Contents  on 30 April '12

Note: These A/CC news pages will update infrequently through Thursday, May 3rd, possibly less than daily.

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 30 April '12

Five objects reported inside ten LD

There are five objects reported traveling within ten lunar distances (LD) of our planet today. Inside Earth's Hill sphere, risk-listed 2012 HE31 comes its closest to Earth this time around, reaching 2.71 LD at 0818 UTC, and radar target 2012 HM exits the sphere, moving from 2.69 to 3.97 LD.

Further away, risk-listed 2012 HP13 leaves ten LD, passing from 8.17 to 11.00 LD, as does risk-listed 2012 HG2, traveling from 9.57 to 10.37 LD, while 1992 JD comes within, flying from 10.1 to 9.7 LD*.

Up next, 2010 KK37 arrives inside ten LD on May 15th.

This report was generated at 2327 UTC with follow-up in today's DOU MPEC for 2012 HG2 and 2012 HM plus the recovery of distant 2011 LT17 (MPEC).


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. Object distances are interpreted by A/CC from JPL Horizons data. "LD*" indicates some passage uncertainty. See also current sky chart and object details (alt-details), ephemerides, and today's timeline.

Radar Astrometry  on 30 April '12

Radar observation of one object

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


Data update noted at 2008 UTC when the database was dated 30 April

NEOCP Activity  on 30 April '12

The MPC's NEO Confirmation Page has 7 listings

When last checked at 2344 UTC today, the Minor Planet Center's Near Earth Object discovery Confirmation Page (NEOCP) had seven objects listed. Of these, two were "one nighters." So far The Tracking News has counted a total of nine listings on the NEOCP today.

New MPECs  on 30 April '12

Minor Planet Electronic Circulars

As of last check at 2344 UTC, there have been five MPECs posted today from the International Astronomical Union's Minor Planet Center in Cambridge, Massachusetts.


MPEC 2012-H95 - "20:49 UT" - 2012 HY33


MPEC 2012-H94 - "19:55 UT" - Comet P/2012 H1 (Panstarrs)


MPEC 2012-H93 - "12:06 UT" - 2006 WJ3


MPEC 2012-H92 - "12:03 UT" - 2011 LT17


<< DOU on 30 Apr. '12 >>  MPEC 2012-H91 - "06:04 UT" - Daily Orbit Update

Observers  on 30 April '12

Eighteen observers appear in today's MPECs.

CodeObserver / observatory
251Arecibo in Puerto Rico, 1 in radar -- 2003 WH166
160Castelmartini Obs. in Italy, 11 in MPEC 2012-H91 -- 2010 KX7, 2006 VY13, 2004 FF29, 2003 HB6, 96536, 86667, 85628, 66391, 66272, 141531, 112985
703Catalina Sky Survey (CSS) in Arizona, 6 in MPEC 2012-H91 -- 2004 QJ7, 2003 WH166, 1994 NK, 86667, 234341, 5587
106Crni Vrh Obs. in Slovenia, 1 in MPEC 2012-H91 -- 2012 HL
448Desert Moon Obs. in New Mexico, 7 in MPEC 2012-H91 -- 2012 HN2, 2012 FR62, 2012 FE58, 66272, 212359, 138847, 9400
E100Tim Lister in southern California via Faulkes Telescope South in New South Wales, 1 in MPEC 2012-H95 -- 2012 HY33
704LINEAR in New Mexico, 1 in MPEC 2012-H91 -- 2012 FE58
C01Lohrmann Obs. in Germany, 5 in MPEC 2012-H91 -- 2003 WH166, 1994 NK, 86667, 186823, 141018
C41MASTER-II Obs. Kislovodsk in Russia, 1 in MPEC 2012-H91 -- 6455
5682David Tholen's team on Mauna Kea in Hawaii, 1 in MPEC 2012-H93 -- 2006 WJ3
G96Mt. Lemmon Survey (MLS) in Arizona, 3 in MPECs 2012-H91 & 2012-H94 -- 2012 HK31, P/2012 H1, 16657
A24New Millennium Obs. in Italy, 1 in MPEC 2012-H91 -- 2012 FY23
F51Pan-STARRS 1 (PS1) in Hawaii, 2 in MPECs 2012-H94 & 2012-H95 -- 2012 HY33, P/2012 H1
D90`Kevin Hills in England via RAS Obs. Moorook in South Australia, 1 in MPEC 2012-H91 -- 2012 HG31
691Spacewatch 0.9m telescope in Arizona, 6 in MPECs 2012-H91 & 2012-H94 -- 2012 HG2, P/2012 H1, 2012 DX32, 65909, 189008, 154715
291Spacewatch 1.8m telescope in Arizona, 10 in MPECs 2012-H91, 2012-H92, 2012-H94 & 2012-H95 -- 2012 HY33, 2012 HO13, 2012 HH20, 2012 HG8, 2012 HB25, P/2012 H1, 2012 GV17, 2011 LT17, 2010 SO16, 2010 LR33
A98Taurus-1 Obs. in Belarus, 1 in MPEC 2012-H91 -- 2012 FY23
954Teide Obs. in the Canary Islands, 1 in MPEC 2012-H91 -- 2012 HM
For a list of all participating observatories that have Web addresses, see A/CC's Observatory Links page.

Impact Risk Monitoring  on 30 April '12

Summary Risk Table for Risk Assessments Updated Today   (last checks: NEODyS and JPL at 2344 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.
0000NNN000

Object

Risk
Monitor
When
Noted
UTC
0000T0000
Year
Range

VI
#
000NN00
Prob
Cum
T0000
PS
Cum
T0000
PS
Max

T
S


Notes for Today's Latest Risk Assessments
2012 HJ31NEODyS17392086-208616.84e-10-9.14-9.140NEODyS: "Based on 9 optical observations (of which 0 are rejected as outliers) from 2012-04-28.285 to 2012-04-29.293."
2012 HE31NEODyS17392083-208317.35e-08-7.67-7.670NEODyS: "Based on 18 optical observations (of which 0 are rejected as outliers) from 2012-04-27.199 to 2012-04-29.480."
2012 HB25NEODyS17392016-2090112.87e-05-3.91-4.060NEODyS: "Based on 19 optical observations (of which 0 are rejected as outliers) from 2012-04-24.354 to 2012-04-30.203."
JPL Sentry17382016-2090132.5e-05-3.92-4.230JPL: "Analysis based on 19 observations spanning 5.8496 days (2012-Apr-24.35308 to 2012-Apr-30.20269)." Diameter approximately 0.037 km. from mean, weighted H=24.8.
2012 HG8JPL Sentry2310203016.7e-08-3.92-3.920JPL #2 for the day: "Analysis based on 142 observations spanning 9.9119 days (2012-Apr-20.25484 to 2012-Apr-30.16675)." Diameter approximately 0.370 km. from mean, weighted H=19.8.
NEODyS1738R E M O V E D-
2012 HG2JPL Sentry23102053-205671.4e-05-5.96-6.080JPL #2 for the day: "Analysis based on 129 observations spanning 9.0663 days (2012-Apr-20.37147 to 2012-Apr-29.43775)." Diameter approximately 0.014 km. from mean, weighted H=27.0.
NEODyS17392053-20912661.05e-03-4.19-4.940NEODyS: "Based on 129 optical observations (of which 9 are rejected as outliers) from 2012-04-20.372 to 2012-04-29.439."
2012 ECJPL Sentry1738211113.5e-07-6.22-6.220JPL: "Analysis based on 106 observations spanning 42.099 days (2012-Mar-01.3419 to 2012-Apr-12.44099)." Diameter approximately 0.071 km. from mean, weighted H=23.4.
2012 DA14JPL Sentry23102020-2082733.1e-04-3.24-3.820JPL: "Analysis based on 185 observations spanning 62.448 days (2012-Feb-23.03431 to 2012-Apr-25.482804)." Diameter approximately 0.045 km. from mean, weighted H=24.4.
2011 LT17JPL Sentry1738R E M O V E DJPL: Risk listing removed at 1355 UTC.

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 30 April '12

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

2327Generated Traffic Report
2310Noted that JPL Sentry has updated its 2012 DA14 risk assessment - see above
Noted that JPL Sentry has updated its 2012 HG2 risk assessment - see above
Noted that JPL Sentry has updated its 2012 HG8 risk assessment - see above
Grabbed MPEC 2012-H94 - Comet P/2012 H1 (Panstarrs) - see above
Grabbed MPEC 2012-H95 - 2012 HY33 - see above
2008Noted Radar Astrometry database update - see above
1807Grabbed MPEC 2012-H91 - Daily Orbit Update - see above
Grabbed MPEC 2012-H92 - 2011 LT17 - see above
Grabbed MPEC 2012-H93 - 2006 WJ3 - see above
1739Noted that NEODyS has updated its 2012 HB25 risk assessment - see above
Noted that NEODyS has updated its 2012 HG2 risk assessment - see above
1738Noted that JPL Sentry has removed 2011 LT17 as an impact risk - see above
Noted that JPL Sentry has reposted 2012 EC as an impact risk - see above
Noted that JPL Sentry has updated its 2012 HB25 risk assessment - see above
Noted that NEODyS has posted 2012 HE31 as an impact risk - see above
Noted that JPL Sentry has updated its 2012 HG2 risk assessment - see above
Noted that JPL Sentry has updated its 2012 HG8 risk assessment - see above
Noted that NEODyS has removed 2012 HG8 as an impact risk - see above
Noted that NEODyS has posted 2012 HJ31 as an impact risk - see above