Contents  on 29 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 29 February '12

Four objects reported inside ten LD

Four objects are reported moving within ten lunar distances (LD) of Earth today. Within Earth's Hill sphere, 2012 DS32 comes its closest to the Moon this time around, reaching 2.84 LD at 2336 UTC. Further out, risk-listed 2012 CS46 is calculated with great uncertainty to be moving from 5.6 to 7.1 LD*, new discovery 2012 DJ54 is outbound from 7.78 to 8.97 LD, and 2012 DN31 comes inward from 8.67 to 8.17 LD.

Approaching our neighborhood, 2012 DR32 and newly announced 2012 DH54 come inside ten LD tomorrow, and 2008 EJ85 arrives on March 4th.

This report was updated at 2114 UTC with new discoveries 2012 DJ54 (MPEC) and 2012 DH54 (MPEC) and, earlier, follow-up in today's DOU MPEC for 2012 DS32, 2012 DR32, 2012 DM32, and 2012 DA14, as well as distant 2009 DT10. This report was previously updated at 0109 and 1713 UTC.

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.

Radar Astrometry  on 29 February '12

Radar observation of three objects

The JPL Solar System Dynamics Group Radar Astrometry database has added or updated the following small-body radar observing work:

Data update noted at 0108 UTC when the database was dated 28 Feb.

Data update noted at 0207 UTC when the database was dated 28 Feb.

Data update noted at 2359 UTC when the database was dated 29 Feb.

NEOCP Activity  on 29 February '12

The MPC's NEO Confirmation Page has 28 listings

When last checked at 2300 UTC today, the Minor Planet Center's Near Earth Object discovery Confirmation Page (NEOCP) had 28 objects listed. Of these, eleven were "one nighters." The Tracking News counted a total of 44 listings on the NEOCP on this day.

New MPECs  on 29 February '12

Minor Planet Electronic Circulars

There were five MPECs posted this day from the International Astronomical Union's Minor Planet Center in Cambridge, Massachusetts.

MPEC 2012-D104 - "18:48 UT" - 2012 DJ54

MPEC 2012-D103 - "18:46 UT" - 2012 DH54

MPEC 2012-D102 - "18:44 UT" - 2012 DG54

MPEC 2012-D101 - "18:42 UT" - 2012 AN23

<< DOU on 29 Feb. '12 >>  MPEC 2012-D100 - "06:04 UT" - Daily Orbit Update

Observers  on 29 February '12

A total of 24 observers appeared in this day's MPECs.

CodeObserver / observatory
251Arecibo in Puerto Rico, 3 in radar -- 2006 CJ, 96590, 162421
H21Astronomical Research Obs. Westfield in Illinois, 19 in MPECs 2012-D100 & 2012-D102 -- 2012 DZ13, 2012 DW30, 2012 DS32, 2012 DR32, 2012 DQ32, 2012 DP32, 2012 DN14, 2012 DM32, 2012 DK31, 2012 DH4, 2012 DG54, 2012 DG31, 2012 DC28, 2012 DA14, 2012 CN46, 2012 CA21, 2012 AN23, 2008 CE119, 2005 TU50
J51Atlante Obs. in the Canary Islands, 1 in MPEC 2012-D100 -- 24475
300Bisei Spaceguard Center in Japan, 1 in MPEC 2012-D100 -- 2008 CE119
703Catalina Sky Survey in Arizona, 1 in MPEC 2012-D100 -- 2012 AN23
807|Robert Holmes in Illinois via Cerro Tololo Inter-American Obs. (CTIO) in Chile, 3 in MPECs 2012-D100 & 2012-D101 -- 2012 DQ8, 2012 BK11, 2012 AN23
F657Paul Roche in Wales via Faulkes Telescope North in Hawaii, 1 in MPEC 2012-D100 -- 2012 AN23
E10Faulkes Telescope South in New South Wales, 1 in MPEC 2012-D104 -- 2012 DJ54
253Goldstone DSS-14 70m antenna in southern California, 1 in radar -- 162421
H15ISON-NM Obs. in New Mexico, 1 in MPEC 2012-D100 -- 2012 DA14
704LINEAR in New Mexico, 3 in MPEC 2012-D100 -- 2011 SL102, 154555, 101873
950.Ovidiu Vaduvescu via La Palma in the Canary Islands, 3 in MPECs 2012-D100 & 2012-D102 -- 2012 DG54, 2008 CC119, 175706
J75La Sagra Obs. in Spain, 1 in MPEC 2012-D100 -- 2012 DA14
809>program code ">" via La Silla in Chile, 1 in MPEC 2012-D100 -- 142040
H01Magdalena Ridge Obs. (MRO) in New Mexico, 2 in MPECs 2012-D101 & 2012-D102 -- 2012 DG54, 2012 AN23
5682David Tholen's team on Mauna Kea in Hawaii, 2 in MPECs 2012-D103 & 2012-D104 -- 2012 DJ54, 2012 DH54
G96Mt. Lemmon Survey (MLS) in Arizona, 2 in MPECs 2012-D100 & 2012-D102 -- 2012 DG54, 2012 AN23
A24New Millennium Obs. in Italy, 21 in MPEC 2012-D100 -- 2012 DZ13, 2012 CD29, 2012 BJ134, 2011 YV15, 2011 SL102, 2004 QJ7, 85990, 275558, 237805, 21277, 163000, 162038, 153951, 142348, 141018, 137925, 101873, 6050, 4055, 3103, 1862
J43Oukaimeden Obs. in Morocco, 2 in MPEC 2012-D100 -- 7977, 1862
F51Pan-STARRS 1 (PS1) in Hawaii, 13 in MPECs 2012-D100, 2012-D103 & 2012-D104 -- 2012 DQ8, 2012 DJ54, 2012 DH54, 2012 DA33, 2004 QJ7, 1996 TE9, 38086, 267221, 16912, 141765, 136618, 5324, 3103
204Schiaparelli Obs. in Italy, 10 in MPEC 2012-D100 -- 2012 DY32, 2012 DV32, 2012 DL4, 2012 CA55, 2012 BK77, 2012 AN23, 2009 DT10, 2008 CE119, 2007 DK, 2003 FH1
E12Siding Spring Survey in New South Wales, 1 in MPEC 2012-D100 -- 1995 FX
291Spacewatch 1.8m telescope in Arizona, 8 in MPECs 2012-D100, 2012-D101 & 2012-D102 -- 2012 DN, 2012 DL31, 2012 DG54, 2012 DG4, 2012 CR36, 2012 AN23, 2010 ON101, 2010 DO
I93St. Pardon de Conques Obs. in France, 1 in MPEC 2012-D100 -- 2012 AN23
For a list of all participating observatories that have Web addresses, see A/CC's Observatory Links page.

Impact Risk Monitoring  on 29 February '12

Summary Risk Table for Risk Assessments Updated Today   (last checks: NEODyS at 2301 and JPL at 2300 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 DJ54JPL Sentry21192068-2108196.1e-05-6.32-6.560JPL: "Analysis based on 12 observations spanning 2.2489 days (2012-Feb-27.46779 to 2012-Feb-29.71672)." Diameter approximately 0.006 km. from mean, weighted H=28.7.
2012 DY43NEODyS16092048-207121.45e-09-7.37-7.410NEODyS: "Based on 6 optical observations (of which 0 are rejected as outliers) from 2012-02-27.490 to 2012-02-28.611."
2012 DA33NEODyS1609R E M O V E D-
2012 DA14JPL Sentry16092020-20571172.1e-04-3.31-4.090JPL: "Analysis based on 55 observations spanning 6.0511 days (2012-Feb-23.03431 to 2012-Feb-29.085416)." Diameter approximately 0.045 km. from mean, weighted H=24.4.
NEODyS16092020-20903633.43e-04-3.17-4.020NEODyS: "Based on 49 optical observations (of which 3 are rejected as outliers) from 2012-02-23.029 to 2012-02-27.632."
2012 CA21JPL Sentry1609207311.0e-06-3.14-3.140JPL: "Analysis based on 90 observations spanning 15.923 days (2012-Feb-12.12022 to 2012-Feb-28.04325)." Diameter approximately 0.440 km. from mean, weighted H=19.4.
NEODyS1609R 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 29 February '12

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

2359Noted Radar Astrometry database update - see above
2119Noted that JPL Sentry has posted 2012 DJ54 as an impact risk - see above
2114Updated Traffic Report
2001Grabbed MPEC 2012-D101 - 2012 AN23 - see above
Grabbed MPEC 2012-D102 - 2012 DG54 - see above
Grabbed MPEC 2012-D103 - 2012 DH54 - see above
Grabbed MPEC 2012-D104 - 2012 DJ54 - see above
1609Noted that JPL Sentry has updated its 2012 CA21 risk assessment - see above
Noted that NEODyS has removed 2012 CA21 as an impact risk - see above
Noted that JPL Sentry has updated its 2012 DA14 risk assessment - see above
Noted that NEODyS has updated its 2012 DA14 risk assessment - see above
Noted that NEODyS has removed 2012 DA33 as an impact risk - see above
Noted that NEODyS has posted 2012 DY43 as an impact risk - see above
Grabbed MPEC 2012-D100 - Daily Orbit Update - see above
0207Noted Radar Astrometry database update - see above
0108Noted Radar Astrometry database update - see above