Contents  on 20 December '18

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.

Traffic Report  on 20 December '18

Ten objects reported inside ten LD

There are ten transient natural objects reported within ten lunar distances (LD) of Earth today. Closest is 2018 XC4, which enters our planet's sphere of gravitational influence, sliding in from 3.27 to 1.96 LD.

Neighborhood Traffic - sorted by Earth passage distance, grouped by 1.0, 2.41, 5.0 & 10.0 LD boundaries
Earth passage I D ~Size Distance today  Inside ten LD Notes
0.09 LD Dec. 2 2018 WV1 3 m  7.69 to 8.10 LD Nov. 8 - Dec. 25 intruder, NHATS target
1.25 LD Dec. 10 2018 XX3 4 m  9.47 to 10.49 LD Nov. 30 - today NHATS target, exits ten LD, risk
1.60 LD tomorrow 2018 XC4 19 m  1.96 from 3.27 LD Dec. 15 - 27 NHATS target, enters Earth SOI
2.62 LD Dec. 15 2018 VO9 14 m  3.88 to 4.36 LD Nov. 29 - Dec. 31 NHATS target, risk
2.72 LD Dec. 15 2018 XG4 10 m  9.03 to 10.70 LD Dec. 9 - 20 exits ten LD
2.76 LD Dec. 16 2018 XS4 31 m  7.59 to 9.40 LD Dec. 11 - 21 DOU
2.96 LD Dec. 24 2018 XN5 25 m  6.12 from 7.40 LD Dec. 18 - 31 NHATS target, risk
3.92 LD Dec. 2 2018 TG6 12 m  6.23 to 6.45 LD Oct. 30 - Jan. 5 NHATS target
5.32 LD Dec. 17 2018 XR4 15 m  7.47 to 9.45 LD Dec. 14 - 21 risk
7.36 LD Dec. 22 163899 2003 SD220 1.17 km  7.50 from 7.89 LD Dec. 17 - 26 radar/NHATS target

This report was generated at 1812 UTC with follow-up in today's DOU MPEC for inbound 2018 XS4 and departed objects 2018 XB5 and risk-listed intruder 2018 WE1.

Approaching - sorted by 10-LD bubble entry date
Earth passage I D ~Size Distance today  Inside ten LD Notes
5.3   LD Dec. 26* 2018 XE4 17 m  13.4 from 15.4 LD Dec. 22 - 30 EPU +/- 3.33 hours*
7.8   LD Jan. 6* 2018 XO4 29 m  16.7 from 17.5 LD Dec. 30 - Jan. 13 EPU +/- 3.18 hours*, NHATS target
7.3   LD Jan. 9* 2013 YM2 19 m  20.2 from 21.1 LD Jan. 2 - 16 EPU +/- 3.75 days*, NHATS target
* EPU = Earth passage uncertainty



Notes: Ten times the distance to the Moon (ten LD) has no astronomical importance but is a useful boundary for reporting about transient natural objects that approach our planet's gravitational sphere of influence (SOI), which has a radius of about 2.41 LD from Earth's center. This puts a focus on some of the most important and very best NEO observation work, representative of the much larger NEO discovery and tracking effort. Object temporal distances are derived by A/CC from JPL Horizons data. See also current sky chart and object details (alt-details), ephemerides, and today's timeline.

NEOCP Activity  on 20 December '18

The MPC's NEO Confirmation Page has 38 listings

When last checked at 2358 UTC today, the Minor Planet Center's Near Earth Object discovery Confirmation Page (NEOCP) had 38 objects listed. Of these, 26 were "one nighters." So far The Tracking News has counted a total of 53 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 20 December '18

Minor Planet Electronic Circulars

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


MPEC 2018-Y53 - "21:25 UT" - Comet P/2018 P3 (Panstarrs)


MPEC 2018-Y52 - "18:04 UT" - Comet C/2018 Y1 (Iwamoto)


MPEC 2018-Y51 - "17:06 UT" - 2018 YW


MPEC 2018-Y50 - "17:03 UT" - 2018 YV


MPEC 2018-Y49 - "17:00 UT" - 2018 YU


MPEC 2018-Y48 - "16:56 UT" - 2018 YT


MPEC 2018-Y47 - "16:53 UT" - 2018 YS


MPEC 2018-Y46 - "16:50 UT" - 2018 XU6


MPEC 2018-Y45 - "16:46 UT" - 2018 XT6


<< DOU on 20 Dec. '18 >>  MPEC 2018-Y44 - "13:06 UT" - Daily Orbit Update


MPEC 2018-Y43 - "04:01 UT" - 2002 AA2

Observers  on 20 December '18

A total of 40 observers appear in today's MPECs.

CodeObserver / observatory
L2729PREMOTE Obs., 1 in MPEC 2018-Y44 -- 3200
349Ageo Obs. in Japan, 2 in MPECs 2018-Y52 & 2018-Y53 -- C/2018 Y1, P/2018 P3
H21Astronomical Research Obs. Westfield in Illinois, 9 in MPECs 2018-Y44, 2018-Y48, 2018-Y50 & 2018-Y51 -- 2018 YW, 2018 YV, 2018 YT, 2018 XW4, 2018 VJ5, 2018 UQ2, 2014 AY28, 2012 BN11, 2011 AW55
T05ATLAS Haleakala in Hawaii, 2 in MPECs 2018-Y44 & 2018-Y53 -- P/2018 P3, 2010 GT7
T08ATLAS Mauna Loa in Hawaii, 2 in MPECs 2018-Y44 & 2018-Y53 -- P/2018 P3, 418849
215Buchloe Obs. in Germany, 1 in MPEC 2018-Y53 -- P/2018 P3
160Castelmartini Obs. in Italy, 1 in MPEC 2018-Y44 -- 2003 NW1
703Catalina Sky Survey in Arizona, 1 in MPEC 2018-Y53 -- P/2018 P3
V06Catalina Sky Survey Kuiper Telescope in Arizona, 1 in MPEC 2018-Y45 -- 2018 XT6
807|Robert Holmes in Illinois via Cerro Tololo Inter-American Obs. (CTIO) in Chile, 6 in MPECs 2018-Y44 & 2018-Y48 -- 2018 YT, 2018 WY2, 2018 VK1, 2018 VE5, 2018 RM2, 2018 PM9
822Cordoba Obs. in Argentina, 1 in MPEC 2018-Y44 -- 418849
H06iTelescope Obs. Mayhill in New Mexico, 1 in MPEC 2018-Y52 -- C/2018 Y1
H06%Ernesto Guido in Italy via iTelescope Obs. Mayhill in New Mexico, 1 in MPEC 2018-Y52 -- C/2018 Y1
H06|Hidetaka Sato in Japan via iTelescope Obs. Mayhill in New Mexico, 1 in MPEC 2018-Y52 -- C/2018 Y1
585Kiev Comet Station in Ukraine, 1 in MPEC 2018-Y53 -- P/2018 P3
T03LCO Haleakala Clamshell#3 in Hawaii, 1 in MPEC 2018-Y52 -- C/2018 Y1
L52MASTER Tavrida, 5 in MPEC 2018-Y44 -- 508796, 25916, 19764, 137158, 9856
D54MASTER-II Blagoveshchensk in Russia, 1 in MPEC 2018-Y44 -- 454177
K95MASTER-II Sutherland in South Africa, 1 in MPEC 2018-Y44 -- 7350
C94MASTER-II Tunka in Russia, 1 in MPEC 2018-Y44 -- 18736
568^R. Wainscoat on Mauna Kea in Hawaii, 4 in MPECs 2018-Y45, 2018-Y46, 2018-Y48 & 2018-Y49 -- 2018 YU, 2018 YT, 2018 XU6, 2018 XT6
G96Mt. Lemmon Survey (MLS) in Arizona, 2 in MPECs 2018-Y43 & 2018-Y53 -- P/2018 P3, 2002 AA2
Z80Northolt Branch Obs. in England, 1 in MPEC 2018-Y44 -- 2012 MS4
C23Olmen Obs. in Belgium, 1 in MPEC 2018-Y44 -- 2003 NW1
I41Palomar Transient Factory (PTF) in southern California, 14 in MPECs 2018-Y44 & 2018-Y47 -- 2018 YS, 2018 VH2, 2011 XE1, 86324, 523805, 523610, 363067, 357022, 308127, 250577, 139622, 5324, 2212, 2100
F51Pan-STARRS 1 (PS1) in Hawaii, 7 in MPECs 2018-Y43, 2018-Y45, 2018-Y46, 2018-Y48, 2018-Y49, 2018-Y50 & 2018-Y51 -- 2018 YW, 2018 YV, 2018 YU, 2018 YT, 2018 XU6, 2018 XT6, 2002 AA2
F52Pan-STARRS 2 in Hawaii, 1 in MPEC 2018-Y45 -- 2018 XT6
D29Purple Mtn. Obs. Xuyi Station in China, 17 in MPECs 2018-Y44 & 2018-Y53 -- 2018 UY, 2018 TN6, 2018 RK7, P/2018 P3, 2018 KE3, 2014 XR6, 2011 KN9, 90075, 443923, 442742, 349507, 30825, 25143, 224926, 16834, 3691, 3288
619Sabadell Obs. in Spain, 1 in MPEC 2018-Y44 -- 2018 XS4
104San Marcello Pistoiese Obs. in Italy, 1 in MPEC 2018-Y47 -- 2018 YS
C95SATINO-1 in France, 2 in MPECs 2018-Y44 & 2018-Y47 -- 2018 YS, 2002 XQ90
Q11Shinshiro Obs., 1 in MPEC 2018-Y53 -- P/2018 P3
G403Tony Evans in Portugal via Slooh.com Canary Islands Obs. in the Canary Islands, 1 in MPEC 2018-Y44 -- 2018 XS4
G409B. Lutkenhoner in Germany via Slooh.com Canary Islands Obs. in the Canary Islands, 1 in MPEC 2018-Y53 -- P/2018 P3
W88#program code "#" (12) via Slooh.com Chile Obs. in Chile, 1 in MPEC 2018-Y52 -- C/2018 Y1
691Spacewatch 0.9m telescope in Arizona, 8 in MPECs 2018-Y44, 2018-Y46 & 2018-Y49 -- 2018 YU, 2018 XU6, 2018 XD5, 2018 UY, 2018 TY2, 2018 TC3, 2016 CA136, 2013 BW76
291Spacewatch 1.8m telescope in Arizona, 3 in MPECs 2018-Y44 & 2018-Y45 -- 2018 XT6, 2018 WE1, 2018 VT8
I52Steward Obs. Mt. Lemmon Station in Arizona, 32 in MPECs 2018-Y43, 2018-Y44, 2018-Y49, 2018-Y50 & 2018-Y51 -- 2018 YW, 2018 YV, 2018 YU, 2018 YL, 2018 YJ, 2018 YB, 2018 XZ1, 2018 XS4, 2018 XQ4, 2018 XP3, 2018 XK5, 2018 XH, 2018 XD5, 2018 XB5, 2018 XA5, 2018 WC1, 2018 WA2, 2018 VY7, 2018 VV1, 2018 VT8, 2018 VM3, 2018 VE4, 2018 VC5, 2018 VA10, 2018 UZ, 2018 UY, 2018 TY2, 2018 TX4, 2018 TL2, 2018 TC3, 2018 RP8, 2002 AA2
872Tokushima Obs. in Japan, 1 in MPEC 2018-Y52 -- C/2018 Y1
T12UH/Tholen NEO Follow-Up 2.24m Telescope in Hawaii, 1 in MPEC 2018-Y44 -- 2018 WE1
L01Visnjan Obs., 3 in MPECs 2018-Y46, 2018-Y47 & 2018-Y50 -- 2018 YV, 2018 YS, 2018 XU6
C51WISE in Earth polar orbit, 4 in MPECs 2018-Y44 & 2018-Y53 -- 2018 VQ3, P/2018 P3, 523806, 153219
367Yatsuka Obs. in Japan, 1 in MPEC 2018-Y53 -- P/2018 P3
For a list of all participating observatories that have Web addresses, see A/CC's Observatory Links page.

Impact Risk Monitoring  on 20 December '18

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
2018 YJJPL Sentry17032029-2118654.962735e-07-3.16-4.100JPL: Computed at 08:09 today Pacific time based on 23 observations spanning 3.9830 days (2018-Dec-16.5351 to 2018-Dec-20.5181). Diameter approximately 0.640 km. from weighted mean H=18.62.
NEODyS17032024-21181064.52e-07-3.23-4.1-NEODyS: "Based on 23 optical observations (of which 0 are rejected as outliers) from 2018-12-16.536 to 2018-12-20.519."
2018 WE1JPL Sentry17032071-207422.2188e-09-9.18-9.420JPL: Computed at 08:00 today Pacific time based on 81 observations spanning 17.896 days (2018-Nov-26.46885 to 2018-Dec-14.36487). Diameter approximately 0.021 km. from weighted mean H=26.02.
NEODyS17032063-209552.91e-07-7.07-7.240NEODyS: "Based on 83 optical observations (of which 2 are rejected as outliers) from 2018-11-26.470 to 2018-12-14.366."

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 20 December '18

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

2135Grabbed MPEC 2018-Y53 - Comet P/2018 P3 (Panstarrs) - see above
1830Grabbed MPEC 2018-Y52 - Comet C/2018 Y1 (Iwamoto) - see above
1812Generated Traffic Report
1737Grabbed MPEC 2018-Y50 - 2018 YV - see above
Grabbed MPEC 2018-Y51 - 2018 YW - see above
1703Noted that JPL Sentry has updated its 2018 WE1 risk assessment - see above
Noted that NEODyS has updated its 2018 WE1 risk assessment - see above
Noted that JPL Sentry has updated its 2018 YJ risk assessment - see above
Noted that NEODyS has updated its 2018 YJ risk assessment - see above
Grabbed MPEC 2018-Y45 - 2018 XT6 - see above
Grabbed MPEC 2018-Y46 - 2018 XU6 - see above
Grabbed MPEC 2018-Y47 - 2018 YS - see above
Grabbed MPEC 2018-Y48 - 2018 YT - see above
Grabbed MPEC 2018-Y49 - 2018 YU - see above
1630Grabbed MPEC 2018-Y44 - Daily Orbit Update - see above
0612Grabbed MPEC 2018-Y43 - 2002 AA2 - see above