Voyager 1 has has found a region of zero solar wind speed 
in the heliosheath. Illustration credit: NASA/JPL.

NASA reports that, out beyond 115 AU, where only 90377 Sedna, long-period comets, and a few dozen "scattered disk" objects are known to travel, Voyager 1 has been passing through a region for several months now where solar wind speed is zero. It is believed that the heliosheath hasn't been crossed yet and interstellar space is four years' flight away. Illustration credit: NASA/JPL.


Contents  on 15 December '10

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 15 December '10

The MPC's NEO Confirmation Page has 14 listings: 2 new, 12 updated

When last checked at 2359 UTC today, the Minor Planet Center's Near Earth Object discovery Confirmation Page (NEOCP) had two new and twelve updated listings. Of these, six were "one nighters." So far The Tracking News has counted a total of eighteen listings on the NEOCP at some point 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 15 December '10

Minor Planet Electronic Circulars

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


MPEC 2010-X117 - "17:08 UT" - 2003 WP7 = 2010 WD3 = 2010 XK3


MPEC 2010-X116 - "17:03 UT" - 2003 WP7 = 2010 XK3


<< DOU on 15 Dec. '10 >>  MPEC 2010-X115 - "07:09 UT" - Daily Orbit Update


MPEC 2010-X114 - "05:59 UT" - 2010 XA68


MPEC 2010-X113 - "05:55 UT" - 2010 XZ67


MPEC 2010-X112 - "00:25 UT" - 2010 XG64


MPEC 2010-X111 - "00:15 UT" - 2010 XF64

Observers  on 15 December '10

Eighteen observers appear in today's MPECs.

CodeObserver / observatory
834AAAA Buenos Aires Obs. in Argentina, 1 in MPEC 2010-X115 -- 2006 VB14
H21Astronomical Research Obs. Westfield in Illinois, 16 in MPECs 2010-X113, 2010-X114 & 2010-X115 -- 2010 XZ67, 2010 XT45, 2010 XO56, 2010 XF3, 2010 XC25, 2010 XC15, 2010 XB24, 2010 XA68, 2010 XA59, 2010 WR7, 2010 VZ, 2010 VY190, 2010 TJ7, 2010 SD13, 2010 RR179, 2000 CR101
160Castelmartini Obs. in Italy, 3 in MPEC 2010-X115 -- 2010 WZ8, 2010 LF86, 2010 JL33
703Catalina Sky Survey (CSS) in Arizona, 12 in MPEC 2010-X115 -- 2010 XZ58, 2010 XF3, 2010 XC15, 1999 XR35, 231134, 219071, 177255, 138859, 11405, 100926, 5869, 1864
448Desert Moon Obs. in New Mexico, 6 in MPEC 2010-X115 -- 2010 XU45, 2010 XJ3, 2010 XG3, 2010 XG11, 2010 XC24, 162421
H20Eastern Illinois Univ. Obs. in Illinois, 11 in MPEC 2010-X115 -- 2010 XX58, 2010 WP8, 2010 LR68, 2010 JL33, 2007 EM88, 2006 VB14, 2005 WE, 2005 GC120, 2002 OS4, 2000 AC6, 1999 XR35
I19El Gato Gris Obs. in Argentina, 1 in MPEC 2010-X115 -- 2010 XB25
H15ISON-NM Obs. in New Mexico, 1 in MPEC 2010-X115 -- 2010 RN80
J28Jaen Obs. in Spain, 2 in MPEC 2010-X115 -- 2010 WL, 2010 JL33
704LINEAR in New Mexico, 14 in MPEC 2010-X115 -- 2010 XP51, 2010 XG3, 2010 XF3, 2010 WZ8, 2010 WL, 2010 WJ, 2010 VK188, 2007 EM88, 1997 XS2, 86324, 68278, 170086, 153814, 5496
844Los Molinos Obs. in Uruguay, 1 in MPEC 2010-X115 -- 2010 XM56
H01Magdalena Ridge Obs. (MRO) in New Mexico, 5 in MPECs 2010-X111, 2010-X112, 2010-X113, 2010-X114 & 2010-X115 -- 2010 XZ67, 2010 XG64, 2010 XF64, 2010 XA68, 2010 XA59
A06Mataro Obs. in Spain, 2 in MPEC 2010-X115 -- 2010 JL33, 2005 GC120
152Moletai Obs. in Lithuania, 1 in MPEC 2010-X115 -- 2010 KO10
G96Mt. Lemmon Survey (MLS) in Arizona, 6 in MPECs 2010-X111, 2010-X112, 2010-X114 & 2010-X115 -- 2010 XG64, 2010 XF64, 2010 XA68, 2010 KH, 2004 BV1, 170086
691Spacewatch 0.9m telescope in Arizona, 6 in MPECs 2010-X113 & 2010-X115 -- 2010 XZ67, 2010 XU45, 2010 XJ, 2010 XC24, 2010 UB8, 2000 AZ93
291Spacewatch 1.8m telescope in Arizona, 7 in MPECs 2010-X114 & 2010-X115 -- 2010 XO56, 2010 XC25, 2010 XA68, 2010 OC101, 2008 FT6, 2008 EJ1, 2005 CF41
C51WISE in Earth polar orbit, 4 in MPECs 2010-X113 & 2010-X115 -- 2010 XZ67, 2010 MY1, 247360, 154590
For a list of all participating observatories that have Web addresses, see A/CC's Observatory Links page.

Impact Risk Monitoring  on 15 December '10

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
2010 XA68JPL Sentry16002020-2108557.8e-07-3.94-4.330JPL: "Analysis based on 25 observations spanning 1.1563 days (2010-Dec-14.06285 to 2010-Dec-15.21919)." Diameter approximately 0.150 km. from mean, weighted H=21.7.
NEODyS16002024-2087272.7e-07-4.15-4.390NEODyS: "Based on 25 optical observations (of which 0 are rejected as outliers) from 2010-12-14.064 to 2010-12-15.220."
2010 XA59NEODyS1600R E M O V E D-
JPL Sentry1600R E M O V E DJPL: Risk listing removed at 1112 UTC.
2010 XO56JPL Sentry1600R E M O V E DJPL: Risk listing removed at 1123 UTC.
2010 XC25JPL Sentry16002024-2093322.0e-05-2.22-2.750JPL: "Analysis based on 40 observations spanning 6.0649 days (2010-Dec-08.37716 to 2010-Dec-14.442071)." Diameter approximately 0.262 km. from mean, weighted H=20.6.
NEODyS16002024-2090382.1e-05-2.19-2.730NEODyS: "Based on 40 optical observations (of which 0 are rejected as outliers) from 2010-12-08.378 to 2010-12-14.443."

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 15 December '10

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

1733Grabbed MPEC 2010-X116 - 2003 WP7 = 2010 XK3 - see above
Grabbed MPEC 2010-X117 - 2003 WP7 = 2010 WD3 = 2010 XK3 - see above
1600Noted that JPL Sentry has removed 2010 XA59 as an impact risk - see above
Noted that NEODyS has removed 2010 XA59 as an impact risk - see above
Noted that JPL Sentry has posted 2010 XA68 as an impact risk - see above
Noted that NEODyS has posted 2010 XA68 as an impact risk - see above
Noted that JPL Sentry has updated its 2010 XC25 risk assessment - see above
Noted that NEODyS has updated its 2010 XC25 risk assessment - see above
Noted that JPL Sentry has removed 2010 XO56 as an impact risk - see above
Grabbed MPEC 2010-X115 - Daily Orbit Update - see above
0603Grabbed MPEC 2010-X113 - 2010 XZ67 - see above
Grabbed MPEC 2010-X114 - 2010 XA68 - see above
0100Grabbed MPEC 2010-X112 - 2010 XG64 - see above
0028Grabbed MPEC 2010-X111 - 2010 XF64 - see above