Contents  on 27 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 27 September '12

Two objects reported inside ten LD

Two objects are reported traveling inside ten lunar distances (LD) of our planet today. Risk-listed 2012 SY49 enters Earth's Hill sphere, sliding from 4.54 to 2.62 LD, and 2012 SL50 is also inside the sphere, coming its closest to Earth on this passage -- 2.84 LD at 0744 UTC.

Coming our way next, 2010 JK1 arrives inside ten LD on November 22nd.

This report was generated at 1511 UTC with follow-up in today's DOU MPEC for 2012 SL50 and 2012 SY49.

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 27 September '12

The MPC's NEO Confirmation Page has 20 listings

When last checked at 2358 UTC today, the Minor Planet Center's Near Earth Object discovery Confirmation Page (NEOCP) had 20 objects listed. Of these, nine were "one nighters." So far The Tracking News has counted a total of 29 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 27 September '12

Minor Planet Electronic Circulars

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

MPEC 2012-S79 - "19:41 UT" - Comet P/2012 S2 (La Sagra)

<< DOU on 27 Sept. '12 >>  MPEC 2012-S78 - "06:03 UT" - Daily Orbit Update

Observers  on 27 September '12

A total of 20 observers appear in today's MPECs.

CodeObserver / observatory
H21Astronomical Research Obs. Westfield in Illinois, 1 in MPEC 2012-S79 -- P/2012 S2
I47Auger Obs. in Argentina, 1 in MPEC 2012-S79 -- P/2012 S2
300Bisei Spaceguard Center in Japan, 3 in MPECs 2012-S78 & 2012-S79 -- 2012 SL50, P/2012 S2, 2012 QE50
703Catalina Sky Survey (CSS) in Arizona, 4 in MPEC 2012-S78 -- 303262, 162911, 10302, 7888
470Ceccano Obs. in Italy, 1 in MPEC 2012-S79 -- P/2012 S2
807|Robert Holmes in Illinois via Cerro Tololo Inter-American Obs. (CTIO) in Chile, 9 in MPEC 2012-S78 -- 2012 SZ49, 2012 SY49, 2012 SK8, 2012 SJ32, 2012 SH32, 2012 SD22, 2012 QP10, 2009 DV42, 66146
850Cordell-Lorenz Obs. in Tennessee, 1 in MPEC 2012-S79 -- P/2012 S2
I39Cruz del Sur Obs. in Argentina, 2 in MPEC 2012-S78 -- 2012 QF49, 159635
J95Great Shefford Obs. in England, 1 in MPEC 2012-S79 -- P/2012 S2
J75La Sagra Obs. in Spain, 1 in MPEC 2012-S79 -- P/2012 S2
H01Magdalena Ridge Obs. in New Mexico, 1 in MPEC 2012-S79 -- P/2012 S2
5682David Tholen's team on Mauna Kea in Hawaii, 1 in MPEC 2012-S78 -- 2008 GV3
711McDonald Obs. in Texas, 1 in MPEC 2012-S78 -- 2012 SY49
G96Mt. Lemmon Survey in Arizona, 1 in MPEC 2012-S78 -- 2012 RV16
F51Pan-STARRS 1 (PS1) in Hawaii, 3 in MPEC 2012-S78 -- 1998 SE36, 96536, 7888
B49Paus Obs. in Spain, 1 in MPEC 2012-S79 -- P/2012 S2
H06|Hidetaka Sato in Japan via RAS Obs. Mayhill in New Mexico, 1 in MPEC 2012-S79 -- P/2012 S2
H36Sandlot Obs. in Kansas, 1 in MPEC 2012-S79 -- P/2012 S2
291Spacewatch 1.8m telescope in Arizona, 7 in MPECs 2012-S78 & 2012-S79 -- 2012 SW20, 2012 SV20, 2012 ST9, P/2012 S2, 2012 RU16, 2012 QF42, 2010 VN65
718Wiggins Obs. in Utah, 1 in MPEC 2012-S78 -- 2012 JS11
For a list of all participating observatories that have Web addresses, see A/CC's Observatory Links page.

Impact Risk Monitoring  on 27 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 SY49JPL Sentry15092031-2084201.3e-05-5.09-5.460JPL: "Analysis based on 43 observations spanning 4.1465 days (2012-Sep-22.26616 to 2012-Sep-26.412676)." Diameter approximately 0.023 km. from mean, weighted H=25.8.
NEODyS15092031-2097151.14e-05-5.14-5.370NEODyS: "Based on 43 optical observations (of which 0 are rejected as outliers) from 2012-09-22.267 to 2012-09-26.413."
2012 SW20NEODyS1509R E M O V E D-
2012 RU16JPL Sentry15092032-210651.2e-06-6.47-6.720JPL: "Analysis based on 54 observations spanning 10.974 days (2012-Sep-15.34955 to 2012-Sep-26.32322)." Diameter approximately 0.025 km. from mean, weighted H=25.6.
NEODyS15092036-209944.63e-07-6.82-7.080NEODyS: "Based on 54 optical observations (of which 0 are rejected as outliers) from 2012-09-15.350 to 2012-09-26.324."

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 27 September '12

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

2100Grabbed MPEC 2012-S79 - Comet P/2012 S2 (La Sagra) - see above
1511Generated Traffic Report
1509Noted that JPL Sentry has updated its 2012 RU16 risk assessment - see above
Noted that NEODyS has updated its 2012 RU16 risk assessment - see above
Noted that NEODyS has removed 2012 SW20 as an impact risk - see above
Noted that JPL Sentry has updated its 2012 SY49 risk assessment - see above
Noted that NEODyS has updated its 2012 SY49 risk assessment - see above
Grabbed MPEC 2012-S78 - Daily Orbit Update - see above