Rosetta spacecraft visualization. 
Credit ESA, image by AOES Medialab.

The ESA Rosetta blog yesterday reported a successful resolution to a failed January 18th thruster burn. The fix "enables the spacecraft to perform even better than before" and the spacecraft is now "more or less lined up to meet Comet 67P/Churyumov-Gerasimenko in 2014." See more info here. Credit: ESA, illustration by AOES Medialab.

Contents  on 23 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 23 February '11

The MPC's NEO Confirmation Page has 9 listings: 1 new, 8 updated

When last checked at 2320 UTC today, the Minor Planet Center's Near Earth Object discovery Confirmation Page (NEOCP) had one new and eight updated listings. Of these, two were "one nighters." The Tracking News counted a total of eleven listings on the NEOCP on this day.

New MPECs  on 23 February '11

Minor Planet Electronic Circulars

There were seven MPECs posted this day from the International Astronomical Union's Minor Planet Center in Cambridge, Massachusetts.

MPEC 2011-D29 - "23:56 UT" - 2011 DQ

MPEC 2011-D28 - "23:51 UT" - 2011 DP

MPEC 2011-D27 - "23:47 UT" - 2011 DO

MPEC 2011-D26 - "23:43 UT" - 2011 BA60

MPEC 2011-D25 - "20:44 UT" - 2011 CG71

MPEC 2011-D24 - "11:55 UT" - 2011 CH71

<< DOU on 23 Feb. '11 >>  MPEC 2011-D23 - "07:06 UT" - Daily Orbit Update

Observers  on 23 February '11

Sixteen observers appeared in this day's MPECs.

CodeObserver / observatory
300Bisei Spaceguard Center in Japan, 1 in MPEC 2011-D27 -- 2011 DO
235CAST Obs. in Italy, 1 in MPEC 2011-D27 -- 2011 DO
703Catalina Sky Survey (CSS) in Arizona, 5 in MPECs 2011-D24, 2011-D25, 2011-D27, 2011-D28 & 2011-D29 -- 2011 DQ, 2011 DP, 2011 DO, 2011 CH71, 2011 CG71
113Drebach Obs. in Germany, 2 in MPECs 2011-D27 & 2011-D28 -- 2011 DP, 2011 DO
595Farra d'Isonzo Obs. in Italy, 2 in MPECs 2011-D27 & 2011-D29 -- 2011 DQ, 2011 DO
379Hamamatsu-Yuto Obs. in Japan, 2 in MPEC 2011-D23 -- 2011 CG2, 3122
H15ISON-NM Obs. in New Mexico, 4 in MPECs 2011-D23, 2011-D24 & 2011-D27 -- 2011 DO, 2011 CH71, 2009 AV, 2006 CJ
5682David Tholen's team on Mauna Kea in Hawaii, 1 in MPEC 2011-D26 -- 2011 BA60
152Moletai Obs. in Lithuania, 1 in MPEC 2011-D23 -- 2010 PM10
F51Pan-STARRS 1 in Hawaii, 1 in MPEC 2011-D26 -- 2011 BA60
H36Sandlot Obs. in Kansas, 2 in MPEC 2011-D23 -- 2011 CM50, 2011 CH33
204Schiaparelli Obs. in Italy, 1 in MPEC 2011-D23 -- 2008 EE
291Spacewatch 1.8m telescope in Arizona, 16 in MPEC 2011-D23 -- 2011 CT4, 2011 CS4, 2011 CQ4, 2011 CO2, 2011 CN2, 2011 CH33, 2011 BX59, 2011 BX18, 2011 BT15, 2011 BM24, 2011 BG40, 2011 BB45, 2011 BA45, 2011 BA12, 2011 AW55, 2011 AS26
H10Tzec Maun Obs. Mayhill in New Mexico, 1 in MPEC 2011-D24 -- 2011 CH71
G56Walnut Creek Obs. in northern California, 4 in MPECs 2011-D23, 2011-D24 & 2011-D25 -- 2011 CH71, 2011 CG71, 2004 CK39, 2002 SZ
I15Wishing Star Obs. in Rhode Island, 6 in MPEC 2011-D23 -- 2011 CY46, 2011 CG2, 2011 BO59, 2011 BA12, 68350, 137052
For a list of all participating observatories that have Web addresses, see A/CC's Observatory Links page.

Impact Risk Monitoring  on 23 February '11

Summary Risk Table for Risk Assessments Updated Today   (last checks: NEODyS and JPL at 2320 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 BT15JPL Sentry16202037-21101179.0e-05-2.87-3.870JPL: "Analysis based on 44 observations spanning 29.861 days (2011-Jan-24.28933 to 2011-Feb-23.15068)." Diameter approximately 0.140 km. from mean, weighted H=21.9.
NEODyS16202037-2090634.35e-05-3.12-3.760NEODyS: "Based on 45 optical observations (of which 3 are rejected as outliers) from 2011-01-24.290 to 2011-02-23.151."

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 23 February '11

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

0006 2/24Grabbed MPEC 2011-D26 - 2011 BA60 - see above
Grabbed MPEC 2011-D27 - 2011 DO - see above
Grabbed MPEC 2011-D28 - 2011 DP - see above
Grabbed MPEC 2011-D29 - 2011 DQ - see above
2123Grabbed MPEC 2011-D25 - 2011 CG71 - see above
1620Noted that JPL Sentry has updated its 2011 BT15 risk assessment - see above
Noted that NEODyS has updated its 2011 BT15 risk assessment - see above
Grabbed MPEC 2011-D23 - Daily Orbit Update - see above
Grabbed MPEC 2011-D24 - 2011 CH71 - see above