Contents  on 2 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 2 April '12

Nine objects reported inside ten LD

There are nine asteroids reported moving inside ten lunar distances (LD) of Earth today. Within Earth's Hill sphere, radar target intruder 2012 EG5 is headed away from 1.29 to 3.08 LD. More distantly, risk-listed 2012 FA57 is inbound from 6.08 to 4.08 LD and 2012 FH58 from 5.52 to 4.14 LD. 2012 FQ62 comes its closest to Earth on this passage, reaching 5.65 LD at 1953 UTC, as does 2012 FS52, coming to 8.87 LD at 2040 UTC. Intruder 2012 FS35 is outbound from 4.94 to 5.71 LD, 2012 FV23 from 7.61 to 8.39 LD, 2012 FT35 from 8.30 to 9.26 LD, and 2012 FW35 from 8.4 to 9.0 LD*.

Coming our way next, newly discovered 2012 GD arrives inside ten LD on April 8th and returning 2007 HV4 comes inside on April 14th.

This report was updated at 2209 UTC with new discoveries 2012 GD (MPEC) and already departed 2012 GE (MPEC) and 2012 FA71 (MPEC). Earlier, follow-up was reported in today's DOU MPEC for 2012 FQ62 and distant 2011 CP4. Today's first traffic report was posted at 1501 UTC.

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. "LD*" indicates some passage uncertainty. See also current sky chart and object details (alt-details), ephemerides, and today's timeline.

Radar Astrometry  on 2 April '12

Radar observation of one object

The JPL Solar System Dynamics Group Radar Astrometry database has added or updated the following small-body radar observing work:

Data update noted at 2035 UTC when the database was dated 2 April

NEOCP Activity  on 2 April '12

The MPC's NEO Confirmation Page has 13 listings

When last checked at 2359 UTC today, the Minor Planet Center's Near Earth Object discovery Confirmation Page (NEOCP) had thirteen objects listed. Of these, seven were "one nighters." So far The Tracking News has counted a total of 28 listings on the NEOCP today.

New MPECs  on 2 April '12

Minor Planet Electronic Circulars

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

MPEC 2012-G16 - "20:16 UT" - 2012 GE

MPEC 2012-G15 - "20:15 UT" - 2012 GD

MPEC 2012-G14 - "20:13 UT" - 2012 GC

MPEC 2012-G13 - "20:11 UT" - 2012 FC71

MPEC 2012-G12 - "20:09 UT" - 2012 FB71

MPEC 2012-G11 - "20:07 UT" - 2012 FA71

<< DOU on 2 Apr. '12 >>  MPEC 2012-G10 - "06:04 UT" - Daily Orbit Update

Observers  on 2 April '12

Nineteen observers appear in today's MPECs.

CodeObserver / observatory
251Arecibo in Puerto Rico, 1 in radar -- 2201
H21Astronomical Research Obs. Westfield in Illinois, 7 in MPECs 2012-G10 & 2012-G16 -- 2012 GE, 2012 FZ23, 2012 FB57, 2012 EA2, 2012 AA11, 2011 QD48, 2004 QJ7
I47Auger Obs. in Argentina, 2 in MPEC 2012-G10 -- 2012 FD23, 152754
B88Bigmuskie Obs. in Italy, 3 in MPEC 2012-G10 -- 2012 ES14, 2011 QD48, 138359
300Bisei Spaceguard Center in Japan, 3 in MPEC 2012-G10 -- 2011 CP4, 2008 QY, 162421
703Catalina Sky Survey (CSS) in Arizona, 9 in MPEC 2012-G10 -- 2012 EL5, 2011 SL102, 2008 JZ30, 2004 QJ7, 2002 EM6, 36183, 317643, 141018, 138095
807|Robert Holmes in Illinois via Cerro Tololo Inter-American Obs. (CTIO) in Chile, 5 in MPEC 2012-G10 -- 2012 FZ44, 2012 FR1, 2012 FP62, 2012 FO62, 2012 FG58
106Crni Vrh Obs. in Slovenia, 1 in MPEC 2012-G10 -- 263976
J95Great Shefford Obs. in England, 3 in MPECs 2012-G10, 2012-G14 & 2012-G16 -- 2012 GE, 2012 GC, 2012 FQ62
H15ISON-NM Obs. in New Mexico, 1 in MPEC 2012-G10 -- 2012 FZ23
704LINEAR in New Mexico, 8 in MPEC 2012-G10 -- 2012 FY23, 2012 DO, 2004 FF29, 68348, 312473, 155334, 144411, 7341
844Los Molinos Obs. in Uruguay, 3 in MPEC 2012-G10 -- 2012 DO, 152754, 5587
5682David Tholen's team on Mauna Kea in Hawaii, 3 in MPECs 2012-G10, 2012-G11 & 2012-G12 -- 2012 FS62, 2012 FB71, 2012 FA71
G96Mt. Lemmon Survey (MLS) in Arizona, 8 in MPECs 2012-G10, 2012-G13, 2012-G14, 2012-G15 & 2012-G16 -- 2012 GE, 2012 GD, 2012 GC, 2012 FW23, 2012 FC71, 2005 CJ, 143381, 3271
A24New Millennium Obs. in Italy, 1 in MPEC 2012-G10 -- 6455
F51Pan-STARRS 1 (PS1) in Hawaii, 5 in MPECs 2012-G10, 2012-G11 & 2012-G12 -- 2012 FB71, 2012 FA71, 318050, 154555, 7977
E12Siding Spring Survey (SSS) in New South Wales, 10 in MPEC 2012-G10 -- 2012 FY23, 2012 FD23, 2012 DW30, 86039, 68548, 68348, 144411, 141056, 7341, 1685
691Spacewatch 0.9m telescope in Arizona, 4 in MPEC 2012-G10 -- 2012 DX32, 189008, 186822, 162422
291Spacewatch 1.8m telescope in Arizona, 13 in MPECs 2012-G10, 2012-G11, 2012-G12 & 2012-G13 -- 2012 FR1, 2012 FP62, 2012 FL35, 2012 FG58, 2012 FD1, 2012 FC71, 2012 FB71, 2012 FA71, 2012 ES14, 2012 DN14, 2010 LR33, 2010 FQ, 2001 RQ3
For a list of all participating observatories that have Web addresses, see A/CC's Observatory Links page.

Impact Risk Monitoring  on 2 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 GDJPL Sentry23182020-21102394.9e-06-6.16-6.680JPL: "Analysis based on 12 observations spanning .99029 days (2012-Apr-01.34437 to 2012-Apr-02.33466)." Diameter approximately 0.013 km. from mean, weighted H=27.0.
2012 FB71JPL Sentry21562069-207721.1e-09-8.36-8.460JPL: "Analysis based on 8 observations spanning 3.8652 days (2012-Mar-29.46274 to 2012-Apr-02.32793)." Diameter approximately 0.050 km. from mean, weighted H=24.2.
2012 FR1NEODyS1500R 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 2 April '12

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

2318Noted that JPL Sentry has posted 2012 GD as an impact risk - see above
2209Updated Traffic Report
2156Noted that JPL Sentry has posted 2012 FB71 as an impact risk - see above
2035Grabbed MPEC 2012-G11 - 2012 FA71 - see above
Grabbed MPEC 2012-G12 - 2012 FB71 - see above
Grabbed MPEC 2012-G13 - 2012 FC71 - see above
Grabbed MPEC 2012-G14 - 2012 GC - see above
Grabbed MPEC 2012-G15 - 2012 GD - see above
Grabbed MPEC 2012-G16 - 2012 GE - see above
Noted Radar Astrometry database update - see above
1500Noted that NEODyS has removed 2012 FR1 as an impact risk - see above
Grabbed MPEC 2012-G10 - Daily Orbit Update - see above