Contents  on 28 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 28 December '20

The MPC's NEO Confirmation Page has 33 listings

When last checked at 2358 UTC today, the Minor Planet Center's Near Earth Object discovery Confirmation Page (NEOCP) had 33 objects listed. Of these, eighteen were "one nighters." So far The Tracking News has counted a total of 41 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 28 December '20

Minor Planet Electronic Circulars

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


MPEC 2020-Y150 - "17:14 UT" - 2020 YW4


MPEC 2020-Y149 - "17:11 UT" - 2020 YV4


MPEC 2020-Y148 - "15:38 UT" - 2020 YU4


MPEC 2020-Y147 - "15:04 UT" - 2020 YT4


MPEC 2020-Y146 - "13:55 UT" - 2020 YS4


<< DOU on 28 December '20 >>  MPEC 2020-Y145 - "12:00 UT" - Daily Orbit Update

Observers  on 28 December '20

Eighteen observers appear in today's MPECs.

CodeObserver / observatory
T05ATLAS Haleakala in Hawaii, 4 in MPEC 2020-Y145 -- 216707, 141079, 8567, 1036
703Catalina Sky Survey (CSS) in Arizona, 19 in MPEC 2020-Y145 -- 2020 YQ3, 2020 XP2, 2003 YM1, 2002 GZ8, 2001 YV3, 89355, 508767, 418849, 417217, 23183, 21088, 152941, 138095, 137805, 10150, 8567, 6053, 5131, 1981
807|Robert Holmes in Illinois via Cerro Tololo Inter-American Obs. (CTIO) in Chile, 3 in MPECs 2020-Y148, 2020-Y149 & 2020-Y150 -- 2020 YW4, 2020 YV4, 2020 YU4
Z99Clixby Obs. in England, 1 in MPEC 2020-Y146 -- 2020 YS4
595Farra d'Isonzo Obs. in Italy, 1 in MPEC 2020-Y146 -- 2020 YS4
J95Great Shefford Obs. in England, 2 in MPECs 2020-Y146 & 2020-Y147 -- 2020 YT4, 2020 YS4
G96Mt. Lemmon Survey (MLS) in Arizona, 29 in MPECs 2020-Y145, 2020-Y146 & 2020-Y147 -- 2020 YT4, 2020 YS4, 2020 YQ1, 2020 YB4, 2020 YA4, 2020 WM3, 2020 WL3, 2020 VM3, 2020 OK5, 2017 XL62, 2009 WD11, 99935, 508774, 508767, 486001, 483547, 418900, 416694, 376848, 361754, 313276, 307493, 174881, 171819, 162186, 154658, 154555, 137099, 1865
644NEAT's Mt. Palomar telescope in southern California, 1 in MPEC 2020-Y145 -- 35396
608NEAT's USAF Haleakala telescope in Hawaii, 1 in MPEC 2020-Y145 -- 35396
Z80Northolt Branch Obs. in England, 1 in MPEC 2020-Y146 -- 2020 YS4
F51Pan-STARRS 1 (PS1) in Hawaii, 9 in MPECs 2020-Y145, 2020-Y147, 2020-Y148, 2020-Y149 & 2020-Y150 -- 2020 YW4, 2020 YV4, 2020 YU4, 2020 YT4, 2020 WM5, 2020 VC7, 2019 BO1, 154330, 137099
619Sabadell Obs. in Spain, 1 in MPEC 2020-Y145 -- 2012 XE133
C95SATINO-1 in France, 1 in MPEC 2020-Y145 -- 32906
204Schiaparelli Obs. in Italy, 1 in MPEC 2020-Y147 -- 2020 YT4
291Spacewatch 1.8m telescope in Arizona, 3 in MPECs 2020-Y148, 2020-Y149 & 2020-Y150 -- 2020 YW4, 2020 YV4, 2020 YU4
I52Steward Obs. Mt. Lemmon Station in Arizona, 13 in MPECs 2020-Y145 & 2020-Y146 -- 2020 YS4, 2020 YQ3, 2020 YK4, 2020 XP2, 2020 WV5, 2020 WL3, 2020 WH2, 2020 WA5, 2020 RU, 2020 PC5, 2019 BO1, 2017 BQ93, 2011 CL50
T12UH/Tholen NEO Follow-Up 2.24m Telescope in Hawaii, 1 in MPEC 2020-Y145 -- 2017 AQ19
L01Visnjan Obs. in Croatia, 2 in MPECs 2020-Y146 & 2020-Y147 -- 2020 YT4, 2020 YS4
For a list of all participating observatories that have Web addresses, see A/CC's Observatory Links page.

Impact Risk Monitoring  on 28 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.
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
2020 YN4NEODyS19002060-21202241.21e-04-5.24-6.22n/aNEODyS: "Based on 28 optical observations (of which 0 are rejected as outliers) from 2020-12-24.436 to 2020-12-27.074."
2020 YC3NEODyS19002096-210621.77e-10-7.27-7.410NEODyS: "Based on 30 optical observations (of which 0 are rejected as outliers) from 2020-12-21.273 to 2020-12-27.273."
2020 YA3NEODyS19002049-2120231.75e-05-5.27-5.35n/aNEODyS: "Based on 34 optical observations (of which 0 are rejected as outliers) from 2020-12-21.357 to 2020-12-27.339."
2020 YL1NEODyS19002038-211623.86e-09-5.36-5.360NEODyS: "Based on 53 optical observations (of which 0 are rejected as outliers) from 2020-12-19.376 to 2020-12-27.265."
2020 YA1NEODyS19002103-211065.43e-06-6.60-6.990NEODyS: "Based on 59 optical observations (of which 0 are rejected as outliers) from 2020-12-17.405 to 2020-12-27.452."
2020 XFNEODyS19002056-21205401.4e-03-3.86-3.95n/aNEODyS: "Based on 100 optical observations (of which 3 are rejected as outliers) from 2020-12-04.328 to 2020-12-27.135."
2011 YC40JPL Sentry19002028-205075.69068e-06-6.79-6.840JPL: Computed at 08:54 April 10th of 2017 Pacific time based on 13 observations spanning 1.0493 days (2011-Dec-29.27153 to 2011-Dec-30.32086). Diameter approximately 0.004 km. from weighted mean H=29.67.
2011 CL50NEODyS1900211218.65e-11-11.80-11.80NEODyS: "Based on 31 optical observations (of which 1 are rejected as outliers) from 2011-02-12.463 to 2020-12-27.326."

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 28 December '20

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

1900Noted that NEODyS has updated its 2011 CL50 risk assessment - see above
Noted that JPL Sentry has updated its 2011 YC40 risk assessment - see above
Noted that NEODyS has updated its 2020 XF risk assessment - see above
Noted that NEODyS has updated its 2020 YA1 risk assessment - see above
Noted that NEODyS has updated its 2020 YA3 risk assessment - see above
Noted that NEODyS has updated its 2020 YC3 risk assessment - see above
Noted that NEODyS has updated its 2020 YL1 risk assessment - see above
Noted that NEODyS has posted 2020 YN4 as an impact risk - see above
1800Grabbed MPEC 2020-Y149 - 2020 YV4 - see above
Grabbed MPEC 2020-Y150 - 2020 YW4 - see above
1700Grabbed MPEC 2020-Y145 - Daily Orbit Update - see above
Grabbed MPEC 2020-Y146 - 2020 YS4 - see above
Grabbed MPEC 2020-Y147 - 2020 YT4 - see above
Grabbed MPEC 2020-Y148 - 2020 YU4 - see above