Contents  on 28 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 28 December '18

Four objects reported inside ten LD

There are four asteroidal objects reported to be less than ten lunar distances (LD) from our home world today, all of them outbound and more than five LD away.

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
2.62 LD Dec. 15 2018 VO9 14 m  8.24 to 8.81 LD Nov. 29 - Dec. 31 NHATS target, risk
2.96 LD Dec. 24 2018 XN5 28 m  5.48 to 6.71 LD Dec. 18 - 31 NHATS target, risk
3.92 LD Dec. 2 2018 TG6 12 m  8.09 to 8.33 LD Oct. 30 - Jan. 5 NHATS target
5.3   LD Dec. 26* 2018 XE4 17 m  5.9 to 7.0 LD Dec. 22 - 30 EPU +/- 3.33 hours*
* EPU = Earth passage uncertainty

This report was generated at 1941 UTC with follow-up in today's DOU MPEC for departed 2018 XB5 and distant 68216 2001 CV26.

Approaching - sorted by 10-LD bubble entry date
Earth passage I D ~Size Distance today  Inside ten LD Notes
7.8   LD Jan. 6* 2018 XO4 30 m  11.1 from 11.8 LD Dec. 30 - Jan. 13 EPU +/- 17 mins.*, NHATS target
7.3   LD Jan. 9* 2013 YM2 19 m  13.3 from 14.2 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. "Distant" is used here to describe an object that has come within ten LD since A/CC began these traffic reports (2007) but is not so close now. 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.

NEOCP Activity  on 28 December '18

The MPC's NEO Confirmation Page has 5 listings

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

Minor Planet Electronic Circulars

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


MPEC 2018-Y91 - "15:56 UT" - 2018 YJ2


<< DOU on 28 Dec. '18 >>  MPEC 2018-Y90 - "13:06 UT" - Daily Orbit Update


MPEC 2018-Y89 - "12:38 UT" - 2017 VU14


MPEC 2018-Y88 - "12:36 UT" - 2017 TV4


MPEC 2018-Y87 - "12:34 UT" - 2017 SO17


MPEC 2018-Y86 - "12:31 UT" - 2016 PL66


MPEC 2018-Y85 - "12:29 UT" - 2014 MM55


MPEC 2018-Y84 - "03:55 UT" - 2018 XB20

Observers  on 28 December '18

A total of 26 observers appear in today's MPECs.

CodeObserver / observatory
H21Astronomical Research Obs. Westfield in Illinois, 9 in MPEC 2018-Y90 -- 2018 XR3, 2018 XR, 2018 VZ1, 2014 WZ200, 2013 VE13, 2011 HE24, 2005 WF4, 285331, 276111
T05ATLAS Haleakala in Hawaii, 5 in MPECs 2018-Y90 & 2018-Y91 -- 2018 YJ2, 2018 XB2, 2018 WR1, 2018 TC3, 2002 XQ90
T08ATLAS Mauna Loa in Hawaii, 1 in MPEC 2018-Y91 -- 2018 YJ2
160Castelmartini Obs. in Italy, 20 in MPEC 2018-Y90 -- 2018 XZ2, 2018 WR1, 2018 TS, 2010 AK, 2007 YQ56, 68216, 457260, 450238, 418849, 412995, 345722, 345705, 217807, 18109, 154656, 141498, 136793, 2061, 1943, 1916
V06Catalina Sky Survey Kuiper Telescope in Arizona, 1 in MPEC 2018-Y84 -- 2018 XB20
807|Robert Holmes in Illinois via Cerro Tololo Inter-American Obs. (CTIO) in Chile, 22 in MPECs 2018-Y84, 2018-Y86 & 2018-Y90 -- 2018 YY, 2018 YU, 2018 XO, 2018 XK5, 2018 XG5, 2018 XD, 2018 XB5, 2018 XB20, 2018 WY2, 2018 WW1, 2018 WH2, 2018 VQ3, 2018 VN3, 2018 VF6, 2018 TW, 2018 RV5, 2018 RB8, 2018 PM9, 2018 NS3, 2018 NR4, 2016 PL66, 2013 BG27
Z45Cosmos Obs., 1 in MPEC 2018-Y90 -- 2003 NW1
595Farra d'Isonzo Obs. in Italy, 1 in MPEC 2018-Y91 -- 2018 YJ2
K88GINOP-KHK in Hungary, 1 in MPEC 2018-Y91 -- 2018 YJ2
J95Great Shefford Obs. in England, 2 in MPECs 2018-Y90 & 2018-Y91 -- 2018 YJ2, 2018 YF2
P93JAXA Space Tracking & Communications Center in Japan, 1 in MPEC 2018-Y91 -- 2018 YJ2
K38M57 Obs. in Italy, 3 in MPECs 2018-Y90 & 2018-Y91 -- 2018 YS, 2018 YJ2, 2018 VW6
H01Magdalena Ridge Obs. in New Mexico, 1 in MPEC 2018-Y84 -- 2018 XB20
D54MASTER-II Blagoveshchensk in Russia, 1 in MPEC 2018-Y90 -- 457260
G96Mt. Lemmon Survey in Arizona, 1 in MPEC 2018-Y84 -- 2018 XB20
F51Pan-STARRS 1 (PS1) in Hawaii, 6 in MPECs 2018-Y85, 2018-Y87, 2018-Y88, 2018-Y89 & 2018-Y90 -- 2017 VU14, 2017 TV4, 2017 SO17, 2014 MM55, 2013 BG27, 1982 YA
F52Pan-STARRS 2 in Hawaii, 1 in MPEC 2018-Y84 -- 2018 XB20
104San Marcello Pistoiese Obs. in Italy, 1 in MPEC 2018-Y91 -- 2018 YJ2
C95SATINO-1 in France, 2 in MPECs 2018-Y90 & 2018-Y91 -- 2018 YJ2, 2011 XE1
G409B. Lutkenhoner in Germany via Slooh.com Canary Islands Obs. in the Canary Islands, 1 in MPEC 2018-Y91 -- 2018 YJ2
587Sormano Obs. in Italy, 1 in MPEC 2018-Y91 -- 2018 YJ2
Q21Southern Utsunomiya in Japan, 1 in MPEC 2018-Y90 -- 3200
W34Squirrel Valley Obs. in North Carolina, 1 in MPEC 2018-Y91 -- 2018 YJ2
T12UH/Tholen NEO Follow-Up 2.24m Telescope in Hawaii, 1 in MPEC 2018-Y90 -- 2018 VG8
L01Visnjan Obs., 1 in MPEC 2018-Y91 -- 2018 YJ2
718Wiggins Obs. in Utah, 1 in MPEC 2018-Y91 -- 2018 YJ2
For a list of all participating observatories that have Web addresses, see A/CC's Observatory Links page.

Impact Risk Monitoring  on 28 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 XG5JPL Sentry17302083-208313.012e-07-4.32-4.320JPL: Computed at 07:43 today Pacific time based on 32 observations spanning 14.713 days (2018-Dec-13.39431 to 2018-Dec-28.10728). Diameter approximately 0.300 km. from weighted mean H=20.29.

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 '18

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

1941Generated Traffic Report
1730Noted that JPL Sentry has updated its 2018 XG5 risk assessment - see above
Grabbed MPEC 2018-Y85 - 2014 MM55 - see above
Grabbed MPEC 2018-Y86 - 2016 PL66 - see above
Grabbed MPEC 2018-Y87 - 2017 SO17 - see above
Grabbed MPEC 2018-Y88 - 2017 TV4 - see above
Grabbed MPEC 2018-Y89 - 2017 VU14 - see above
Grabbed MPEC 2018-Y90 - Daily Orbit Update - see above
Grabbed MPEC 2018-Y91 - 2018 YJ2 - see above
0600Grabbed MPEC 2018-Y84 - 2018 XB20 - see above