Contents  on 2 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 2 December '18

Nine objects reported inside ten LD

Nine small visitors are reported within ten lunar distances (LD) of our planet today. By far the nearest is risk-listed intruder 2018 WV1, which whizzed by early today at 0.086 LD -- by our count the 20th closest Earth passage of a non-impacting asteroid observed by telescope. It started the day at 0.14 LD from Earth and moves out to 0.57 LD by day's end. NASA/JPL has a news item about this object, which was discussed on the Minor Planet Mailing List here, here, and here as probably a piece of ejecta from an ancient lunar impact.
        A little further out, risk-listed intruder 2018 WG2 exits our planet's sphere of gravitational influence, traveling out from 1.85 to 3.28 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 today 2018 WV1 3 m  0.09 LD Nov. 8 - Dec. 25 intruder today, NHATS target, Earth closest at 0311 UTC, Moon closest 0.88 LD at 0653 UTC, risk
0.52 LD Nov. 30 2018 WG2 3 m  1.85 to 3.28 LD Nov. 23 - Dec. 7 intruder, NHATS target, exits Earth SOI, risk
1.18 LD Nov. 25 2018 WH1 7 m  5.69 to 6.59 LD Nov. 15 - Dec. 6 Moon buzzer, NHATS target, risk
2.62 LD Dec. 15 2018 VO9 13 m  8.18 from 8.75 LD Nov. 29 - Dec. 31 NHATS target, risk
2.76 LD yesterday 2018 WF2 7 m  3.04 to 4.71 LD Nov. 27 - Dec. 5
3.42 LD Dec. 4 2018 WD2 21 m  4.69 from 5.99 LD Nov. 29 - Dec. 10 DOU
3.92 LD today 2018 TG6 12 m  3.92 LD Oct. 30 - Jan. 5 NHATS target, Earth closest at 1604 UTC
8.03 LD Nov. 30 2018 XA 70 m  9.99 to 12.36 LD Nov. 28 - today NEW, exits ten LD, risk - MPEC
8.21 LD Nov. 25 2018 VT7 9 m  8.80 to 8.99 LD Nov. 15 - Dec. 7 NHATS target

This report was updated at 2318 UTC with the discovery of outbound 2018 XA (MPEC), which passed Earth at 8.03 LD on November 30th. Your first local flying rocks traffic report was generated at 2110 UTC with follow-up in today's DOU MPEC for approaching 2018 WX1 and 2001 XG1, inbound 2018 WD2, and three departed objects: 2018 WT1, 2018 VM6, and 2008 WS62, plus astrometry from mid-November for 2018 VU8, 2018 VS8, 2018 VM6, and 2018 VY4.

Approaching - sorted by 10-LD bubble entry date
Earth passage I D ~Size Distance today  Inside ten LD Notes
4.82 LD Dec. 7 2018 WX1 55 m  10.09 from 11.92 LD tomorrow - Dec. 11 NHATS target - DOU
4.1   LD Dec. 9* 2013 VX4 62 m  10.7 from 12.1 LD tomorrow - Dec. 15 EPU +/- 2.35 days*
7.84 LD Dec. 10 2001 XG1 74 m  24.03 from 27.13 LD Dec. 8 - 12 DOU
7.36 LD Dec. 22 163899 2003 SD220 1.17 km  26.98 from 28.24 LD Dec. 17 - 26 radar/NHATS target
7.3   LD Jan. 9* 2013 YM2 19 m  36.8 from 37.7 LD Jan. 2 - 16 EPU +/- 1.25 days*, NHATS target
* EPU = Earth passage uncertainty


<< Reading:  It is with deep respect that we report the unexpected passing of Andrea Milani, the leader and co-founder of the NEODyS asteroid impact risk monitoring service, which until just recently operated out of the University of Pisa. Professor Milani with a small team invented the "virtual impactor" system used today by NEODyS and NASA/JPL to rapidly and transparently calculate whether newly discovered minor objects may present a risk to Earth, something that was much needed in the astronomy and celestial mechanics communities following a number of false scares around the turn of the century. And the results from that work have been a daily part of our reporting here beginning back in 2002. His death was reported in a Minor Planet Mailing List thread, where it was noted that the European Hera mission has posted an obituary.



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 2 December '18

The MPC's NEO Confirmation Page has 32 listings

When last checked at 2358 UTC today, the Minor Planet Center's Near Earth Object discovery Confirmation Page (NEOCP) had 32 objects listed. Of these, nineteen 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 2 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-X22 - "21:12 UT" - 2018 XA


MPEC 2018-X21 - "21:09 UT" - 2018 WP2


MPEC 2018-X20 - "21:06 UT" - 2018 WO2


MPEC 2018-X19 - "21:02 UT" - 2018 WN2


MPEC 2018-X18 - "20:58 UT" - 2018 WM2


MPEC 2018-X17 - "20:55 UT" - 2018 WL2


MPEC 2018-X16 - "20:52 UT" - 2018 WK2


<< DOU on 2 Dec. '18 >>  MPEC 2018-X15 - "13:05 UT" - Daily Orbit Update

Observers  on 2 December '18

A total of 34 observers appear in today's MPECs.

CodeObserver / observatory
834AAAA Buenos Aires Obs. in Argentina, 1 in MPEC 2018-X15 -- 88263
H21Astronomical Research Obs. Westfield in Illinois, 2 in MPEC 2018-X15 -- 2018 VY5, 2018 VS8
T05ATLAS Haleakala in Hawaii, 4 in MPECs 2018-X17, 2018-X20, 2018-X21 & 2018-X22 -- 2018 XA, 2018 WP2, 2018 WO2, 2018 WL2
T08ATLAS Mauna Loa in Hawaii, 4 in MPECs 2018-X15 & 2018-X22 -- 2018 XA, 2018 WX1, 2018 QN1, 2001 XG1
160Castelmartini Obs. in Italy, 9 in MPEC 2018-X15 -- 2018 QN1, 2014 XR6, 2010 GT7, 2001 XG1, 523587, 414960, 208617, 154656, 1943
807|Robert Holmes in Illinois via Cerro Tololo Inter-American Obs. (CTIO) in Chile, 3 in MPEC 2018-X15 -- 2018 VJ1, 2018 VH3, 2018 SZ
W84%program code "%" (14) via DECam in Chile, 1 in MPEC 2018-X15 -- 2016 JT38
157Frasso Sabino Obs. in Italy, 1 in MPEC 2018-X19 -- 2018 WN2
K88GINOP-KHK in Hungary, 4 in MPECs 2018-X17, 2018-X19, 2018-X20 & 2018-X21 -- 2018 WP2, 2018 WO2, 2018 WN2, 2018 WL2
E94Gisborne Obs. in New Zealand, 1 in MPEC 2018-X15 -- 2018 VR9
J95Great Shefford Obs. in England, 1 in MPEC 2018-X21 -- 2018 WP2
H06#M. Suzuki in Japan via iTelescope Obs. Mayhill in New Mexico, 1 in MPEC 2018-X22 -- 2018 XA
585Kiev Comet Station in Ukraine, 2 in MPEC 2018-X15 -- 2018 WC, 2011 AA37
V37LCO McDonald Obs. in Texas, 1 in MPEC 2018-X15 -- 2018 VW1
H01Magdalena Ridge Obs. (MRO) in New Mexico, 2 in MPECs 2018-X15 & 2018-X16 -- 2018 WK2, 2018 VU8
932McCarthy Obs. in Connecticut, 1 in MPEC 2018-X15 -- 2018 VM6
B67Mirasteilas Obs. in Switzerland, 1 in MPEC 2018-X15 -- 2010 GT7
G96Mt. Lemmon Survey (MLS) in Arizona, 3 in MPECs 2018-X16, 2018-X18 & 2018-X19 -- 2018 WN2, 2018 WM2, 2018 WK2
C23Olmen Obs. in Belgium, 1 in MPEC 2018-X15 -- 2003 NW1
F52Pan-STARRS 2 in Hawaii, 1 in MPEC 2018-X17 -- 2018 WL2
K63Pascoli Obs. in Italy, 3 in MPECs 2018-X16, 2018-X19 & 2018-X22 -- 2018 XA, 2018 WN2, 2018 WK2
H45Petit Jean Mtn. South Obs. (PJMSO) in Arkansas, 9 in MPEC 2018-X15 -- 2018 WX1, 2018 WT1, 2018 WR1, 2018 WD2, 2018 TS, 2018 QN1, 2010 GT7, 2010 AK, 2001 VC2
L04ROASTERR-1 in Romania, 2 in MPECs 2018-X21 & 2018-X22 -- 2018 XA, 2018 WP2
247roving observer, 1 in MPEC 2018-X15 -- 2018 VT8
B04Saint-Barthelemy Obs. in Italy, 2 in MPECs 2018-X20 & 2018-X21 -- 2018 WP2, 2018 WO2
104San Marcello Pistoiese Obs. in Italy, 4 in MPECs 2018-X15, 2018-X20 & 2018-X21 -- 2018 WP2, 2018 WO2, 2018 VY4, 2018 VJ5
H36Sandlot Obs. in Kansas, 1 in MPEC 2018-X16 -- 2018 WK2
B74Santa Maria de Montmagastrell Obs. in Spain, 1 in MPEC 2018-X21 -- 2018 WP2
C95SATINO-1 in France, 3 in MPECs 2018-X15, 2018-X17 & 2018-X20 -- 2018 WO2, 2018 WL2, 2001 VC2
033Schwarzschild Obs. in Germany, 3 in MPECs 2018-X16, 2018-X18 & 2018-X21 -- 2018 WP2, 2018 WM2, 2018 WK2
691Spacewatch 0.9m telescope in Arizona, 1 in MPEC 2018-X19 -- 2018 WN2
W34Squirrel Valley Obs. in North Carolina, 1 in MPEC 2018-X15 -- 2008 WS62
I52Steward Obs. Mt. Lemmon Station in Arizona, 4 in MPECs 2018-X16, 2018-X17, 2018-X18 & 2018-X19 -- 2018 WN2, 2018 WM2, 2018 WL2, 2018 WK2
L01Visnjan Obs., 5 in MPECs 2018-X16, 2018-X17, 2018-X19, 2018-X20 & 2018-X21 -- 2018 WP2, 2018 WO2, 2018 WN2, 2018 WL2, 2018 WK2
For a list of all participating observatories that have Web addresses, see A/CC's Observatory Links page.

Impact Risk Monitoring  on 2 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 XAJPL Sentry22312099-209928.945e-07-5.43-5.590JPL: Computed at 14:27 today Pacific time based on 32 observations spanning 1.4113 days (2018-Dec-01.34686 to 2018-Dec-02.75813). Diameter approximately 0.070 km. from weighted mean H=23.42.
2018 WV1NEODyS17002076-2117311.43e-05-7.77-8.110NEODyS: "Based on 38 optical observations (of which 0 are rejected as outliers) from 2018-11-29.235 to 2018-11-30.922."
2018 WR1JPL Sentry1700R E M O V E DJPL: Risk listing removed at 1510 UTC today
NEODyS1700R E M O V E D-
2018 WH1NEODyS17002067-2115231.53e-05-6.84-7.460NEODyS: "Based on 53 optical observations (of which 1 are rejected as outliers) from 2018-11-27.259 to 2018-11-30.914."
2018 WSNEODyS1700R E M O V E D-
2018 WJNEODyS17002045-210677.81e-07-6.99-7.360NEODyS: "Based on 78 optical observations (of which 0 are rejected as outliers) from 2018-11-17.268 to 2018-11-19.910."
2017 RH16NEODyS1700R E M O V E D-
2016 JT38JPL Sentry17002050-2111223.00636e-07-4.62-5.280JPL: Computed at 07:06 today Pacific time based on 10 observations spanning 1.9292 days (2016-May-03.37727 to 2016-May-05.30645). Diameter approximately 0.230 km. from weighted mean H=20.86.
NEODyS17002047-2111131.37e-07-4.91-5.380NEODyS: "Based on 10 optical observations (of which 0 are rejected as outliers) from 2016-05-03.378 to 2016-05-05.307."

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 2 December '18

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

2318Updated Traffic Report
2231Noted that JPL Sentry has posted 2018 XA as an impact risk - see above
2132Grabbed MPEC 2018-X19 - 2018 WN2 - see above
Grabbed MPEC 2018-X20 - 2018 WO2 - see above
Grabbed MPEC 2018-X21 - 2018 WP2 - see above
Grabbed MPEC 2018-X22 - 2018 XA - see above
2100Grabbed MPEC 2018-X16 - 2018 WK2 - see above
Grabbed MPEC 2018-X17 - 2018 WL2 - see above
Grabbed MPEC 2018-X18 - 2018 WM2 - see above
1700Noted that JPL Sentry has reposted 2016 JT38 as an impact risk - see above
Noted that NEODyS has updated its 2016 JT38 risk assessment - see above
Noted that NEODyS has removed 2017 RH16 as an impact risk - see above
Noted that NEODyS has updated its 2018 WH1 risk assessment - see above
Noted that NEODyS has updated its 2018 WJ risk assessment - see above
Noted that JPL Sentry has removed 2018 WR1 as an impact risk - see above
Noted that NEODyS has removed 2018 WR1 as an impact risk - see above
Noted that NEODyS has removed 2018 WS as an impact risk - see above
Noted that NEODyS has updated its 2018 WV1 risk assessment - see above
Grabbed MPEC 2018-X15 - Daily Orbit Update - see above