Contents  on 28 February '11

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.

NEOCP Activity  on 28 February '11

The MPC's NEO Confirmation Page has 6 listings: 4 new, 2 updated

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

New MPECs  on 28 February '11

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.


<< DOU on 28 Feb. '11 >>  MPEC 2011-D49 - "07:07 UT" - Daily Orbit Update


MPEC 2011-D48 - "03:18 UT" - 2010 ET65

Observers  on 28 February '11

Ten observers appear in today's MPECs.

CodeObserver / observatory
J16An Carraig Obs. in Northern Ireland, 2 in MPEC 2011-D49 -- 68350, 36284
I99Blanquita Obs. in Spain, 3 in MPEC 2011-D49 -- 2011 CH71, 2011 CG2, 3122
F65%T. Lister via Faulkes Telescope North in Hawaii, 2 in MPEC 2011-D49 -- 2011 DY4, 2011 DS9
157Frasso Sabino Obs. in Italy, 4 in MPEC 2011-D49 -- 2011 DY4, 2011 CY46, 2011 CH71, 2011 BA12
J28Jaen Obs. in Spain, 1 in MPEC 2011-D49 -- 48603
704LINEAR in New Mexico, 3 in MPEC 2011-D49 -- 2011 BO59, 2001 DQ8, 215167
J75La Sagra Obs. in Spain, 1 in MPEC 2011-D49 -- 3199
118Modra Obs. in Slovakia, 1 in MPEC 2011-D49 -- 2011 DD5
474Mt. John Obs. in New Zealand, 10 in MPEC 2011-D49 -- 2011 DY4, 2011 DU, 2011 DS9, 2011 DS, 2011 DE5, 2011 CM50, 2011 CG2, 2011 BX59, 2011 BR15, 2010 WZ8
644NEAT's Mt. Palomar telescope in southern California, 1 in MPEC 2011-D48 -- 2010 ET65
For a list of all participating observatories that have Web addresses, see A/CC's Observatory Links page.

Impact Risk Monitoring  on 28 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.
0000NNN000

Object

Risk
Monitor
When
Noted
UTC
0000T0000
Year
Range

VI
#
000NN00
Prob
Cum
T0000
PS
Cum
T0000
PS
Max

T
S


Notes for Today's Latest Risk Assessments
2011 DU9NEODyS16542022-2082218.36e-05-4.55-4.930NEODyS: "Based on 21 optical observations (of which 0 are rejected as outliers) from 2011-02-27.018 to 2011-02-27.589."
JPL Sentry01002022-2082258.5e-05-4.56-4.910JPL: "Analysis based on 21 observations spanning .57180 days (2011-Feb-27.01686 to 2011-Feb-27.58866)." Diameter approximately 0.016 km. from mean, weighted H=26.6.
2011 DS9JPL Sentry16542015-21102142.5e-06-2.69-3.020JPL: "Analysis based on 26 observations spanning 1.6383 days (2011-Feb-25.92799 to 2011-Feb-27.56632)." Diameter approximately 0.329 km. from mean, weighted H=20.1.
NEODyS16542015-20891101.63e-06-2.84-3.170NEODyS: "Based on 26 optical observations (of which 0 are rejected as outliers) from 2011-02-25.929 to 2011-02-27.567."
2011 DE5JPL Sentry16542018-209832.6e-05-4.30-4.300JPL: "Analysis based on 20 observations spanning 2.1788 days (2011-Feb-25.33918 to 2011-Feb-27.51803)." Diameter approximately 0.018 km. from mean, weighted H=26.4.
NEODyS16542018-205842.54e-05-4.31-4.310NEODyS: "Based on 20 optical observations (of which 0 are rejected as outliers) from 2011-02-25.340 to 2011-02-27.519."
2011 DSJPL Sentry16542065-2108191.8e-05-6.06-6.300JPL: "Analysis based on 33 observations spanning 4.0801 days (2011-Feb-23.39905 to 2011-Feb-27.47917)." Diameter approximately 0.013 km. from mean, weighted H=27.1.
NEODyS16542065-2089111.49e-05-6.13-6.310NEODyS: "Based on 33 optical observations (of which 0 are rejected as outliers) from 2011-02-23.400 to 2011-02-27.480."

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 28 February '11

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

1654Noted that JPL Sentry has updated its 2011 DE5 risk assessment - see above
Noted that NEODyS has updated its 2011 DE5 risk assessment - see above
Noted that JPL Sentry has updated its 2011 DS risk assessment - see above
Noted that NEODyS has updated its 2011 DS risk assessment - see above
Noted that JPL Sentry has updated its 2011 DS9 risk assessment - see above
Noted that NEODyS has updated its 2011 DS9 risk assessment - see above
Noted that NEODyS has posted 2011 DU9 as an impact risk - see above
Grabbed MPEC 2011-D49 - Daily Orbit Update - see above
0325Grabbed MPEC 2011-D48 - 2010 ET65 - see above
0100Noted that JPL Sentry has posted 2011 DU9 as an impact risk - see above