Contents  on 25 February '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 25 February '12

Five objects reported inside ten LD

There are five asteroids reported traveling inside ten lunar distances (LD) of our planet today. Within Earth's Hill sphere, risk-listed 2012 CS46 may be coming its closest to Earth this time around, reaching 2.7 LD at 2305 UTC with an uncertainty of 16.8500 hours. Further out, radar target 2012 DX13 comes its closest to Earth this time, reaching 4.85 LD at 1518 UTC, 2012 DX exits ten LD, traveling from 7.94 to 10.26 LD, 2012 DZ exits ten LD, moving from 7.95 to 11.52 LD, and 2012 DY travels from 9.32 to 9.85 LD.

Coming toward Earth, 2008 EJ85 arrives inside ten LD on March 4th.

This report was posted at 1540 UTC with follow-up in today's DOU MPEC for 2012 DA14, 2012 DY13, and 2012 DX13.

Notes: 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. See also today's timeline, current sky chart and object details (alt-details), and ephemerides.

NEOCP Activity  on 25 February '12

The MPC's NEO Confirmation Page has 49 listings

When last checked at 2359 UTC today, the Minor Planet Center's Near Earth Object discovery Confirmation Page (NEOCP) had 49 objects listed. Of these, eleven were "one nighters." So far The Tracking News has counted a total of 54 listings on the NEOCP today.

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 25 February '12

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 2012-D61 - "23:53 UT" - 2010 DF1

<< DOU on 25 Feb. '12 >>  MPEC 2012-D60 - "06:04 UT" - Daily Orbit Update

Observers  on 25 February '12

Eighteen observers appear in today's MPECs.

CodeObserver / observatory
A81Balzaretto Obs. in Italy, 3 in MPEC 2012-D60 -- 2012 BT23, 2012 AA11, 209924
B75Betelgeuse Station in Italy, 3 in MPEC 2012-D60 -- 2012 DX13, 2012 CD29, 2012 BJ134
703Catalina Sky Survey (CSS) in Arizona, 10 in MPEC 2012-D60 -- 2012 DX13, 2012 BK77, 2011 SL102, 2008 CH1, 2008 AV28, 138155, 137925, 101873, 1917, 1620
807|Robert Holmes in Illinois via Cerro Tololo Inter-American Obs. in Chile, 1 in MPEC 2012-D60 -- 2012 DO
G48Doc Greiner Research Obs. Rancho Hildalgo (DGRO-RH) in New Mexico, 2 in MPEC 2012-D60 -- 2012 DZ13, 2012 DX13
719Etscorn Obs. in New Mexico, 1 in MPEC 2012-D60 -- 137170
J95Great Shefford Obs. in England, 1 in MPEC 2012-D61 -- 2010 DF1
585Kiev Comet Station in the Ukraine, 1 in MPEC 2012-D60 -- 308635
704LINEAR in New Mexico, 1 in MPEC 2012-D60 -- 21277
J75La Sagra Obs. in Spain, 1 in MPEC 2012-D60 -- 2012 DA14
C94MASTER-II Obs. Tunka in Russia, 1 in MPEC 2012-D60 -- 101873
H01Magdalena Ridge Obs. in New Mexico, 1 in MPEC 2012-D61 -- 2010 DF1
5682David Tholen's team on Mauna Kea in Hawaii, 1 in MPEC 2012-D60 -- 2011 YU74
G96Mt. Lemmon Survey (MLS) in Arizona, 7 in MPECs 2012-D60 & 2012-D61 -- 2012 DY13, 2012 CA21, 2010 DF1, 53110, 39557, 310737, 137084
F51Pan-STARRS 1 (PS1) in Hawaii, 8 in MPEC 2012-D60 -- 2012 DH4, 2011 SO26, 2009 QE8, 2007 DK, 2002 CW46, 21277, 16912, 3102
691Spacewatch 0.9m telescope in Arizona, 5 in MPEC 2012-D60 -- 2012 DJ4, 2010 RJ42, 2009 CT5, 276049, 238063
291Spacewatch 1.8m telescope in Arizona, 10 in MPECs 2012-D60 & 2012-D61 -- 2012 DY13, 2012 DP8, 2012 DO8, 2012 DN, 2012 DJ4, 2012 CQ36, 2012 CK2, 2012 CA21, 2012 BJ86, 2010 DF1
J08Zonalunar Obs. in Spain, 3 in MPEC 2012-D60 -- 2012 BJ134, 2011 YV15, 2011 SL102
For a list of all participating observatories that have Web addresses, see A/CC's Observatory Links page.

Impact Risk Monitoring  on 25 February '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 DA14NEODyS23092020-20903092.98e-04-3.18-4.080NEODyS: "Based on 28 optical observations (of which 2 are rejected as outliers) from 2012-02-23.029 to 2012-02-25.056."
JPL Sentry15392020-20752203.9e-04-3.09-4.120JPL: "Analysis based on 26 observations spanning 2.0209 days (2012-Feb-23.03431 to 2012-Feb-25.055242)." Diameter approximately 0.047 km. from mean, weighted H=24.3.
2012 DY13NEODyS16312060-206015.16e-10-10.54-10.540NEODyS: "Based on 51 optical observations (of which 0 are rejected as outliers) from 2012-02-22.255 to 2012-02-25.194."
JPL Sentry1539R E M O V E DJPL: Risk listing removed at 0956 UTC.
2012 CA21JPL Sentry1930207311.5e-05-1.94-1.941JPL: "Analysis based on 79 observations spanning 12.991 days (2012-Feb-12.12022 to 2012-Feb-25.11154)." Diameter approximately 0.470 km. from mean, weighted H=19.3.
NEODyS15392073-207313.19e-06-2.61-2.610NEODyS: "Based on 79 optical observations (of which 3 are rejected as outliers) from 2012-02-12.121 to 2012-02-25.112."
2012 BJ86JPL Sentry1539211213.2e-07-5.04-5.040JPL: "Analysis based on 57 observations spanning 26.999 days (2012-Jan-29.10142 to 2012-Feb-25.10063)." Diameter approximately 0.160 km. from mean, weighted H=21.6.
NEODyS15392084-208425.3e-09-6.71-6.980NEODyS: "Based on 49 optical observations (of which 0 are rejected as outliers) from 2012-01-29.102 to 2012-02-25.101."

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 February '12

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

2359Grabbed MPEC 2012-D61 - 2010 DF1 - see above
2309Noted that NEODyS has posted 2012 DA14 as an impact risk - see above
1930Noted that JPL Sentry has updated its 2012 CA21 risk assessment - see above
1631Noted that NEODyS has updated its 2012 DY13 risk assessment - see above
1540Posted Traffic Report
1539Noted that JPL Sentry has updated its 2012 BJ86 risk assessment - see above
Noted that NEODyS has updated its 2012 BJ86 risk assessment - see above
Noted that NEODyS has updated its 2012 CA21 risk assessment - see above
Noted that JPL Sentry has updated its 2012 DA14 risk assessment - see above
Noted that JPL Sentry has removed 2012 DY13 as an impact risk - see above
Grabbed MPEC 2012-D60 - Daily Orbit Update - see above