Contents  on 18 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 18 April '12

Three objects reported inside ten LD

Three objects are reported inside ten lunar distances (LD) of our planet today. 2007 HV4 may be moving from 5.3 to 4.8 LD (with an Earth passage uncertainty of +/- 1.748 days), 2012 GW11 comes its closest to Earth this time around, reaching 4.94 LD at 1613 UTC, and radar target 2012 GP1 travels from 9.61 to 9.28 LD.

Approaching our neighborhood next, 2012 HE arrives inside ten LD tomorrow, 2012 HM on April 21st, newly discovered and risk-listed 2012 HQ is preliminarily calculated to dip inside on April 23rd, and 1992 JD comes inside on April 30th.

This report was generated at 1738 UTC with new discovery 2012 HQ (MPEC) and follow-up in today's DOU MPEC for inbound 2012 HM and 2012 GY11 and for departed 2012 DN31 and 2012 DA14.

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 18 April '12

The MPC's NEO Confirmation Page has 27 listings

When last checked at 2358 UTC today, the Minor Planet Center's Near Earth Object discovery Confirmation Page (NEOCP) had 27 objects listed. Of these, 21 were "one nighters." So far The Tracking News has counted a total of 49 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 18 April '12

Minor Planet Electronic Circulars

As of last check at 2358 UTC, there have been four MPECs posted today from the International Astronomical Union's Minor Planet Center in Cambridge, Massachusetts.

MPEC 2012-H21 - "18:36 UT" - 2009 OB3

MPEC 2012-H20 - "17:37 UT" - 2012 GB18

<< DOU on 18 Apr. '12 >>  MPEC 2012-H19 - "06:03 UT" - Daily Orbit Update

MPEC 2012-H18 - "00:29 UT" - 2012 HQ

Observers  on 18 April '12

Sixteen observers appear in today's MPECs.

CodeObserver / observatory
H21Astronomical Research Obs. Westfield in Illinois, 13 in MPECs 2012-H19 & 2012-H21 -- 2012 GD5, 2012 GB5, 2012 FZ44, 2012 FZ23, 2012 FR35, 2012 FH38, 2012 ET14, 2012 EA2, 2012 DN31, 2012 DK61, 2011 QD48, 2009 OB3, 2001 DF47
A74Bergen-Enkheim Obs. in Germany, 1 in MPEC 2012-H19 -- 2012 FJ
703Catalina Sky Survey (CSS) in Arizona, 11 in MPEC 2012-H19 -- 2012 GK, 2012 FL35, 2010 LR33, 2006 VY13, 2004 FF29, 2001 SZ269, 85275, 68348, 318450, 312942, 306595
807|Robert Holmes in Illinois via Cerro Tololo Inter-American Obs. (CTIO) in Chile, 5 in MPECs 2012-H18, 2012-H19 & 2012-H20 -- 2012 HQ, 2012 GY11, 2012 GB5, 2012 GB18, 2012 BJ11
I39Cruz del Sur Obs. in Argentina, 1 in MPEC 2012-H19 -- 2012 FG58
G48Doc Greiner Research Obs. Rancho Hildalgo in New Mexico, 1 in MPEC 2012-H19 -- 2012 HL
F65%Tim Lister in southern California via Faulkes Telescope North in Hawaii, 3 in MPECs 2012-H18, 2012-H19 & 2012-H20 -- 2012 HQ, 2012 HO, 2012 GB18
704LINEAR in New Mexico, 6 in MPEC 2012-H19 -- 2012 HM, 317643, 231937, 21088, 171819, 162186
H01Magdalena Ridge Obs. (MRO) in New Mexico, 3 in MPECs 2012-H19 & 2012-H20 -- 2012 GB18, 2012 DA14, 2001 SZ269
5682David Tholen's team on Mauna Kea in Hawaii, 1 in MPEC 2012-H19 -- 2012 GT5
G96Mt. Lemmon Survey in Arizona, 1 in MPEC 2012-H19 -- 2009 QE8
0892Oleksandr V. Shulga via Nikolaev Obs. in the Ukraine, 6 in MPEC 2012-H19 -- 2012 GD2, 2012 FY23, 2012 ES14, 2012 DO, 2011 QD48, 141018
F51Pan-STARRS 1 (PS1) in Hawaii, 2 in MPECs 2012-H18 & 2012-H20 -- 2012 HQ, 2012 GB18
691Spacewatch 0.9m telescope in Arizona, 8 in MPEC 2012-H19 -- 2012 FR62, 2012 DO, 2011 MB2, 2006 VY13, 2003 HB6, 2002 GK8, 2001 SZ269, 162063
291Spacewatch 1.8m telescope in Arizona, 10 in MPEC 2012-H19 -- 2012 GT5, 2012 GK, 2012 GG1, 2012 GC5, 2012 GA5, 2012 FS62, 2012 CL29, 2012 AT10, 2011 VQ5, 2010 SO16
A48Verona Obs. in Italy, 2 in MPEC 2012-H19 -- 2012 GC2, 2012 ES14
For a list of all participating observatories that have Web addresses, see A/CC's Observatory Links page.

Impact Risk Monitoring  on 18 April '12

Summary Risk Table for Risk Assessments Updated Today   (last checks: NEODyS and JPL at 2358 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 HQJPL Sentry0449210221.4e-09-8.88-9.070JPL: "Analysis based on 12 observations spanning 1.0375 days (2012-Apr-16.40683 to 2012-Apr-17.444353)." Diameter approximately 0.033 km. from mean, weighted H=25.0.
2012 GV17NEODyS16572025-2090803.08e-07-4.59-5.690NEODyS: "Based on 12 optical observations (of which 0 are rejected as outliers) from 2012-04-14.343 to 2012-04-17.229."
2012 DA14JPL Sentry16572020-21122245.3e-04-2.99-3.610JPL: "Analysis based on 175 observations spanning 54.323 days (2012-Feb-23.03431 to 2012-Apr-17.35691)." Diameter approximately 0.045 km. from mean, weighted H=24.4.
NEODyS16572020-20902484.51e-04-3.04-3.60NEODyS: "Based on 178 optical observations (of which 4 are rejected as outliers) from 2012-02-23.029 to 2012-04-17.358."
2010 AR85NEODyS1657R 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 18 April '12

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

1841Grabbed MPEC 2012-H21 - 2009 OB3 - see above
1745Grabbed MPEC 2012-H20 - 2012 GB18 - see above
1738Generated Traffic Report
1657Noted that NEODyS has removed 2010 AR85 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 posted 2012 GV17 as an impact risk - see above
Grabbed MPEC 2012-H19 - Daily Orbit Update - see above
0449Noted that JPL Sentry has posted 2012 HQ as an impact risk - see above
0037Grabbed MPEC 2012-H18 - 2012 HQ - see above