Contents  on 13 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 13 December '18

Six objects reported inside ten LD

Six transient natural objects are reported to be inside ten lunar distances (LD) of our planet today. Nearest are 2018 XL1, outbound from 2.63 to 3.41 LD, and risk-listed 2018 VO9, inbound from 3.05 to 2.78 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  4.85 to 5.25 LD Nov. 8 - Dec. 25 intruder, NHATS target - DOU
2.42 LD yesterday 2018 XL1 14 m  2.63 to 3.41 LD Dec. 5 - 19 NHATS target
2.62 LD Dec. 15 2018 VO9 14 m  2.78 from 3.05 LD Nov. 29 - Dec. 31 NHATS target, risk
3.92 LD Dec. 2 2018 TG6 12 m  4.86 to 5.03 LD Oct. 30 - Jan. 5 NHATS target
4.1   LD Dec. 9* 2013 VX4 62 m  6.4 to 7.6 LD Dec. 3 - 15 EPU +/- 7.06 days*
5.58 LD today 2018 XJ1 18 m  5.58 LD Dec. 7 - 19 Earth closest at 0559 UTC
* EPU = Earth passage uncertainty

This report was generated at 1851 UTC with follow-up in today's DOU MPEC for outbound risk-listed 2018 WV1 and for six departed objects: 2018 XW, 2018 VL3 (18.95 days added to 15.78-day observing arc), and including four that are risk listed: 2018 XQ2, 2018 XF2, 2018 XA, and intruder 2018 WA3.

Approaching - sorted by 10-LD bubble entry date
Earth passage I D ~Size Distance today  Inside ten LD Notes
7.36 LD Dec. 22 163899 2003 SD220 1.17 km  13.38 from 14.55 LD Dec. 17 - 26 radar/NHATS target
7.3   LD Jan. 9* 2013 YM2 19 m  26.6 from 27.6 LD Jan. 2 - 16 EPU +/- 3.75 days*, NHATS target



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. "LD*" indicates some uncertainty in object passage time and distance. See also current sky chart and object details (alt-details), ephemerides, and today's timeline.

Radar Astrometry  on 13 December '18

Radar observation of one object

The JPL Solar System Dynamics Group Radar Astrometry database has added or updated the following small-body radar observing work:


Data update noted at 2203 UTC when the database was dated 13 Dec.

NEOCP Activity  on 13 December '18

The MPC's NEO Confirmation Page has 60 listings

When last checked at 2358 UTC today, the Minor Planet Center's Near Earth Object discovery Confirmation Page (NEOCP) had 60 objects listed. Of these, 37 were "one nighters." So far The Tracking News has counted a total of 64 listings on the NEOCP today.

New MPECs  on 13 December '18

Minor Planet Electronic Circulars

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


<< DOU on 13 Dec. '18 >>  MPEC 2018-X106 - "13:05 UT" - Daily Orbit Update

Observers  on 13 December '18

A total of 22 observers appear in today's MPEC.

CodeObserver / observatory
251Arecibo in Puerto Rico, 1 in radar -- 46P
T08ATLAS Mauna Loa in Hawaii, 4 in MPEC 2018-X106 -- 2017 BP5, 2014 JU54, 2002 XC91, 523811
160Castelmartini Obs. in Italy, 13 in MPEC 2018-X106 -- 2018 XA, 2018 TS, 2018 GX4, 2014 XR6, 2010 GT7, 2003 NW1, 2001 VC2, 523604, 518735, 457260, 424482, 345705, 154656
807|Robert Holmes in Illinois via Cerro Tololo Inter-American Obs. (CTIO) in Chile, 11 in MPEC 2018-X106 -- 2018 XZ1, 2018 XB2, 2018 WY2, 2018 WW1, 2018 VL3, 2018 VK10, 2018 VH3, 2018 RX, 2018 RM2, 2018 PJ22, 2018 GA5
L29Drebach-South Obs., 4 in MPEC 2018-X106 -- 2018 VN3, 2018 KV, 2013 BW76, 2002 XC91
L28ISON Castelgrande Obs., 1 in MPEC 2018-X106 -- 2003 NW1
W85LCO Cerro Tololo A in Chile, 1 in MPEC 2018-X106 -- 2018 WV1
L52MASTER Tavrida, 6 in MPEC 2018-X106 -- 333888, 159399, 137158, 9856, 6053, 5660
K95MASTER-II Sutherland in South Africa, 2 in MPEC 2018-X106 -- 523587, 443923
B67Mirasteilas Obs. in Switzerland, 1 in MPEC 2018-X106 -- 3200
G96Mt. Lemmon Survey (MLS) in Arizona, 3 in MPEC 2018-X106 -- 2018 XN, 2018 XF2, 523824
644NEAT's Mt. Palomar telescope in southern California, 2 in MPEC 2018-X106 -- 2018 KM2, 2001 WO15
Z80Northolt Branch Obs. in England, 1 in MPEC 2018-X106 -- 2009 SV17
F51Pan-STARRS 1 (PS1) in Hawaii, 19 in MPEC 2018-X106 -- 2018 XO2, 2018 XH, 2018 WN2, 2015 WY1, 2013 BT18, 2011 AA37, 2010 XC11, 2006 WR127, 2005 YY36, 2003 WY87, 2002 GA, 2001 WO15, 457212, 424482, 329390, 173664, 171819, 138852, 2212
C95SATINO-1 in France, 1 in MPEC 2018-X106 -- 2003 NW1
204Schiaparelli Obs. in Italy, 1 in MPEC 2018-X106 -- 2018 XE2
691Spacewatch 0.9m telescope in Arizona, 10 in MPEC 2018-X106 -- 2018 XN, 2018 VN5, 2018 UY, 2018 TO6, 2018 LB1, 2015 YE21, 2015 CZ, 2014 AA33, 2011 WM46, 2000 AA6
291Spacewatch 1.8m telescope in Arizona, 4 in MPEC 2018-X106 -- 2018 XQ2, 2018 VK1, 2018 UJ, 2014 XX31
I52Steward Obs. Mt. Lemmon Station in Arizona, 22 in MPEC 2018-X106 -- 2018 XZ1, 2018 XW, 2018 XH, 2018 XE2, 2018 XD2, 2018 XD, 2018 XB2, 2018 WX2, 2018 WV2, 2018 WU1, 2018 WO2, 2018 WH2, 2018 WC1, 2018 WA2, 2018 VY7, 2018 VY5, 2018 VV1, 2018 VM3, 2018 VC5, 2018 UZ, 2018 SA3, 2018 PJ22
Z52The Studios Obs., 1 in MPEC 2018-X106 -- 16816
T12UH/Tholen NEO Follow-Up 2.24m Telescope in Hawaii, 1 in MPEC 2018-X106 -- 2018 WA3
C51WISE in Earth polar orbit, 3 in MPEC 2018-X106 -- 523824, 17274, 4596
For a list of all participating observatories that have Web addresses, see A/CC's Observatory Links page.

Impact Risk Monitoring  on 13 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 XQ2JPL Sentry16402053-21181170.0008379188988-4.78-4.980JPL: Computed at 08:24 today Pacific time based on 25 observations spanning 3.1166 days (2018-Dec-10.2423 to 2018-Dec-13.35887). Diameter approximately 0.008 km. from weighted mean H=28.20.
2018 XF2JPL Sentry16402053-210421.5146e-07-7.50-7.720JPL: Computed at 08:08 today Pacific time based on 59 observations spanning 3.0547 days (2018-Dec-10.26869 to 2018-Dec-13.32335). Diameter approximately 0.019 km. from weighted mean H=26.23.
2018 XAJPL Sentry16402099-209924.243e-08-6.85-7.020JPL: Computed at 07:57 today Pacific time based on 116 observations spanning 10.935 days (2018-Dec-01.34686 to 2018-Dec-12.28162). Diameter approximately 0.064 km. from weighted mean H=23.62.
2018 WA3JPL Sentry16402055-206022.61619e-06-6.67-6.680JPL: Computed at 08:14 today Pacific time based on 28 observations spanning 9.1706 days (2018-Nov-29.26148 to 2018-Dec-08.432077). Diameter approximately 0.009 km. from weighted mean H=27.83.

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 13 December '18

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

2203Noted Radar Astrometry database update - see above
1851Generated Traffic Report
1640Noted that JPL Sentry has updated its 2018 WA3 risk assessment - see above
Noted that JPL Sentry has updated its 2018 XA risk assessment - see above
Noted that JPL Sentry has updated its 2018 XF2 risk assessment - see above
Noted that JPL Sentry has updated its 2018 XQ2 risk assessment - see above
Grabbed MPEC 2018-X106 - Daily Orbit Update - see above