Artistic visualization of tonight's Stardust 9P/Tempel 1 
encounter. Credit: NASA/JPL-Caltech.

An artistic visualization of tonight's Stardust-NExT encounter with comet 9P/Tempel 1, with closest passage at 0337 UTC tomorrow morning. Credit: NASA/JPL-Caltech. Update #2: See news items from the University of Chicago Friday and NASA today. NASA TV will have a live broadcast.

Contents  on 14 February '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 14 February '11

The MPC's NEO Confirmation Page has 3 listings: 3 updated

When last checked at 2359 UTC today, the Minor Planet Center's Near Earth Object discovery Confirmation Page (NEOCP) had three updated listings. Of these, one was a "one nighter." So far The Tracking News has counted a total of twelve 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 14 February '11

Minor Planet Electronic Circulars

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

MPEC 2011-C95 - "13:24 UT" - 2011 CG66

MPEC 2011-C94 - "13:20 UT" - 2011 CF66

MPEC 2011-C93 - "13:14 UT" - 2011 CE66

MPEC 2011-C92 - "13:10 UT" - 2011 CD66

<< DOU on 14 Feb. '11 >>  MPEC 2011-C91 - "07:10 UT" - Daily Orbit Update

Observers  on 14 February '11

Eight observers appear in today's MPECs.

CodeObserver / observatory
H21Astronomical Research Obs. Westfield in Illinois, 3 in MPEC 2011-C91 -- 2011 CZ6, 2011 CY7, 2011 AO52
J95Great Shefford Obs. in England, 1 in MPEC 2011-C92 -- 2011 CD66
704LINEAR in New Mexico, 2 in MPEC 2011-C91 -- 2011 BO59, 5869
B67Mirasteilas Obs. in Switzerland, 1 in MPEC 2011-C91 -- 2002 TD60
G96Mt. Lemmon Survey (MLS) in Arizona, 11 in MPECs 2011-C91, 2011-C92, 2011-C93, 2011-C94 & 2011-C95 -- 2011 CO2, 2011 CG66, 2011 CF66, 2011 CE66, 2011 CD66, 2011 CB50, 2011 BA12, 2005 GK, 241596, 208617, 7482
H06|H. Sato in Japan via RAS Obs. Mayhill in New Mexico, 2 in MPEC 2011-C91 -- 2009 QJ9, 3200
D90`Kevin Hills in England via RAS Obs. Moorook in South Australia, 1 in MPEC 2011-C91 -- 2011 AN16
291Spacewatch 1.8m telescope in Arizona, 8 in MPEC 2011-C91 -- 2011 CR4, 2011 CP4, 2011 CH50, 2011 CG33, 2011 CE50, 2011 BX18, 2011 BB45, 2011 AH37
For a list of all participating observatories that have Web addresses, see A/CC's Observatory Links page.

Impact Risk Monitoring  on 14 February '11

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 CLOMON (backup) risk pages.





Notes for Today's Latest Risk Assessments
2011 CL50NEODyS15482031-2090531.02e-05-6.40-6.760NEODyS: "Based on 16 optical observations (of which 0 are rejected as outliers) from 2011-02-12.463 to 2011-02-13.387."
JPL Sentry03142040-21102153.3e-05-6.13-6.830JPL: "Analysis based on 16 observations spanning .92353 days (2011-Feb-12.46221 to 2011-Feb-13.38574)." Diameter approximately 0.010 km. from mean, weighted H=27.6.
2011 CJ50NEODyS15482029-208453.54e-08-4.62-4.930NEODyS: "Based on 19 optical observations (of which 0 are rejected as outliers) from 2011-02-11.499 to 2011-02-13.550."
2011 CB50JPL Sentry15482041-210946.5e-08-5.31-5.730JPL: "Analysis based on 19 observations spanning 3.0561 days (2011-Feb-10.48858 to 2011-Feb-13.54466)." Diameter approximately 0.261 km. from mean, weighted H=20.6.
NEODyS15482041-204114.6e-09-6.01-6.010NEODyS: "Based on 19 optical observations (of which 0 are rejected as outliers) from 2011-02-10.489 to 2011-02-13.545."
2011 BA12JPL Sentry15482079-211043.2e-08-6.66-6.920JPL: "Analysis based on 141 observations spanning 19.122 days (2011-Jan-25.1938 to 2011-Feb-13.31567)." Diameter approximately 0.100 km. from mean, weighted H=22.6.

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 14 February '11

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

1548Noted that JPL Sentry has updated its 2011 BA12 risk assessment - see above
Noted that JPL Sentry has updated its 2011 CB50 risk assessment - see above
Noted that NEODyS has updated its 2011 CB50 risk assessment - see above
Noted that NEODyS has posted 2011 CJ50 as an impact risk - see above
Noted that NEODyS has posted 2011 CL50 as an impact risk - see above
Grabbed MPEC 2011-C91 - Daily Orbit Update - see above
Grabbed MPEC 2011-C92 - 2011 CD66 - see above
Grabbed MPEC 2011-C93 - 2011 CE66 - see above
Grabbed MPEC 2011-C94 - 2011 CF66 - see above
Grabbed MPEC 2011-C95 - 2011 CG66 - see above
0314Noted that JPL Sentry has posted 2011 CL50 as an impact risk - see above