inside ten LD

Five visitors are reported flying inside ten lunar distances (LD) of Earth today. Radar target 2012 DH54 enters Earth's Hill sphere. Further out, risk-listed radar target 2012 DW60 moves in from 6.31 to 5.18 LD, 2012 EA heads away from 5.87 to 6.91 LD, 2012 EM1 is outbound from 7.81 to 8.24 LD, and unobserved 2008 EJ85 is calculated to be moving away from 9.3 to 9.6 LD*.

Up next, 2007 HV4 arrives inside ten LD on April 14th.

This report was posted at 1639 UTC with follow-up in today's DOU MPEC for 2012 EM1, 2012 DW60, and 2012 DH54.

Notes: Ten times the distance to the Moon (ten LD) has no astronomical significance but is a useful reporting boundary. Earth's Hill sphere (of gravitational influence) is estimated to extend out to around 3.89 LD. Distances are interpreted by A/CC from JPL Horizons data. "LD*" indicates some passage uncertainty. See also today's timeline, current sky chart and object details (alt-details), and ephemerides.

NEOCP Activity  on 8 March '12

The MPC's NEO Confirmation Page has 1 listing

When last checked at 2359 UTC today, the Minor Planet Center's Near Earth Object discovery Confirmation Page (NEOCP) had one object listed.

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 8 March '12

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 8 Mar. '12 >>  MPEC 2012-E42 - "06:04 UT" - Daily Orbit Update

Observers  on 8 March '12

Six observers appear in today's MPEC.

CodeObserver / observatory
H21Astronomical Research Obs. Westfield in Illinois, 1 in MPEC 2012-E42 -- 155336
807|Robert Holmes in Illinois via Cerro Tololo Inter-American Obs. (CTIO) in Chile, 7 in MPEC 2012-E42 -- 2012 EM1, 2012 DW60, 2012 BZ76, 2012 AT22, 2011 XE1, 2009 UW18, 2008 EY5
C73Galati Obs. in Romania, 8 in MPEC 2012-E42 -- 2012 CD29, 2012 BT23, 2011 SL102, 2004 QJ7, 89959, 162186, 137925, 101873
J95Great Shefford Obs. in England, 2 in MPEC 2012-E42 -- 2012 DW60, 2012 DH54
A24New Millennium Obs. in Italy, 33 in MPEC 2012-E42 -- 2012 CD29, 2012 BC20, 2012 AA11, 2011 YV15, 2011 XO3, 2011 WV134, 2010 SV3, 2009 AV, 2006 AL8, 2004 QJ7, 85839, 32906, 311554, 302830, 29075, 263976, 24475, 21088, 209924, 162186, 154269, 143651, 138524, 138013, 137805, 9400, 8567, 6455, 3554, 3352, 1627, 1620, 1036
J41Raheny Obs. in Ireland, 2 in MPEC 2012-E42 -- 2012 DX75, 2012 DF61
For a list of all participating observatories that have Web addresses, see A/CC's Observatory Links page.

Impact Risk Monitoring  on 8 March '12

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 CLOMON2 risk pages.





Notes for Today's Latest Risk Assessments
2012 DW60JPL Sentry22162069-21111394.6e-04-4.40-4.800JPL: "Analysis based on 53 observations spanning 7.5837 days (2012-Feb-29.49427 to 2012-Mar-08.07794)." Diameter approximately 0.018 km. from mean, weighted H=26.4.
NEODyS16382065-2090531.91e-04-4.76-5.050NEODyS: "Based on 53 optical observations (of which 0 are rejected as outliers) from 2012-02-29.495 to 2012-03-08.079."
2012 DA14JPL Sentry22162020-2042256.7e-05-3.58-4.020JPL: "Analysis based on 112 observations spanning 12.126 days (2012-Feb-23.03431 to 2012-Mar-06.15983)." Diameter approximately 0.044 km. from mean, weighted H=24.4.
NEODyS16382020-20903544.22e-04-3.09-3.870NEODyS: "Based on 115 optical observations (of which 3 are rejected as outliers) from 2012-02-23.029 to 2012-03-06.161."
2011 AX22NEODyS1638R E M O V E D-

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 8 March '12

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

2216Noted that JPL Sentry has updated its 2012 DA14 risk assessment - see above
Noted that JPL Sentry has updated its 2012 DW60 risk assessment - see above
1639Posted Traffic Report
1638Noted that NEODyS has removed 2011 AX22 as an impact risk - see above
Noted that NEODyS has updated its 2012 DA14 risk assessment - see above
Noted that NEODyS has updated its 2012 DW60 risk assessment - see above
Grabbed MPEC 2012-E42 - Daily Orbit Update - see above