Contents  on 29 December '20

CHANGES COMING:  The Asteroid/Comet Connection Web site will soon focus completely on Earth's Busy Neighborhood reporting. Sometime on or soon after Sunday, December 27th, much of the site will be retired.* The Tracking News will be discontinued and taken down entirely** along with its supporting timeline pages, the archives of its predecessor online publication, Major News About Minor Objects, and our even longer running Consolidated Risk Tables feature. Remaining will be Earth's Busy Neighborhood along with its sky chart, ephemerides, and some supporting pages (e.g. Observatory Links). We do plan to make the Web site easier to use, more interesting as regards close-passing asteroids, and more glitch-free while needing much, much less manual attention here than the current site. -- Webmaster

  *There will be some chaos when we take down the old site and put up the new. Please check back.
**You can still find the old files at the Internet Archive.

Asteroid/Comet Connection (A/CC) Resources:

The latest A/CC news is available via framed access, RSS news feed RSS news feed, or redirection.

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. To keep track of what's new each day, watch the Chronology section.

NEOCP Activity  on 29 December '20

The MPC's NEO Confirmation Page has 31 listings

When last checked at 2358 UTC today, the Minor Planet Center's Near Earth Object discovery Confirmation Page (NEOCP) had 31 objects listed. Of these, sixteen were "one nighters." So far The Tracking News has counted a total of 34 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 29 December '20

Minor Planet Electronic Circulars

As of last check at 2358 UTC, there have been four MPECs posted today from the International Astronomical Union's Minor Planet Center in Cambridge, Massachusetts.

MPEC 2020-Y154 - "20:15 UT" - 2020 YZ4

MPEC 2020-Y153 - "15:08 UT" - 2020 YY4

<< DOU on 29 December '20 >>  MPEC 2020-Y152 - "12:01 UT" - Daily Orbit Update

MPEC 2020-Y151 - "04:20 UT" - 2020 RO9

Observers  on 29 December '20

A total of 21 observers appear in today's MPECs.

CodeObserver / observatory
T05ATLAS Haleakala in Hawaii, 3 in MPEC 2020-Y152 -- 162186, 137805, 6053
T08ATLAS Mauna Loa in Hawaii, 17 in MPEC 2020-Y152 -- 1999 VX15, 87684, 86450, 85709, 85275, 65717, 35107, 186822, 7977, 5879, 4953, 4055, 1980, 1943, 1685, 1036, 433
726Brainerd Obs. in Minnesota, 1 in MPEC 2020-Y152 -- 163902
703Catalina Sky Survey in Arizona, 1 in MPEC 2020-Y152 -- 2017 SE19
807|Robert Holmes in Illinois via Cerro Tololo Inter-American Obs. (CTIO) in Chile, 31 in MPECs 2020-Y152 & 2020-Y153 -- 2020 YZ2, 2020 YY4, 2020 YS, 2020 YL2, 2020 YJ1, 2020 YJ, 2020 YG2, 2020 YE, 2020 YC, 2020 XV6, 2020 XV4, 2020 XV2, 2020 XT2, 2020 XR6, 2020 XK3, 2020 XH4, 2020 XG4, 2020 XE5, 2020 XC7, 2020 XC5, 2020 XA7, 2020 WT5, 2020 WQ1, 2020 UM8, 2020 UL1, 2020 TG3, 2020 TC7, 2020 TB12, 2020 RZ5, 2020 RO6, 2020 KU3
595Farra d'Isonzo Obs. in Italy, 1 in MPEC 2020-Y152 -- 2020 WA5
E89Geyserland Obs. in New Zealand, 2 in MPEC 2020-Y152 -- 65717, 1036
G96Mt. Lemmon Survey (MLS) in Arizona, 4 in MPECs 2020-Y151, 2020-Y152 & 2020-Y154 -- 2020 YZ4, 2020 YW4, 2020 YV4, 2020 RO9
K74Muensterschwarzach Obs. in Germany, 1 in MPEC 2020-Y152 -- 2003 YJ
C51NEOWISE in Earth polar orbit, 1 in MPEC 2020-Y152 -- 275611
Z80Northolt Branch Obs. in England, 1 in MPEC 2020-Y152 -- 2012 XE133
F51Pan-STARRS 1 (PS1) in Hawaii, 4 in MPECs 2020-Y152 & 2020-Y153 -- 2020 YY4, 2020 RO9, 68359, 414586
F52Pan-STARRS 2 (PS2) in Hawaii, 2 in MPEC 2020-Y152 -- 154330, 10115
C95SATINO-1 in France, 1 in MPEC 2020-Y152 -- 34613
204Schiaparelli Obs. in Italy, 15 in MPEC 2020-Y152 -- 2020 YU3, 2020 YP3, 2020 YM4, 2020 YK4, 2020 YG3, 2020 YC4, 2020 YA1, 2020 XP2, 2020 XN1, 2020 TG4, 2020 QS5, 2012 XE133, 2010 XX58, 482505, 36284
Q21Southern Utsunomiya in Japan, 1 in MPEC 2020-Y152 -- 99942
291Spacewatch 1.8m telescope in Arizona, 1 in MPEC 2020-Y153 -- 2020 YY4
I52Steward Obs. Mt. Lemmon Station in Arizona, 1 in MPEC 2020-Y154 -- 2020 YZ4
A16Tentlingen Obs. in Switzerland, 3 in MPEC 2020-Y152 -- 2020 TG4, 138095, 6053
T12UH/Tholen NEO Follow-Up 2.24m Telescope in Hawaii, 1 in MPEC 2020-Y152 -- 2002 EW8
L01Visnjan Obs. in Croatia, 1 in MPEC 2020-Y154 -- 2020 YZ4
For a list of all participating observatories that have Web addresses, see A/CC's Observatory Links page.

Impact Risk Monitoring  on 29 December '20

Summary Risk Table for Risk Assessments Updated Today   (last checks: NEODyS at 2358 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 and NEODyS listings is 100 years, and both post impact solutions beyond that for some special objects.
For the latest official risk assessments, and for explanations of the terminology, see the NASA/JPL Sentry and NEODyS CLOMON2 risk pages.





Notes for Today's Latest Risk Assessments
2020 YG2NEODyS20002097-210935.71e-07-6.34-6.450NEODyS: "Based on 39 optical observations (of which 0 are rejected as outliers) from 2020-12-20.194 to 2020-12-25.168."
JPL Sentry17002097-210923.78103e-07-6.52-6.530JPL: Computed at 05:44 today Pacific time based on 39 observations spanning 4.9748 days (2020-Dec-20.19277 to 2020-Dec-25.1676). Diameter approximately 0.040 km. from weighted mean H=24.64.
2020 YA1NEODyS20002103-211021.12e-06-7.29-7.360NEODyS: "Based on 62 optical observations (of which 0 are rejected as outliers) from 2020-12-17.405 to 2020-12-27.452."
JPL Sentry17002103-211343.0198e-06-6.85-7.020JPL: Computed at 06:13 today Pacific time based on 62 observations spanning 10.047 days (2020-Dec-17.404234 to 2020-Dec-27.451476). Diameter approximately 0.015 km. from weighted mean H=26.75.
2020 XV6NEODyS20002099-210559.45e-07-4.59-4.930NEODyS: "Based on 100 optical observations (of which 1 are rejected as outliers) from 2020-12-15.121 to 2020-12-22.170."
JPL Sentry17002099-210236.118e-07-4.76-5.060JPL: Computed at 05:51 today Pacific time based on 100 observations spanning 7.0493 days (2020-Dec-15.120177 to 2020-Dec-22.169524). Diameter approximately 0.097 km. from weighted mean H=22.70.
2020 VVJPL Sentry20002044-21201510.002266053662-3.88-4.360JPL: Computed at 11:17 today Pacific time based on 79 observations spanning 61.112 days (2020-Oct-17.214515 to 2020-Dec-17.326949). Diameter approximately 0.012 km. from weighted mean H=27.27.
2011 CL50JPL Sentry1807R E M O V E DJPL: Risk listing removed at 1642 UTC Dec. 27th
2008 EA9JPL Sentry17002068-210662.30722e-05-6.26-6.660JPL: Computed at 13:14 April 7th of 2017 Pacific time based on 56 observations spanning 27.860 days (2008-Mar-06.40551 to 2008-Apr-03.26595). Diameter approximately 0.010 km. from weighted mean H=27.73.

Legend: VI# = VI count, Prob Cum = cumulative probability, PS Cum/Max = cumulative/maximum Palermo Scale, TS = Torino Scale (next 100 years)

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 29 December '20

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

2105Grabbed MPEC 2020-Y154 - 2020 YZ4 - see above
2000Noted that JPL Sentry has updated its 2020 VV risk assessment - see above
Noted that NEODyS has updated its 2020 XV6 risk assessment - see above
Noted that NEODyS has updated its 2020 YA1 risk assessment - see above
Noted that NEODyS has updated its 2020 YG2 risk assessment - see above
1807Noted that JPL Sentry has removed 2011 CL50 as an impact risk - see above
1700Noted that JPL Sentry has updated its 2008 EA9 risk assessment - see above
Noted that JPL Sentry has updated its 2020 XV6 risk assessment - see above
Noted that JPL Sentry has updated its 2020 YA1 risk assessment - see above
Noted that JPL Sentry has updated its 2020 YG2 risk assessment - see above
Grabbed MPEC 2020-Y152 - Daily Orbit Update - see above
Grabbed MPEC 2020-Y153 - 2020 YY4 - see above
0600Grabbed MPEC 2020-Y151 - 2020 RO9 - see above