Contents  on 21 April '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 21 April '12

Six objects reported inside ten LD

Six asteroids are reported passing within ten lunar distances (LD) of Earth today. Inside Earth's Hill sphere, newly discovered and risk-listed 2012 HG2 is outbound from 2.67 to 3.39 LD. Further away, 2012 HN1 comes its closest to Earth this time around, reaching 5.21 LD at 1044 UTC, and radar target 2012 GP1 comes its closest on this passage -- 8.96 LD at 0607 UTC. Unobserved 2007 HV4 may be traveling from 6.0 to 7.4 LD (Earth passage uncertainty = +/- 1.748 days). 2012 HE is inbound from 7.61 to 7.00 LD and radar target 2012 HM comes inside ten LD, traveling from 10.74 to 9.32 LD.

Up next, newly announced 2012 HE2 arrives inside ten LD tomorrow, 2012 HQ on April 23rd, and 1992 JD on April 30th.

This report was updated at 1548 UTC with follow-up in today's DOU MPEC for 2012 HG2, 2012 HE2, 2012 HN1, 2012 HQ, 2012 HM, 2012 GP1, and distant 2007 HA, plus 2011 UX255 from last October. Today's first report at 0508 UTC noted two discoveries announced late yesterday: 2012 HG2 (MPEC) and 2012 HE2 (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. See also current sky chart and object details (alt-details), ephemerides, and today's timeline.

NEOCP Activity  on 21 April '12

The MPC's NEO Confirmation Page has 26 listings

When last checked at 2359 UTC today, the Minor Planet Center's Near Earth Object discovery Confirmation Page (NEOCP) had 26 objects listed. Of these, nineteen were "one nighters." So far The Tracking News has counted a total of 41 listings on the NEOCP today.

New MPECs  on 21 April '12

Minor Planet Electronic Circulars

As of last check at 2359 UTC, there have been eight MPECs posted today from the International Astronomical Union's Minor Planet Center in Cambridge, Massachusetts.


MPEC 2012-H43 - "17:45 UT" - 2001 QN142 = 2012 HP2


<< OOC on 21 Apr. '12 >> MPEC 2012-H42 - "16:07 UT" - Observations and Orbits of Comets


MPEC 2012-H41 - "11:19 UT" - 2012 HR2


MPEC 2012-H40 - "11:17 UT" - 2012 HQ2


MPEC 2012-H39 - "11:15 UT" - 2012 HP2


MPEC 2012-H38 - "11:13 UT" - 2012 HO2


MPEC 2012-H37 - "11:08 UT" - 2012 HN2


<< DOU on 21 Apr. '12 >>  MPEC 2012-H36 - "06:03 UT" - Daily Orbit Update

Observers  on 21 April '12

A total of 55 observers appear in today's MPECs.

CodeObserver / observatory
J24Altamira Obs. in the Canary Islands, 9 in MPEC 2012-H42 -- P/2012 F5, C/2012 CH17, C/2012 BJ98, C/2012 B3, C/2012 A2, C/2011 J2, C/2010 R1, 164P, 117P
H21Astronomical Research Obs. Westfield in Illinois, 1 in MPEC 2012-H37 -- 2012 HN2
467Auckland Obs. in New Zealand, 1 in MPEC 2012-H42 -- C/2011 L4
I47Auger Obs. in Argentina, 1 in MPEC 2012-H42 -- 96P
069Baldone Obs. in Latvia, 1 in MPEC 2012-H42 -- C/2009 P1
B88Bigmuskie Obs. in Italy, 1 in MPEC 2012-H36 -- 2011 QD48
C86Blanes Obs. in Spain, 4 in MPEC 2012-H42 -- C/2011 F1, C/2009 P1, 49P, 29P
I99Blanquita Obs. in Spain, 2 in MPEC 2012-H42 -- C/2011 F1, C/2009 P1
703Catalina Sky Survey (CSS) in Arizona, 11 in MPECs 2012-H36, 2012-H37 & 2012-H42 -- 2012 HN2, 2012 HM, 2012 FD1, C/2012 E3, C/2012 A2, 2008 UG7, 2008 GG2, 241370, 100926, 246P, 240P
807|Robert Holmes in Illinois via Cerro Tololo Inter-American Obs. (CTIO) in Chile, 2 in MPEC 2012-H36 -- 2012 HM1, 2012 GX11
G58Chabot Obs. in northern California, 1 in MPEC 2012-H36 -- 2011 UY114
J01Cielo Profundo Obs. in Spain, 7 in MPEC 2012-H42 -- C/2012 A2, C/2011 UF305, C/2011 F1, C/2010 R1, C/2006 S3, 49P, 29P
850Cordell-Lorenz Obs. in Tennessee, 2 in MPECs 2012-H36 & 2012-H42 -- 2012 ES14, 49P
821Cordoba Obs. Bosque Alegre Station in Argentina, 3 in MPECs 2012-H37, 2012-H38 & 2012-H40 -- 2012 HQ2, 2012 HO2, 2012 HN2
I39Cruz del Sur Obs. in Argentina, 1 in MPEC 2012-H36 -- 138852
G48Doc Greiner Research Obs. Rancho Hildalgo in New Mexico, 1 in MPEC 2012-H36 -- 6455
J04ESA Optical Ground Station in the Canary Islands, 1 in MPEC 2012-H36 -- 2011 UX255
C74El Teatrillo de Lyra Obs. in Spain, 1 in MPEC 2012-H42 -- C/2009 P1
E85Farm Cove Obs. in New Zealand, 2 in MPEC 2012-H42 -- C/2011 L4, C/2011 J2
E105Richard Miles in England via Faulkes Telescope South in New South Wales, 2 in MPEC 2012-H42 -- 67P, 17P
C73Galati Obs. in Romania, 2 in MPEC 2012-H42 -- C/2010 R1, 246P
372Geisei Obs. in Japan, 2 in MPEC 2012-H42 -- C/2012 A2, P/2011 FR143
203GiaGa Obs. in Italy, 3 in MPEC 2012-H36 -- 2012 HF2, 2012 HE2, 138852
651Grasslands Obs. in Arizona, 3 in MPECs 2012-H37, 2012-H38 & 2012-H40 -- 2012 HQ2, 2012 HO2, 2012 HN2
J95Great Shefford Obs. in England, 3 in MPECs 2012-H36, 2012-H38 & 2012-H39 -- 2012 HP2, 2012 HO2, 2012 HN1
511Haute Provence Obs. in Germany, 1 in MPEC 2012-H42 -- C/2012 CH17
C32Ka-Dar Obs. TAU Station in Russia, 7 in MPEC 2012-H42 -- C/2012 BJ98, P/2012 B1, C/2012 A2, P/2010 JC81, C/2010 FB87, C/2005 L3, 164P
585Kiev Comet Station in the Ukraine, 2 in MPECs 2012-H36 & 2012-H42 -- C/2009 P1, 3352
D95Kurihara Obs. in Japan, 5 in MPEC 2012-H42 -- C/2011 J2, C/2011 F1, 246P, 117P, 29P
704LINEAR in New Mexico, 6 in MPECs 2012-H36 & 2012-H42 -- 2012 HL, C/2012 BJ98, C/2011 L4, C/2011 J2, 189008, 9400
H01Magdalena Ridge Obs. (MRO) in New Mexico, 2 in MPECs 2012-H38 & 2012-H43 -- 2012 HP2, 2012 HO2
C10Maisoncelles Obs. in France, 4 in MPEC 2012-H42 -- P/2012 F5, 246P, 49P, 29P
568}program code "}" (33) on Mauna Kea in Hawaii, 1 in MPEC 2012-H36 -- 2012 FC71
213Montcabre Obs. in Spain, 3 in MPEC 2012-H42 -- C/2011 F1, C/2009 P1, 29P
A99Monte Baldo Obs. in Italy, 1 in MPEC 2012-H36 -- 138852
900Moriyama Obs. in Japan, 14 in MPEC 2012-H42 -- C/2012 CH17, C/2012 B3, P/2012 B1, C/2012 A2, C/2011 UF305, C/2011 J2, C/2011 F1, C/2010 R1, P/2010 JC81, C/2009 P1, C/2006 S3, 246P, 49P, 29P
474Mt. John Obs. in New Zealand, 3 in MPECs 2012-H37, 2012-H38 & 2012-H40 -- 2012 HQ2, 2012 HO2, 2012 HN2
G96Mt. Lemmon Survey (MLS) in Arizona, 14 in MPECs 2012-H36, 2012-H37, 2012-H38, 2012-H39, 2012-H40, 2012-H41 & 2012-H42 -- 2012 HR2, 2012 HQ2, 2012 HP2, 2012 HO2, 2012 HN2, 2012 GV17, C/2012 BJ98, C/2011 J2, 2007 UB6, 86667, 154229, 136618, 3102, 162P
E07Murrumbateman Obs. in New South Wales, 3 in MPEC 2012-H42 -- P/2012 F5, 123P, 29P
0892Oleksandr V. Shulga via Nikolaev Obs. in the Ukraine, 3 in MPEC 2012-H42 -- C/2012 A2, C/2011 UF305, 246P
0893program code 3 via Nikolaev Obs. in the Ukraine, 3 in MPEC 2012-H36 -- 209924, 154302, 136923
C23Olmen Obs. in Belgium, 12 in MPEC 2012-H42 -- C/2012 BJ98, C/2012 A2, C/2011 UF305, C/2010 S1, C/2010 R1, P/2010 JC81, C/2009 P1, C/2006 S3, 246P, 78P, 49P, 29P
F51Pan-STARRS 1 (PS1) in Hawaii, 11 in MPECs 2012-H36, 2012-H37 & 2012-H42 -- 2012 HN2, P/2012 F2, 2012 DO, C/2010 R1, 2009 HU58, 2008 GG2, 189062, 152889, 10150, 103P, 29P
H23Pear Tree Obs. in Florida, 4 in MPECs 2012-H36 & 2012-H42 -- 2012 DO, C/2012 CH17, C/2011 F1, 49P
H45Petit Jean Mtn. South Obs. (PJMSO) in Arkansas, 6 in MPEC 2012-H42 -- C/2012 CH17, C/2012 A2, C/2011 F1, C/2009 P1, 49P, 29P
D90`Kevin Hills in England via RAS Obs. Moorook in South Australia, 1 in MPEC 2012-H42 -- C/2009 F4
619Sabadell Obs. in Spain, 1 in MPEC 2012-H36 -- 1866
H36Sandlot Obs. in Kansas, 7 in MPECs 2012-H36, 2012-H38, 2012-H40 & 2012-H41 -- 2012 HR2, 2012 HQ2, 2012 HO2, 2012 HO1, 2012 GS5, 2012 FC71, 2007 HA
204Schiaparelli Obs. in Italy, 1 in MPEC 2012-H36 -- 2012 HE2
510Siegen Obs. in Germany, 1 in MPEC 2012-H36 -- 2012 HG2
691Spacewatch 0.9m telescope in Arizona, 8 in MPECs 2012-H36 & 2012-H42 -- 2012 DO, P/2011 C2, 2010 LJ14, 2008 HW1, 318450, 257P, 228P, 31P
291Spacewatch 1.8m telescope in Arizona, 19 in MPECs 2012-H36 & 2012-H39 -- 2012 HQ, 2012 HP2, 2012 GX11, 2012 GV17, 2012 GV11, 2012 GT5, 2012 GS5, 2012 GP1, 2012 GK, 2012 GG1, 2012 GD5, 2012 GC5, 2012 GB5, 2012 GA5, 2012 FU62, 2012 FQ1, 2012 FK35, 2012 FC71, 2010 LR33
A71Stixendorf Obs. in Austria, 4 in MPEC 2012-H42 -- C/2011 L4, C/2010 R1, C/2006 S3, 78P
H47Vicksburg Obs. in Mississippi, 7 in MPEC 2012-H42 -- C/2012 CH17, C/2011 J2, C/2010 R1, C/2006 S3, 152P, 49P, 29P
G56Walnut Creek Obs. in northern California, 4 in MPEC 2012-H36 -- 2012 HM, 2012 HK, 2012 GC2, 2012 ES14
367Yatsuka Obs. in Japan, 9 in MPEC 2012-H42 -- C/2011 UF305, C/2011 L4, C/2011 F1, C/2011 A3, C/2010 S1, C/2009 P1, 246P, 78P, 49P
For a list of all participating observatories that have Web addresses, see A/CC's Observatory Links page.

Impact Risk Monitoring  on 21 April '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.
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 HG2JPL Sentry15442048-2059241.9e-04-4.78-5.530JPL #2 for the day: "Analysis based on 41 observations spanning .61046 days (2012-Apr-20.37147 to 2012-Apr-20.981927)." Diameter approximately 0.014 km. from mean, weighted H=26.9.
2012 GV17JPL Sentry15442031-2110611.9e-06-3.92-4.510JPL: "Analysis based on 17 observations spanning 5.9174 days (2012-Apr-14.34248 to 2012-Apr-20.25992)." Diameter approximately 0.200 km. from mean, weighted H=21.2.
NEODyS15442031-2089348.38e-07-4.13-4.580NEODyS: "Based on 17 optical observations (of which 0 are rejected as outliers) from 2012-04-14.343 to 2012-04-20.261."
2012 DA14NEODyS15442020-20902052.75e-04-3.29-3.80NEODyS: "Based on 184 optical observations (of which 4 are rejected as outliers) from 2012-02-23.029 to 2012-04-19.402."

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 21 April '12

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

1818Grabbed MPEC 2012-H43 - 2001 QN142 = 2012 HP2 - see above
1623Grabbed MPEC 2012-H42 - Observations and Orbits of Comets - see above
1548Updated Traffic Report
1544Noted that NEODyS has updated its 2012 DA14 risk assessment - see above
Noted that JPL Sentry has updated its 2012 GV17 risk assessment - see above
Noted that NEODyS has updated its 2012 GV17 risk assessment - see above
Noted that JPL Sentry has updated its 2012 HG2 risk assessment - see above
Grabbed MPEC 2012-H36 - Daily Orbit Update - see above
Grabbed MPEC 2012-H37 - 2012 HN2 - see above
Grabbed MPEC 2012-H38 - 2012 HO2 - see above
Grabbed MPEC 2012-H39 - 2012 HP2 - see above
Grabbed MPEC 2012-H40 - 2012 HQ2 - see above
Grabbed MPEC 2012-H41 - 2012 HR2 - see above
0507Noted that JPL Sentry has posted 2012 HG2 as an impact risk - see above