Contents  on 17 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 17 December '18

Twelve objects reported inside ten LD

Twelve Solar-System small bodies are reported inside ten lunar distances (LD) of our planet today. The two closest are risk-listed 2018 VO9, outbound from 2.79 to 3.07 LD, and 2018 XS4, headed away from 3.06 to 4.25 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  6.47 to 6.87 LD Nov. 8 - Dec. 25 intruder, NHATS target
1.25 LD Dec. 10 2018 XX3 4 m  6.44 to 7.44 LD Nov. 30 - Dec. 20 NHATS target, risk
1.6   LD Dec. 21* 2018 XC4 19 m  6.5 from 8.2 LD Dec. 15 - 27 EPU +/- 6 mins.*, NHATS target - DOU
2.42 LD Dec. 12 2018 XL1 14 m  6.97 to 8.27 LD Dec. 5 - 19 NHATS target
2.62 LD Dec. 15 2018 VO9 14 m  2.79 to 3.07 LD Nov. 29 - Dec. 31 NHATS target, risk
2.72 LD Dec. 15 2018 XG4 11 m  4.34 to 5.80 LD Dec. 9 - 20
2.76 LD yesterday 2018 XS4 30 m  3.06 to 4.25 LD Dec. 11 - 21
3.49 LD Dec. 11 2013 VX4 62 m  8.67 to 10.04 LD Dec. 5 - 17 exits ten LD
3.92 LD Dec. 2 2018 TG6 12 m  5.60 to 5.80 LD Oct. 30 - Jan. 5 NHATS target
5.32 LD today 2018 XR4 15 m  5.32 LD Dec. 14 - 21 Earth closest at 2258 UTC, risk
5.58 LD Dec. 13 2018 XJ1 18 m  7.71 to 8.74 LD Dec. 7 - 19
7.36 LD Dec. 22 163899 2003 SD220 1.17 km  9.28 from 10.18 LD today - Dec. 26 radar/NHATS target, enters ten LD - radar
* EPU = Earth passage uncertainty

This report was generated at 1940 UTC with the discovery of approaching risk-listed 2018 XN5 (MPEC) and with first follow-up in today's DOU MPEC for inbound 2018 XC4 and departed 2018 XB5. We also note radar observation posted yesterday of behemoth 163899 2003 SD220, which today enters our ten-LD traffic reporting space.

Approaching - sorted by 10-LD bubble entry date
Earth passage I D ~Size Distance today  Inside ten LD Notes
3.0   LD Dec. 24* 2018 XN5 25 m  10.1 from 11.4 LD tomorrow - Dec. 31 NEW, EPU +/- 52 mins.*, risk - MPEC
5.3   LD Dec. 26* 2018 XE4 17 m  19.4 from 21.5 LD Dec. 22 - 30 EPU +/- 3.33 hours*
7.8   LD Jan. 6* 2018 XO4 29 m  18.9 from 19.7 LD Dec. 30 - Jan. 13 EPU +/- 3.18 hours*, NHATS target
7.3   LD Jan. 9* 2013 YM2 19 m  23.0 from 23.9 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. See also current sky chart and object details (alt-details), ephemerides, and today's timeline.

NEOCP Activity  on 17 December '18

The MPC's NEO Confirmation Page has 65 listings

When last checked at 2358 UTC today, the Minor Planet Center's Near Earth Object discovery Confirmation Page (NEOCP) had 65 objects listed. Of these, 36 were "one nighters." So far The Tracking News has counted a total of 86 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 17 December '18

Minor Planet Electronic Circulars

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


MPEC 2018-Y24 - "20:08 UT" - Comet C/2018 X3 (Panstarrs)


MPEC 2018-Y23 - "15:27 UT" - 2018 XE5


MPEC 2018-Y22 - "15:23 UT" - 2018 XN5


MPEC 2018-Y21 - "15:19 UT" - 2018 XM5


MPEC 2018-Y20 - "15:14 UT" - 2018 XL5


MPEC 2018-Y19 - "15:06 UT" - 2018 XK5


MPEC 2018-Y18 - "15:01 UT" - 2018 XJ5


MPEC 2018-Y17 - "14:54 UT" - 2018 XH5


MPEC 2018-Y16 - "14:49 UT" - 2018 XG5


MPEC 2018-Y15 - "14:45 UT" - 2018 XF5


MPEC 2018-Y14 - "14:12 UT" - 2018 VG18


<< DOU on 17 Dec. '18 >>  MPEC 2018-Y13 - "13:05 UT" - Daily Orbit Update

Observers  on 17 December '18

A total of 20 observers appear in today's MPECs.

CodeObserver / observatory
T05ATLAS Haleakala in Hawaii, 2 in MPECs 2018-Y18 & 2018-Y19 -- 2018 XK5, 2018 XJ5
T08ATLAS Mauna Loa in Hawaii, 6 in MPEC 2018-Y13 -- 2018 XZ2, 2018 XC4, 2018 XB5, 2015 YU7, 523811, 2340
V06Catalina Sky Survey Kuiper Telescope (CSS-Kuiper) in Arizona, 2 in MPECs 2018-Y20 & 2018-Y23 -- 2018 XL5, 2018 XE5
106Crni Vrh Obs. in Slovenia, 1 in MPEC 2018-Y24 -- C/2018 X3
734Farpoint Obs. in Kansas, 1 in MPEC 2018-Y21 -- 2018 XM5
595Farra d'Isonzo Obs. in Italy, 1 in MPEC 2018-Y24 -- C/2018 X3
P93JAXA Space Tracking & Communications Center in Japan, 1 in MPEC 2018-Y21 -- 2018 XM5
304Las Campanas Obs. in Chile, 1 in MPEC 2018-Y14 -- 2018 VG18
H01Magdalena Ridge Obs. (MRO) in New Mexico, 2 in MPECs 2018-Y21 & 2018-Y24 -- 2018 XM5, C/2018 X3
5685Scott Sheppard on Mauna Kea in Hawaii, 1 in MPEC 2018-Y14 -- 2018 VG18
568^R. Wainscoat on Mauna Kea in Hawaii, 6 in MPECs 2018-Y15, 2018-Y17, 2018-Y19, 2018-Y22, 2018-Y23 & 2018-Y24 -- 2018 XN5, 2018 XK5, 2018 XH5, 2018 XF5, 2018 XE5, C/2018 X3
G96Mt. Lemmon Survey (MLS) in Arizona, 2 in MPECs 2018-Y16 & 2018-Y21 -- 2018 XM5, 2018 XG5
F51Pan-STARRS 1 (PS1) in Hawaii, 18 in MPECs 2018-Y13, 2018-Y15, 2018-Y16, 2018-Y17, 2018-Y18, 2018-Y19, 2018-Y20, 2018-Y22, 2018-Y23 & 2018-Y24 -- 2018 XN5, 2018 XL5, 2018 XK5, 2018 XJ5, 2018 XH5, 2018 XG5, 2018 XF5, 2018 XE5, C/2018 X3, 2018 WR1, 2018 VN3, 2018 VB9, 2018 SX2, 2014 JU54, 2011 OL5, 333521, 140928, 138175
F52Pan-STARRS 2 in Hawaii, 1 in MPEC 2018-Y24 -- C/2018 X3
D29Purple Mtn. Obs. Xuyi Station in China, 1 in MPEC 2018-Y13 -- 459458
H36Sandlot Obs. in Kansas, 1 in MPEC 2018-Y21 -- 2018 XM5
204Schiaparelli Obs. in Italy, 2 in MPECs 2018-Y21 & 2018-Y24 -- 2018 XM5, C/2018 X3
691Spacewatch 0.9m telescope in Arizona, 4 in MPECs 2018-Y15, 2018-Y16, 2018-Y20 & 2018-Y24 -- 2018 XL5, 2018 XG5, 2018 XF5, C/2018 X3
291Spacewatch 1.8m telescope in Arizona, 1 in MPEC 2018-Y17 -- 2018 XH5
I52Steward Obs. Mt. Lemmon Station in Arizona, 4 in MPECs 2018-Y16, 2018-Y18, 2018-Y19 & 2018-Y21 -- 2018 XM5, 2018 XK5, 2018 XJ5, 2018 XG5
L01Visnjan Obs., 6 in MPECs 2018-Y16, 2018-Y18, 2018-Y20, 2018-Y21, 2018-Y22 & 2018-Y24 -- 2018 XN5, 2018 XM5, 2018 XL5, 2018 XJ5, 2018 XG5, C/2018 X3
For a list of all participating observatories that have Web addresses, see A/CC's Observatory Links page.

Impact Risk Monitoring  on 17 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 XN5JPL Sentry17302065-2115141.47660679e-05-5.54-6.020JPL: Computed at 08:31 today Pacific time based on 12 observations spanning 1.9116 days (2018-Dec-15.30928 to 2018-Dec-17.22092). Diameter approximately 0.025 km. from weighted mean H=25.69.
2018 XG5JPL Sentry17302030-2116331.0870907e-06-3.62-3.970JPL: Computed at 07:58 today Pacific time based on 20 observations spanning 2.9144 days (2018-Dec-13.39431 to 2018-Dec-16.30868). Diameter approximately 0.265 km. from weighted mean H=20.52.
2018 XE5JPL Sentry17302029-207921.0595e-09-5.39-5.570JPL: Computed at 08:27 today Pacific time based on 17 observations spanning 4.0067 days (2018-Dec-13.21052 to 2018-Dec-17.217264). Diameter approximately 0.620 km. from weighted mean H=18.69.
2014 JT79JPL Sentry17302018-211611321.8690016e-06-6.29-7.510JPL: Computed at 19:19 April 6th of 2017 Pacific time based on 11 observations spanning 2.8075 days (2014-May-02.40649 to 2014-May-05.21401). Diameter approximately 0.013 km. from weighted mean H=27.12.

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 17 December '18

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

2102Grabbed MPEC 2018-Y24 - Comet C/2018 X3 (Panstarrs) - see above
1940Generated Traffic Report
1730Noted that JPL Sentry has updated its 2014 JT79 risk assessment - see above
Noted that JPL Sentry has posted 2018 XE5 as an impact risk - see above
Noted that JPL Sentry has posted 2018 XG5 as an impact risk - see above
Noted that JPL Sentry has posted 2018 XN5 as an impact risk - see above
Grabbed MPEC 2018-Y13 - Daily Orbit Update - see above
Grabbed MPEC 2018-Y14 - 2018 VG18 - see above
Grabbed MPEC 2018-Y15 - 2018 XF5 - see above
Grabbed MPEC 2018-Y16 - 2018 XG5 - see above
Grabbed MPEC 2018-Y17 - 2018 XH5 - see above
Grabbed MPEC 2018-Y18 - 2018 XJ5 - see above
Grabbed MPEC 2018-Y19 - 2018 XK5 - see above
Grabbed MPEC 2018-Y20 - 2018 XL5 - see above
Grabbed MPEC 2018-Y21 - 2018 XM5 - see above
Grabbed MPEC 2018-Y22 - 2018 XN5 - see above
Grabbed MPEC 2018-Y23 - 2018 XE5 - see above