Contents  on 20 September '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 20 September '12

Two objects reported inside ten LD

Two asteroids are reported moving within ten lunar distances (LD) of Earth today. 2012 SW2 exits Earth's Hill sphere, going from 2.34 to 5.41 LD and 2012 SZ2 is outbound from 8.21 to 8.66 LD.

On approach next, 2012 RK15 arrives inside ten LD on September 22nd and 2010 JK1 on November 22nd.

This report was updated at 2117 UTC with new discovery 2012 SU9 (MPEC), which has already departed from within ten LD. The traffic report was first generated at 1326 UTC with follow-up in today's DOU MPEC for 2012 SW2, 2012 RR16, 2012 RM15, 2012 RK15, and 2012 QG42.

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 20 September '12

The MPC's NEO Confirmation Page has 17 listings

When last checked at 2359 UTC today, the Minor Planet Center's Near Earth Object discovery Confirmation Page (NEOCP) had seventeen objects listed. Of these, five were "one nighters." So far The Tracking News has counted a total of 24 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 20 September '12

Minor Planet Electronic Circulars

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

MPEC 2012-S41 - "17:48 UT" - 2012 SV9

MPEC 2012-S40 - "17:46 UT" - 2012 SU9

MPEC 2012-S39 - "17:41 UT" - 2012 ST9

<< DOU on 20 Sept. '12 >>  MPEC 2012-S38 - "06:02 UT" - Daily Orbit Update

Observers  on 20 September '12

Nineteen observers appear in today's MPECs.

CodeObserver / observatory
H21Astronomical Research Obs. Westfield in Illinois, 16 in MPECs 2012-S38, 2012-S39, 2012-S40 & 2012-S41 -- 2012 SY2, 2012 SV9, 2012 SU9, 2012 ST9, 2012 SA3, 2012 RX16, 2012 RV16, 2012 RR16, 2012 RK15, 2012 RJ15, 2012 RH15, 2012 QF49, 2012 QE50, 2012 HN8, 2009 TB8, 303262
703Catalina Sky Survey (CSS) in Arizona, 8 in MPEC 2012-S38 -- 2012 RM15, 2012 QX17, 2012 QF42, 2012 MN2, 2012 JS11, 2000 SD8, 85818, 6047
448Desert Moon Obs. in New Mexico, 5 in MPEC 2012-S38 -- 2012 RH3, 2002 TY68, 52381, 318411, 276397
J95Great Shefford Obs. in England, 2 in MPECs 2012-S38 & 2012-S39 -- 2012 SW2, 2012 ST9
H15ISON-NM Obs. in New Mexico, 1 in MPEC 2012-S38 -- 333311
682Kanab Obs. in Utah, 1 in MPEC 2012-S39 -- 2012 ST9
704LINEAR in New Mexico, 8 in MPEC 2012-S38 -- 2012 SK8, 2012 LE11, 334412, 326732, 277127, 11054, 5646, 4179
H01Magdalena Ridge Obs. (MRO) in New Mexico, 3 in MPECs 2012-S39, 2012-S40 & 2012-S41 -- 2012 SV9, 2012 SU9, 2012 ST9
711McDonald Obs. in Texas, 3 in MPECs 2012-S38 & 2012-S39 -- 2012 ST9, 2012 SM8, 2012 SK8
474Mt. John Obs. in New Zealand, 7 in MPECs 2012-S38 & 2012-S39 -- 2012 ST9, 2012 RN6, 2012 RL15, 2012 RK15, 2012 RB3, 2012 HZ33, 2008 HA38
G96Mt. Lemmon Survey (MLS) in Arizona, 8 in MPECs 2012-S38, 2012-S39, 2012-S40 & 2012-S41 -- 2012 SV9, 2012 SU9, 2012 ST9, 2012 QP17, 2009 TG10, 333311, 162635, 6063
C39Nijmegen Obs., 6 in MPEC 2012-S38 -- 2007 RT19, 2002 RC118, 333889, 333358, 330825, 329520
583Odessa-Mayaki Obs. in the Ukraine, 2 in MPEC 2012-S38 -- 2012 QG42, 4179
H45Petit Jean Mtn. South Obs. (PJMSO) in Arkansas, 17 in MPEC 2012-S38 -- 2012 RM2, 2012 QY14, 2012 QX17, 2012 QQ50, 2012 QP17, 2012 QO10, 2012 QJ2, 2012 QE50, 2012 QB17, 2012 PS17, 2012 BZ76, 2008 CZ21, 2007 RT19, 2002 RC118, 2000 RH60, 1994 EK, 214869
H06|Hidetaka Sato in Japan via RAS Obs. Mayhill in New Mexico, 1 in MPEC 2012-S38 -- 2009 HC82
H36Sandlot Obs. in Kansas, 2 in MPECs 2012-S38 & 2012-S39 -- 2012 ST9, 2012 SK8
204Schiaparelli Obs. in Italy, 3 in MPECs 2012-S38 & 2012-S39 -- 2012 ST9, 2012 RX16, 2012 RV16
291Spacewatch 1.8m telescope in Arizona, 4 in MPEC 2012-S38 -- 2012 RJ15, 2012 QG8, 2012 HN40, 2010 OD101
C36Starry Wanderer Obs. in Belarus, 1 in MPEC 2012-S38 -- 2012 QE50
For a list of all participating observatories that have Web addresses, see A/CC's Observatory Links page.

Impact Risk Monitoring  on 20 September '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 SU9JPL Sentry20052091-211151.4e-06-7.22-7.350JPL: "Analysis based on 28 observations spanning 1.1904 days (2012-Sep-19.22484 to 2012-Sep-20.41527)." Diameter approximately 0.012 km. from mean, weighted H=27.2.
2012 SA3JPL Sentry1325R E M O V E DJPL: Risk listing removed at 0852 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 20 September '12

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

2117Updated Traffic Report
2005Noted that JPL Sentry has posted 2012 SU9 as an impact risk - see above
1901Grabbed MPEC 2012-S39 - 2012 ST9 - see above
Grabbed MPEC 2012-S40 - 2012 SU9 - see above
Grabbed MPEC 2012-S41 - 2012 SV9 - see above
1325Noted that JPL Sentry has removed 2012 SA3 as an impact risk - see above
Grabbed MPEC 2012-S38 - Daily Orbit Update - see above