Contents  on 31 December '11


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.

NEOCP Activity  on 31 December '11

The MPC's NEO Confirmation Page has 23 listings

When last checked at 2357 UTC today, the Minor Planet Center's Near Earth Object discovery Confirmation Page (NEOCP) had 23 objects listed. Of these, fifteen were "one nighters." So far The Tracking News has counted a total of 48 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 31 December '11

Minor Planet Electronic Circulars

As of last check at 2357 UTC, there have been five MPECs posted today from the International Astronomical Union's Minor Planet Center in Cambridge, Massachusetts. No Daily Orbit Update DOU MPEC has been posted yet, so visit the MPC Status Page for possible explanation.

MPEC 2011-Y71 - "17:21 UT" - 2011 YH40

MPEC 2011-Y70 - "16:57 UT" - 2011 YE40

MPEC 2011-Y69 - "16:55 UT" - 2011 YD40

MPEC 2011-Y68 - "16:53 UT" - 2011 YC40

MPEC 2011-Y67 - "16:51 UT" - 2011 YB40

Observers  on 31 December '11

Fourteen observers appear in today's MPECs.

CodeObserver / observatory
300Bisei Spaceguard Center in Japan, 1 in MPEC 2011-Y67 -- 2011 YB40
703Catalina Sky Survey (CSS) in Arizona, 3 in MPECs 2011-Y67, 2011-Y70 & 2011-Y71 -- 2011 YH40, 2011 YE40, 2011 YB40
G48Doc Greiner Research Obs. Rancho Hildalgo in New Mexico, 1 in MPEC 2011-Y71 -- 2011 YH40
595Farra d'Isonzo Obs. in Italy, 2 in MPECs 2011-Y67 & 2011-Y71 -- 2011 YH40, 2011 YB40
F65%Tim Lister in southern California via Faulkes Telescope North in Hawaii, 1 in MPEC 2011-Y69 -- 2011 YD40
J95Great Shefford Obs. in England, 1 in MPEC 2011-Y71 -- 2011 YH40
C32Ka-Dar Obs. TAU Station in Russia, 1 in MPEC 2011-Y67 -- 2011 YB40
704LINEAR in New Mexico, 1 in MPEC 2011-Y70 -- 2011 YE40
900Moriyama Obs. in Japan, 1 in MPEC 2011-Y71 -- 2011 YH40
G96Mt. Lemmon Survey (MLS) in Arizona, 2 in MPECs 2011-Y68 & 2011-Y69 -- 2011 YD40, 2011 YC40
854Sabino Canyon Obs. in Arizona, 2 in MPECs 2011-Y68 & 2011-Y70 -- 2011 YE40, 2011 YC40
H36Sandlot Obs. in Kansas, 1 in MPEC 2011-Y67 -- 2011 YB40
204Schiaparelli Obs. in Italy, 1 in MPEC 2011-Y71 -- 2011 YH40
291Spacewatch 1.8m telescope in Arizona, 3 in MPECs 2011-Y67, 2011-Y69 & 2011-Y71 -- 2011 YH40, 2011 YD40, 2011 YB40
For a list of all participating observatories that have Web addresses, see A/CC's Observatory Links page.

Impact Risk Monitoring  on 31 December '11

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
2011 YC40JPL Sentry19082028-205063.4e-06-7.33-7.410JPL: "Analysis based on 13 observations spanning 1.0493 days (2011-Dec-29.27153 to 2011-Dec-30.32086)." Diameter approximately 0.004 km. from mean, weighted H=29.7.

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 31 December '11

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

1908Noted that JPL Sentry has posted 2011 YC40 as an impact risk - see above
1735Grabbed MPEC 2011-Y71 - 2011 YH40 - see above
1706Grabbed MPEC 2011-Y67 - 2011 YB40 - see above
Grabbed MPEC 2011-Y68 - 2011 YC40 - see above
Grabbed MPEC 2011-Y69 - 2011 YD40 - see above
Grabbed MPEC 2011-Y70 - 2011 YE40 - see above