Contents  on 23 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 23 April '12

Nine objects reported inside ten LD

There are nine visitors reported traveling within ten lunar distances (LD) of our planet today. Risk-listed 2012 HG2 is outbound from 4.13 to 4.89 LD, 2012 HN1 from 5.52 to 6.03 LD, 2012 HE from 6.96 to 7.50 LD, and radar target 2012 GP1 from 9.15 to 9.41 LD. Unreported 2007 HV4 may be exiting ten LD, moving from 9.1 to 10.8 LD (Earth passage uncertainty = +/- 1.748 days). Radar target 2012 HM is inbound from 7.90 to 6.50 LD and 2012 HE2 from 9.50 to 8.93 LD, and 2012 HQ enters ten LD, moving from 11.41 to 9.89 LD, as does newly announced 2012 HP13, passing from 12.52 to 9.67 LD.

Coming our way next, 1992 JD is calculated with some uncertainty to arrive inside ten LD on April 30th.

This report was updated at 2356 UTC with two new discoveries: approaching 2012 HP13 (MPEC) and departed intruder 2012 HM13 (MPEC) and, earlier, follow-up in today's DOU MPEC for 2012 HG2, 2012 HM, 2012 GP1, and distant 2007 HA. Today's first traffic report was posted at 1649 UTC.

Notes: Ten times the distance to the Moon (ten LD) has no astronomical significance but is a useful reporting boundary. 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 23 April '12

The MPC's NEO Confirmation Page has 19 listings

When last checked at 2358 UTC today, the Minor Planet Center's Near Earth Object discovery Confirmation Page (NEOCP) had nineteen objects listed. Of these, nine were "one nighters." So far The Tracking News has counted a total of 26 listings on the NEOCP today.

New MPECs  on 23 April '12

Minor Planet Electronic Circulars

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

MPEC 2012-H60 - "22:12 UT" - 2012 HP13

MPEC 2012-H59 - "22:10 UT" - 2012 HO13

MPEC 2012-H58 - "22:09 UT" - 2012 HN13

MPEC 2012-H57 - "22:03 UT" - 2012 HM13

MPEC 2012-H56 - "16:35 UT" - 2003 WH166

<< DOU on 23 Apr. '12 >>  MPEC 2012-H55 - "06:03 UT" - Daily Orbit Update

Observers  on 23 April '12

A total of 22 observers appear in today's MPECs.

CodeObserver / observatory
H21Astronomical Research Obs. Westfield in Illinois, 3 in MPECs 2012-H56, 2012-H59 & 2012-H60 -- 2012 HP13, 2012 HO13, 2003 WH166
300Bisei Spaceguard Center in Japan, 1 in MPEC 2012-H60 -- 2012 HP13
703Catalina Sky Survey (CSS) in Arizona, 10 in MPECs 2012-H55 & 2012-H60 -- 2012 HP13, 2012 HM, 2012 FY23, 2012 FL35, 2012 FJ, 2008 GG2, 89959, 36183, 154555, 141525
807|Robert Holmes in Illinois via Cerro Tololo Inter-American Obs. (CTIO) in Chile, 5 in MPEC 2012-H55 -- 2012 HR2, 2012 HQ2, 2012 HO2, 2012 HJ1, 2012 GA12
448Desert Moon Obs. in New Mexico, 3 in MPEC 2012-H55 -- 2012 FY23, 1999 VP6, 68267
G48Doc Greiner Research Obs. Rancho Hildalgo (DGRO-RH) in New Mexico, 2 in MPEC 2012-H55 -- 2012 HG8, 6455
A17Guidestar Obs. in Germany, 1 in MPEC 2012-H60 -- 2012 HP13
704LINEAR in New Mexico, 6 in MPECs 2012-H55 & 2012-H56 -- 2012 HK8, 2012 HG8, 2012 HG2, 2003 WH166, 1998 HE3, 302830
H01Magdalena Ridge Obs. (MRO) in New Mexico, 2 in MPECs 2012-H55 & 2012-H58 -- 2012 HN13, 101955
B67Mirasteilas Obs. in Switzerland, 1 in MPEC 2012-H55 -- 2011 SL102
118Modra Obs. in Slovakia, 1 in MPEC 2012-H60 -- 2012 HP13
474Mt. John Obs. in New Zealand, 5 in MPECs 2012-H55 & 2012-H57 -- 2012 HM13, 2012 HF2, 2009 KV2, 2007 HA, 152754
G96Mt. Lemmon Survey (MLS) in Arizona, 5 in MPECs 2012-H55, 2012-H56 & 2012-H57 -- 2012 HM13, 2012 HM1, 2003 WH166, 1998 HJ3, 85839
C47Nonndorf Obs. in Austria, 2 in MPEC 2012-H55 -- 2012 HM, 2012 FY23
F51Pan-STARRS 1 (PS1) in Hawaii, 4 in MPECs 2012-H55, 2012-H57 & 2012-H58 -- 2012 HN13, 2012 HM13, 163000, 162038
H45Petit Jean Mtn. South Obs. (PJMSO) in Arkansas, 9 in MPEC 2012-H55 -- 2012 HM, 2012 HJ1, 2012 HG2, 2012 FY23, 2012 AA11, 2011 YV15, 2011 QD48, 2006 VY13, 1994 NK
104San Marcello Pistoiese Obs. in Italy, 1 in MPEC 2012-H55 -- 2012 HM
H36Sandlot Obs. in Kansas, 4 in MPECs 2012-H55, 2012-H58, 2012-H59 & 2012-H60 -- 2012 HP13, 2012 HO13, 2012 HN13, 101955
204Schiaparelli Obs. in Italy, 1 in MPEC 2012-H55 -- 2012 GC2
J84South Obs. in England, 1 in MPEC 2012-H55 -- 2012 HG2
691Spacewatch 0.9m telescope in Arizona, 1 in MPEC 2012-H55 -- 2001 SZ269
291Spacewatch 1.8m telescope in Arizona, 6 in MPECs 2012-H55, 2012-H57, 2012-H58 & 2012-H59 -- 2012 HO13, 2012 HN13, 2012 HM13, 2012 GV11, 2012 GP1, 2010 CG18
For a list of all participating observatories that have Web addresses, see A/CC's Observatory Links page.

Impact Risk Monitoring  on 23 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.





Notes for Today's Latest Risk Assessments
2012 HG8JPL Sentry16482022-2066241.6e-06-2.66-2.940JPL: "Analysis based on 84 observations spanning 2.1091 days (2012-Apr-20.25484 to 2012-Apr-22.36394)." Diameter approximately 0.376 km. from mean, weighted H=19.8.
NEODyS16482023-2059188.57e-07-2.79-3.020NEODyS: "Based on 84 optical observations (of which 0 are rejected as outliers) from 2012-04-20.256 to 2012-04-22.365."
2012 HG2JPL Sentry16482053-206091.1e-04-5.07-5.670JPL: "Analysis based on 88 observations spanning 2.0152 days (2012-Apr-20.37147 to 2012-Apr-22.38666)." Diameter approximately 0.014 km. from mean, weighted H=27.0.
NEODyS16482053-20902799.61e-04-4.21-5.130NEODyS: "Based on 88 optical observations (of which 9 are rejected as outliers) from 2012-04-20.372 to 2012-04-22.387."

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 23 April '12

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

2356Updated Traffic Report
2304Grabbed MPEC 2012-H58 - 2012 HN13 - see above
Grabbed MPEC 2012-H59 - 2012 HO13 - see above
Grabbed MPEC 2012-H60 - 2012 HP13 - see above
2207Grabbed MPEC 2012-H57 - 2012 HM13 - see above
1648Noted that JPL Sentry has updated its 2012 HG2 risk assessment - see above
Noted that NEODyS 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 posted 2012 HG8 as an impact risk - see above
Grabbed MPEC 2012-H55 - Daily Orbit Update - see above
Grabbed MPEC 2012-H56 - 2003 WH166 - see above