PI Mark Boslough explaining the Tunguska fireball. 
Photo by Randy Montoya, courtesy Sandia Natl. Labs.

Quote: "The stunning amount of forest devastation at Tunguska a century ago in Siberia may have been caused by an asteroid only a fraction as large as previously published estimates, Sandia National Laboratories supercomputer simulations suggest." Principal investigator Mark Boslough is shown explaining a fireball simulation. Photo by Randy Montoya, courtesy of Sandia National Labs, which has more info and movies.


Contents  on 19 December '07

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 this year 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 19 December '07

The MPC's NEO Confirmation Page has 5 listings: 4 new, 1 updated

When last checked at 2354 UTC today, the Minor Planet Center's NEO discovery Confirmation Page (NEOCP) had four new and one updated listings. All of these were "one nighters." So far The Tracking News has counted a total of eighteen objects listed on the NEOCP at some point today.

To learn how observers use the NEOCP, see the Practical guide on how to observe NEOCP object by Birtwhistle et al. at Suno Observatory.

New MPECs  on 19 December '07

Minor Planet Electronic Circulars

As of last check at 2354 UTC, there have been three MPECs issued today from the International Astronomical Union's Minor Planet Center in Cambridge, Massachusetts.


MPEC 2007-Y32 - "18:21 UT" - 2007 YB2


MPEC 2007-Y31 - "14:45 UT" - 2007 YX1


<< DOU on 19 Dec. '07 >>  MPEC 2007-Y30 - "07:10 UT" - Daily Orbit Update

Observers  on 19 December '07

A total of 23 observing facilities appear in today's MPECs.

CodeObserver / observatory
300Bisei Spaceguard Center in Japan, 1 in MPEC 2007-Y30 -- 2007 YZ
703Catalina Sky Survey (CSS) in Arizona, 23 in MPECs 2007-Y30, 2007-Y31 & 2007-Y32 -- 2007 YX1, 2007 YB2, 2007 XC10, 2007 WV3, 2007 UX1, 2007 TG15, 2007 SP6, 2007 LQ19, 2002 CC19, 1998 YM4, 90403, 21374, 170903, 154347, 152942, 144922, 137084, 11405, 3691, 3553, 3288, 1862, 1580
448Desert Moon Obs. in New Mexico, 8 in MPEC 2007-Y30 -- 2007 WW4, 2007 WV4, 2007 WV3, 2007 VW137, 2007 VH184, 2005 UB, 154347, 140288
595Farra d'Isonzo Obs. in Italy, 2 in MPECs 2007-Y31 & 2007-Y32 -- 2007 YX1, 2007 YB2
651Grasslands Obs. in Arizona, 1 in MPEC 2007-Y30 -- 2007 XF25
A17Guidestar Obs. in Germany, 1 in MPEC 2007-Y30 -- 2007 XT3
379Hamamatsu-Yuto Obs. in Japan, 3 in MPEC 2007-Y30 -- 2007 VQ4, 2007 SP6, 2003 BH84
A21Irmtraut Obs. in Germany, 2 in MPECs 2007-Y30 & 2007-Y31 -- 2007 YX1, 2007 YM1
701Junk Bond Obs. in Arizona, 2 in MPEC 2007-Y30 -- 2007 YG1, 2007 YF1
246KLENOT in the Czech Republic, 4 in MPEC 2007-Y30 -- 2007 YZ, 2007 YN1, 2007 XY9, 2007 XP3
704LINEAR in New Mexico, 13 in MPEC 2007-Y30 -- 2007 YZ, 2007 YH, 2007 XT3, 1998 YM4, 90403, 66959, 66251, 65706, 23548, 21374, 3691, 1862, 1580
699LONEOS in Arizona, 2 in MPEC 2007-Y30 -- 68063, 25916
H01Magdalena Ridge Obs. in New Mexico, 1 in MPEC 2007-Y30 -- 2007 XF25
711McDonald Obs. in Texas, 5 in MPECs 2007-Y30, 2007-Y31 & 2007-Y32 -- 2007 YX1, 2007 YB2, 2007 XK11, 2007 VX137, 2007 VR183
G96Mt. Lemmon Survey (MLS) in Arizona, 14 in MPECs 2007-Y30 & 2007-Y32 -- 2007 YB2, 2007 XY9, 2007 XN3, 2007 XJ20, 2007 WU4, 2007 VW137, 2007 VG189, 2007 TX18, 2007 TG15, 53319, 34613, 20460, 169675, 155334
461SZTE Asteroid Program (SZTE) in Hungary, 4 in MPECs 2007-Y30 & 2007-Y31 -- 2007 YX1, 2007 XT3, 2003 XL, 1989 AZ
B04Saint-Barthelemy Obs. in Italy, 2 in MPEC 2007-Y30 -- 2007 XH16, 2003 BH84
204Schiaparelli Obs. in Italy, 3 in MPEC 2007-Y30 -- 2007 XH16, 2007 XF18, 2003 BH84
510Siegen Obs. in Germany, 2 in MPEC 2007-Y30 -- 86324, 4954
691Spacewatch 0.9m telescope in Arizona, 12 in MPEC 2007-Y30 -- 2007 XT3, 2007 XP3, 2007 XD10, 2007 XB10, 2007 WY3, 2007 OG3, 2003 WL25, 2002 XY4, 2002 TC70, 1991 JW, 18736, 153201
291Spacewatch 1.8m telescope in Arizona, 2 in MPEC 2007-Y30 -- 2007 XD10, 2007 MK13
6734program code 4 via Table Mtn. Obs. in southern California, 1 in MPEC 2007-Y30 -- 2005 WJ56
F85Tiki Obs. in Tahiti, 1 in MPEC 2007-Y30 -- 2007 XH16

Impact Risk Monitoring  on 19 December '07

Summary Risk Table for Risk Assessments Updated Today   (last checks: NEODyS and JPL at 2354 UTC)
See the CRT page for a list of all objects rated recently as risks.
Note that the time horizon for JPL is 100 years from today and for NEODyS is now usually the year 2090.
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
2007 YB2JPL Sentry23102016-21071041.1e-07-3.22-4.060JPL: "Analysis based on 15 observations spanning 1.1144 days (2007-Dec-18.34552 to 2007-Dec-19.45988)." Diameter approximately 0.910 km. from mean, weighted H=17.9.
2007 YN1NEODyS1440208118.76e-09-8.07-8.070NEODyS: "Based on 17 optical observations (of which 1 are rejected as outliers) from 2007/12/18.311 to 2007/12/18.923."
2007 YH1NEODyS14402024-205952.85e-09-7.98-8.350NEODyS: "Based on 11 optical observations (of which 0 are rejected as outliers) from 2007/12/17.434 to 2007/12/18.338."
JPL Sentry02282024-2079121.1e-08-7.69-8.310JPL: "Analysis based on 11 observations spanning .90366 days (2007-Dec-17.43343 to 2007-Dec-18.33709)." Diameter approximately 0.041 km. from mean, weighted H=24.6.
2007 YG1NEODyS16162017-202821.97e-10-5.19-5.270NEODyS: "Based on 21 optical observations (of which 0 are rejected as outliers) from 2007/12/16.456 to 2007/12/18.531."
JPL Sentry14402019-204723.2e-10-5.30-5.510JPL: "Analysis based on 21 observations spanning 2.0744 days (2007-Dec-16.45543 to 2007-Dec-18.52985)." Diameter approximately 1.200 km. from mean, weighted H=17.3.
2007 XF25JPL Sentry1440R E M O V E DJPL: Risk listing removed at 1054 UTC.
NEODyS1440R E M O V E D
2007 XB23JPL Sentry01462078-208726.6e-07-7.56-7.810JPL: "Analysis based on 10 observations spanning .91734 days (2007-Dec-14.56193 to 2007-Dec-15.47927)." Diameter approximately 0.013 km. from mean, weighted H=27.1.
2007 XK11JPL Sentry14402064-210121.5e-07-4.18-4.250JPL: "Analysis based on 44 observations spanning 12.063 days (2007-Dec-06.0886 to 2007-Dec-18.15158)." Diameter approximately 0.496 km. from mean, weighted H=19.2.
NEODyS14402045-206421.16e-07-4.25-4.250NEODyS: "Based on 45 optical observations (of which 1 are rejected as outliers) from 2007/12/06.089 to 2007/12/18.158."

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 19 December '07

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

2310Noted that JPL Sentry has posted 2007 YB2 as an impact risk - see above
1832Grabbed MPEC 2007-Y32 - 2007 YB2 - see above
1616Noted that NEODyS has posted 2007 YG1 as an impact risk - see above
1527Grabbed MPEC 2007-Y31 - 2007 YX1 - see above
1441Grabbed MPEC 2007-Y30 - Daily Orbit Update - see above
1440Noted that JPL Sentry has removed 2007 XF25 as an impact risk - see above
Noted that NEODyS has removed 2007 XF25 as an impact risk - see above
Noted that JPL Sentry has updated its 2007 XK11 risk assessment - see above
Noted that NEODyS has updated its 2007 XK11 risk assessment - see above
Noted that JPL Sentry has updated its 2007 YG1 risk assessment - see above
Noted that NEODyS has posted 2007 YH1 as an impact risk - see above
Noted that NEODyS has posted 2007 YN1 as an impact risk - see above
0228Noted that JPL Sentry has posted 2007 YH1 as an impact risk - see above
0146Noted that JPL Sentry has posted 2007 XB23 as an impact risk - see above