Contents  on 11 March '13

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 11 March '13

Four objects reported inside ten LD

Four objects are reported to be within ten lunar distances (LD) of our planet today. Outbound radar target and intruder, 2013 EC20, was within one LD of the Moon until 0136 UT. Also inside Earth's Hill sphere, 2013 EN20 came its closest to the Moon on this passage, reaching about 1.6 LD at around 0134 UT (Earth passage uncertainty: +/- 21 minutes).

More distantly, radar target 2013 ET is outbound from 4.72 to 7.12 LD and newly announced 2013 EA29 comes inside ten LD, passing from 12.59 to 9.49 LD.

Coming into the neighborhood next, risk-listed radar target 2010 EO88 arrives inside ten LD on March 15th and risk-listed 2013 ES11 arrives on March 19th.

This report was generated at 1459 UTC with new discovery 2013 EA29 (MPEC) and first follow-up for 2013 ES11 (expanding its observing arc from 2.115 to 4.798 days) in today's DOU MPEC, which also carries observations from a month ago of 2013 BD74 and risk-listed intruder 2013 CY.

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.

Radar Astrometry  on 11 March '13

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 2326 UTC when the database was dated 11 March

NEOCP Activity  on 11 March '13

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, fourteen were "one nighters." So far The Tracking News has counted a total of 20 listings on the NEOCP today.

New MPECs  on 11 March '13

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 2013-E49 - "11:53 UT" - 2013 EA29

MPEC 2013-E48 - "10:46 UT" - 2011 UW158

<< DOU on 11 Mar. '13 >>  MPEC 2013-E47 - "06:05 UT" - Daily Orbit Update

MPEC 2013-E46 - "01:41 UT" - Comet P/2013 CE31 (MOSS)

Observers  on 11 March '13

Fifteen observers appear in today's MPECs.

CodeObserver / observatory
703Catalina Sky Survey in Arizona, 1 in MPEC 2013-E49 -- 2013 EA29
807|Robert Holmes in Illinois via Cerro Tololo Inter-American Obs. (CTIO) in Chile, 10 in MPECs 2013-E47 & 2013-E48 -- 2013 EY27, 2013 ET9, 2013 ES9, 2013 ES11, 2013 EC28, 2013 EA, 2013 DM1, 2011 UW158, 2007 EL88, 2005 GO22
253Goldstone DSS-14 70m antenna in southern California, 1 in radar -- 2013 ET
511Haute Provence Obs. in Germany, 1 in MPEC 2013-E46 -- P/2013 CE31
H15ISON-NM Obs. in New Mexico, 2 in MPEC 2013-E47 -- 22771, 7358
5682David Tholen's team on Mauna Kea in Hawaii, 1 in MPEC 2013-E47 -- 2013 BP73
644NEAT's Mt. Palomar telescope in southern California, 1 in MPEC 2013-E46 -- P/2013 CE31
608NEAT's USAF Haleakala telescope in Hawaii, 1 in MPEC 2013-E46 -- P/2013 CE31
F51Pan-STARRS 1 (PS1) in Hawaii, 2 in MPECs 2013-E47 & 2013-E49 -- 2013 EA29, 2009 BL2
204Schiaparelli Obs. in Italy, 13 in MPEC 2013-E47 -- 2013 CY, 2013 CV83, 2013 CU82, 2013 CN129, 2013 BE74, 2013 BD74, 2013 AW60, 2013 AM60, 2012 VL94, 2009 DK46, 2008 CJ70, 2008 CA5, 1999 UR
033Schwarzschild Obs. in Germany, 3 in MPEC 2013-E47 -- 2013 ES11, 2013 EM20, 2013 EL28
691Spacewatch 0.9m telescope in Arizona, 1 in MPEC 2013-E46 -- P/2013 CE31
291Spacewatch 1.8m telescope in Arizona, 1 in MPEC 2013-E47 -- 2013 EQ
G56Walnut Creek Obs. in northern California, 1 in MPEC 2013-E47 -- 2013 EA
718Wiggins Obs. in Utah, 1 in MPEC 2013-E47 -- 2013 EA
For a list of all participating observatories that have Web addresses, see A/CC's Observatory Links page.

Impact Risk Monitoring  on 11 March '13

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
2013 EL28JPL Sentry13452018-2107392.1e-08-6.14-6.230JPL: "Analysis based on 12 observations spanning 1.5801 days (2013-Mar-08.60533 to 2013-Mar-10.1854)." Diameter approximately 0.094 km. from mean, weighted H=22.8.
2013 ES11NEODyS1345R E M O V E D-
JPL Sentry1345R E M O V E DJPL: Risk listing removed at 0954 UTC.
2013 CYJPL Sentry13452069-209152.5e-06-7.51-7.980JPL: "Analysis based on 82 observations spanning 18.061 days (2013-Feb-01.34874 to 2013-Feb-19.40959)." Diameter approximately 0.008 km. from mean, weighted H=28.2.
NEODyS13452072-209172.83e-06-7.48-7.970NEODyS: "Based on 82 optical observations (of which 0 are rejected as outliers) from 2013-02-01.350 to 2013-02-19.410."
2013 BP73JPL Sentry17322090-210761.3e-05-2.55-2.571JPL: "Analysis based on 32 observations spanning 45.988 days (2013-Jan-22.24343 to 2013-Mar-09.231013)." Diameter approximately 0.310 km. from mean, weighted H=20.2.
NEODyS13452086-211288.94e-06-2.71-2.740NEODyS: "Based on 32 optical observations (of which 0 are rejected as outliers) from 2013-01-22.244 to 2013-03-09.232."

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 11 March '13

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

2326Noted Radar Astrometry database update - see above
1732Noted that JPL Sentry has updated its 2013 BP73 risk assessment - see above
1459Generated Traffic Report
1345Noted that NEODyS has updated its 2013 BP73 risk assessment - see above
Noted that JPL Sentry has updated its 2013 CY risk assessment - see above
Noted that NEODyS has updated its 2013 CY risk assessment - see above
Noted that JPL Sentry has updated its 2013 EL28 risk assessment - see above
Noted that JPL Sentry has removed 2013 ES11 as an impact risk - see above
Noted that NEODyS has removed 2013 ES11 as an impact risk - see above
Grabbed MPEC 2013-E47 - Daily Orbit Update - see above
Grabbed MPEC 2013-E48 - 2011 UW158 - see above
Grabbed MPEC 2013-E49 - 2013 EA29 - see above
0153Grabbed MPEC 2013-E46 - Comet P/2013 CE31 (MOSS) - see above