Contents  on 16 September '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 16 September '18

Nineteen objects reported inside ten LD

Bulletin - 2232, updated 2301 & 2345 UTC:  Three new discoveries of close passers have been announced, but too late to process for today's traffic report.

Earth passageI D~Size~Inside ten LDNotes
1.23 LD at 2323 UTC Sept. 132018 RE813 m Sept. 9 - 19MPEC
1.37 LD at 0538 UTC Sept. 192018 RF823 m today - Sept. 22MPEC
3.54 LD at 2245 UTC today2018 RG815 m Sept. 10 - 23MPEC


There are nineteen asteroids reported passing less than ten lunar distances (LD) from Earth today, including probably two and maybe three newly announced discoveries (see above bulletin). Nearest of all of these is 2018 RB6, which comes its closest to our planet on this passage, reaching 1.52 LD within Earth's sphere of gravitational influence at 0457 UTC.

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
0.58 LD Sept. 9 2018 RC 36 m  7.40 to 8.52 LD Aug. 31 - Sept. 18 intruder, NHATS target
1.48 LD yesterday 2018 RE5 11 m  3.26 to 6.51 LD Sept. 12 - 18 Moon buzzer - DOU
1.52 LD today 2018 RB6 23 m  1.52 LD Sept. 12 - 19 Moon closest 1.84 LD at 0400 UTC, Earth closest at 0457 UTC
1.64 LD Sept. 12 2018 RT5 22 m  8.14 to 10.18 LD Sept. 7 - 16 exits ten LD - DOU
1.84 LD Sept. 13 2018 RE3 13 m  5.97 to 8.19 LD Sept. 9 - 17 NHATS target
2.03 LD today 2018 RN7 11 m  2.03 LD Sept. 14 - 19 NEW, Moon closest 3.06 LD at 1817 UTC, Earth closest at 1824 UTC - MPEC
2.28 LD Sept. 9 2018 RD4 7 m  8.93 to 10.23 LD Sept. 2 - 16 NHATS target, exits ten LD
2.41 LD tomorrow 2018 RK6 9 m  2.49 from 3.16 LD Sept. 10 - 24 NHATS target - DOU
2.45 LD Sept. 11 2018 RB1 10 m  8.39 to 10.15 LD Sept. 6 - 16 NHATS target, exits ten LD
2.78 LD tomorrow 2018 RM7 8 m  2.91 from 5.51 LD Sept. 14 - 19 NEW - MPEC
3.22 LD Sept. 12 2018 RR4 13 m  7.59 to 9.43 LD Sept. 7 - 17 DOU
4.06 LD Sept. 24 2018 RQ1 52 m  6.80 from 7.36 LD Sept. 11 - Oct. 8 NHATS target, risk - DOU
4.39 LD Sept. 12 2018 RD5 23 m  7.15 to 8.35 LD Sept. 5 - 18 NHATS target - DOU
4.50 LD today 2018 RG5 15 m  4.50 LD Sept. 11 - 21 NHATS target, Earth closest at 1828 UTC - DOU
8.00 LD today 2018 RA2 27 m  8.00 LD Sept. 13 - 19 NHATS target, Earth closest at 1904 UTC
9.74 LD yesterday 2018 RQ2 89 m  9.96 to 11.11 LD Sept. 14 - 16 exits ten LD

This report was generated at 2240 UTC with two discoveries announced late yesterday: inbound 2018 RM7 (MPEC) and passing 2018 RN7 (MPEC), and with follow-up in today's DOU MPEC for eight objects active in the traffic tables here and for fifteen departed objects: 2018 RR5, 2018 RO5, 2018 RE4, 2018 RY3, 2018 RN1, 2018 LQ2, 2015 SW6, and including three intruders: 2018 RY5, 2018 RR1, and risk-listed 2018 RJ3, and five others with impact solutions: 2018 RP5, 2018 RF5, 2018 RH3, 2018 RB2, and 2018 QS.

Approaching Traffic - sorted by 10-LD bubble entry date
8.50 LD Sept. 20 2017 SL16 23 m  10.16 from 11.00 LD tomorrow - Sept. 24 NHATS target
8.56 LD Sept. 22 2018 RH6 11 m  11.64 from 12.61 LD Sept. 19 - 26 NHATS target - DOU



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 16 September '18

The MPC's NEO Confirmation Page has 36 listings

When last checked at 2358 UTC today, the Minor Planet Center's Near Earth Object discovery Confirmation Page (NEOCP) had 36 objects listed. Of these, sixteen were "one nighters." So far The Tracking News has counted a total of 60 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 16 September '18

Minor Planet Electronic Circulars

As of last check at 2358 UTC, there have been 21 MPECs posted today from the International Astronomical Union's Minor Planet Center in Cambridge, Massachusetts.


MPEC 2018-S21 - "22:33 UT" - 2018 RE8


MPEC 2018-S20 - "22:29 UT" - 2018 RC8


MPEC 2018-S19 - "22:26 UT" - 2018 RB8


MPEC 2018-S18 - "22:22 UT" - 2018 RG8


MPEC 2018-S17 - "22:18 UT" - 2018 RT7


MPEC 2018-S16 - "22:14 UT" - 2018 RF8


MPEC 2018-S15 - "22:10 UT" - 2018 RD8


MPEC 2018-S14 - "22:06 UT" - 2018 RA8


MPEC 2018-S13 - "22:02 UT" - 2018 RZ7


MPEC 2018-S12 - "21:57 UT" - 2018 RY7


MPEC 2018-S11 - "21:52 UT" - 2018 RX7


MPEC 2018-S10 - "21:47 UT" - 2018 RW7


MPEC 2018-S09 - "21:42 UT" - 2018 RV7


MPEC 2018-S08 - "21:37 UT" - 2018 RU7


MPEC 2018-S07 - "21:31 UT" - 2018 RS7


MPEC 2018-S06 - "21:27 UT" - 2018 RR7


MPEC 2018-S05 - "20:07 UT" - Comet C/2018 R4 (Fuls)


MPEC 2018-S04 - "16:47 UT" - Comet C/2018 R3 (Lemmon)


MPEC 2018-S03 - "15:24 UT" - Comet P/2011 W2 = 2018 R2 (Rinner)


<< DOU on 16 Sept. '18 >>  MPEC 2018-S02 - "12:06 UT" - Daily Orbit Update


MPEC 2018-S01 - "00:28 UT" - Comet P/2008 O2 = P/2018 P6 (McNaught)

Observers  on 16 September '18

A total of 49 observers appear in today's MPECs.

CodeObserver / observatory
L2729PREMOTE Obs., 1 in MPEC 2018-S04 -- C/2018 R3
K40Altdorf Obs. in Germany, 2 in MPEC 2018-S02 -- 2015 FP118, 144332
H21Astronomical Research Obs. Westfield in Illinois, 15 in MPECs 2018-S02, 2018-S07, 2018-S08, 2018-S09, 2018-S10, 2018-S11, 2018-S12, 2018-S13, 2018-S14, 2018-S15, 2018-S16, 2018-S17, 2018-S19, 2018-S20 & 2018-S21 -- 2018 RZ7, 2018 RY7, 2018 RX7, 2018 RW7, 2018 RV7, 2018 RU7, 2018 RT7, 2018 RS7, 2018 RF8, 2018 RE8, 2018 RD8, 2018 RC8, 2018 RB8, 2018 RA8, 2015 SW6
T05ATLAS Haleakala in Hawaii, 1 in MPEC 2018-S02 -- 413260
T08ATLAS Mauna Loa in Hawaii, 39 in MPECs 2018-S02 & 2018-S16 -- 2018 RR5, 2018 RQ5, 2018 RQ1, 2018 RF8, 2018 RD5, 2018 QV1, 2018 NB, 2018 LQ2, 2015 RJ83, 2013 EP41, 2008 RT26, 2007 RX19, 2005 RB, 2004 QJ7, 2001 SC170, 2001 RQ17, 438429, 337252, 337248, 333889, 31345, 267729, 253062, 21277, 18109, 17511, 17274, 17182, 162168, 140039, 13553, 12711, 11500, 9856, 6456, 5786, 5653, 4183, 719
069Baldone Obs. in Latvia, 1 in MPEC 2018-S02 -- 2001 SR263
215Buchloe Obs. in Germany, 1 in MPEC 2018-S05 -- C/2018 R4
W96Campo Catino Austral Obs. in Chile, 1 in MPEC 2018-S05 -- C/2018 R4
160Castelmartini Obs. in Italy, 1 in MPEC 2018-S02 -- 2018 RT5
703Catalina Sky Survey (CSS) in Arizona, 44 in MPECs 2018-S02, 2018-S05, 2018-S16 & 2018-S21 -- 2018 RT5, 2018 RL2, 2018 RG5, 2018 RF8, 2018 RE8, C/2018 R4, 2018 PJ22, 2018 LQ2, 2018 KE3, 2015 FP118, 2015 AX16, 2014 MP60, 2011 UA, 2010 VB72, 2009 SX1, 2007 RZ8, 2004 QB17, 2003 RM, 2001 SK276, 1999 VQ11, 518635, 481542, 457260, 438429, 418929, 414903, 349507, 337248, 250162, 20790, 16816, 163818, 162215, 159495, 153591, 12538, 115052, 105140, 9856, 5143, 3752, 3691, 2061, 1865
V06Catalina Sky Survey Kuiper Telescope (CSS-Kuiper) in Arizona, 7 in MPECs 2018-S02, 2018-S07, 2018-S09 & 2018-S17 -- 2018 RV7, 2018 RT7, 2018 RS7, 2018 RN1, 2018 RJ3, 2018 RF5, 2018 RE4
309'Martin Altmann in Germany via Cerro Paranal in Chile, 2 in MPECs 2018-S01 & 2018-S07 -- 2018 RS7, P/2018 P6
J04ESA Optical Ground Station in the Canary Islands, 1 in MPEC 2018-S05 -- C/2018 R4
734Farpoint Obs. in Kansas, 7 in MPECs 2018-S09, 2018-S10, 2018-S11, 2018-S14, 2018-S15, 2018-S18 & 2018-S20 -- 2018 RX7, 2018 RW7, 2018 RV7, 2018 RG8, 2018 RD8, 2018 RC8, 2018 RA8
595Farra d'Isonzo Obs. in Italy, 3 in MPECs 2018-S04, 2018-S05 & 2018-S16 -- 2018 RF8, C/2018 R4, C/2018 R3
K88GINOP-KHK in Hungary, 4 in MPECs 2018-S04, 2018-S05, 2018-S16 & 2018-S21 -- 2018 RF8, 2018 RE8, C/2018 R4, C/2018 R3
J95Great Shefford Obs. in England, 1 in MPEC 2018-S15 -- 2018 RD8
A17Guidestar Obs. in Germany, 1 in MPEC 2018-S16 -- 2018 RF8
U695Hidetaka Sato in Japan via iTelescope Obs. Auberry in northern California, 1 in MPEC 2018-S05 -- C/2018 R4
Q621Hidetaka Sato in Japan via iTelescope Obs. Siding Spring in New South Wales, 1 in MPEC 2018-S04 -- C/2018 R3
P93JAXA Space Tracking & Communications Center in Japan, 1 in MPEC 2018-S18 -- 2018 RG8
W19Kalamazoo Obs. in Michigan, 1 in MPEC 2018-S02 -- 144332
Z43Landehen Obs., 3 in MPEC 2018-S02 -- 2018 RD5, 2018 QV1, 162168
C10Maisoncelles Obs. in France, 2 in MPECs 2018-S03 & 2018-S05 -- C/2018 R4, P/2018 R2
C41MASTER-II Kislovodsk in Russia, 1 in MPEC 2018-S02 -- 163818
711McDonald Obs. in Texas, 7 in MPECs 2018-S04, 2018-S05, 2018-S09, 2018-S10, 2018-S12, 2018-S14 & 2018-S17 -- 2018 RY7, 2018 RW7, 2018 RV7, 2018 RT7, 2018 RA8, C/2018 R4, C/2018 R3
474Mt. John Obs. in New Zealand, 10 in MPECs 2018-S02, 2018-S04, 2018-S09, 2018-S10 & 2018-S11 -- 2018 RY5, 2018 RX7, 2018 RW7, 2018 RV7, 2018 RU3, 2018 RR5, 2018 RQ5, 2018 RP5, 2018 RE5, C/2018 R3
G96Mt. Lemmon Survey (MLS) in Arizona, 45 in MPECs 2018-S02, 2018-S04, 2018-S05, 2018-S06, 2018-S08, 2018-S09, 2018-S10, 2018-S11, 2018-S12, 2018-S13, 2018-S14, 2018-S15, 2018-S17, 2018-S19, 2018-S20 & 2018-S21 -- 2018 RZ7, 2018 RY7, 2018 RY5, 2018 RX7, 2018 RX, 2018 RW7, 2018 RV7, 2018 RU7, 2018 RT7, 2018 RR7, 2018 RQ5, 2018 RQ1, 2018 RE8, 2018 RD8, 2018 RC8, 2018 RB8, 2018 RA8, C/2018 R4, C/2018 R3, 2018 PS7, 2018 PK22, 2018 KR2, 2015 TW143, 2015 TN237, 2015 RJ83, 2014 GF50, 2013 EP41, 2011 CX46, 2008 RT26, 2005 RV24, 518463, 476438, 468684, 422977, 419022, 363069, 337252, 253106, 17511, 17182, 162687, 5786, 5653, 4953, 4183
Q33Nayoro Obs. in Japan, 1 in MPEC 2018-S02 -- 2018 RR4
J69North Obs. in England, 1 in MPEC 2018-S02 -- 2018 RO5
C23Olmen Obs. in Belgium, 2 in MPEC 2018-S02 -- 2011 UA, 144332
I41Palomar Transient Factory (PTF) in southern California, 13 in MPECs 2018-S02, 2018-S18 & 2018-S21 -- 2018 RL, 2018 RG8, 2018 RF6, 2018 RE8, 2018 PE22, 2018 MM8, 2001 SK276, 68950, 283729, 163902, 162687, 4953, 3691
F51Pan-STARRS 1 (PS1) in Hawaii, 2 in MPECs 2018-S01 & 2018-S04 -- C/2018 R3, P/2018 P6
K63Pascoli Obs. in Italy, 2 in MPECs 2018-S04 & 2018-S05 -- C/2018 R4, C/2018 R3
K81PMPHR Obs., 1 in MPEC 2018-S02 -- 418929
D29Purple Mtn. Obs. Xuyi Station in China, 1 in MPEC 2018-S05 -- C/2018 R4
K61Rokycany Obs. in the Czech Republic, 1 in MPEC 2018-S05 -- C/2018 R4
104San Marcello Pistoiese Obs. in Italy, 5 in MPECs 2018-S04, 2018-S05, 2018-S15, 2018-S16 & 2018-S21 -- 2018 RF8, 2018 RE8, 2018 RD8, C/2018 R4, C/2018 R3
C95SATINO-1 in France, 1 in MPEC 2018-S02 -- 5786
033Schwarzschild Obs. in Germany, 8 in MPECs 2018-S02, 2018-S05, 2018-S08, 2018-S10, 2018-S14, 2018-S15 & 2018-S16 -- 2018 RW7, 2018 RU7, 2018 RO7, 2018 RF8, 2018 RD8, 2018 RC7, 2018 RA8, C/2018 R4
G40"G. Gasparovic in Croatia via Slooh.com Canary Islands Obs. in the Canary Islands, 1 in MPEC 2018-S05 -- C/2018 R4
G409B. Lutkenhoner in Germany via Slooh.com Canary Islands Obs. in the Canary Islands, 2 in MPECs 2018-S04 & 2018-S05 -- C/2018 R4, C/2018 R3
691Spacewatch 0.9m telescope in Arizona, 6 in MPECs 2018-S02 & 2018-S04 -- 2018 RM2, C/2018 R3, 2018 NN4, 2018 MS6, 2018 FY1, 3352
291Spacewatch 1.8m telescope in Arizona, 11 in MPECs 2018-S02 & 2018-S07 -- 2018 RY3, 2018 RT3, 2018 RS7, 2018 RJ3, 2018 RF5, 2018 RB2, 2018 QU, 2018 QQ, 2018 PK21, 2018 PF8, 2015 XE352
I52Steward Obs. Mt. Lemmon Station in Arizona, 38 in MPECs 2018-S02, 2018-S04, 2018-S05, 2018-S06, 2018-S08, 2018-S09, 2018-S10, 2018-S11, 2018-S12, 2018-S13, 2018-S14, 2018-S15, 2018-S16, 2018-S17, 2018-S18, 2018-S19, 2018-S20 & 2018-S21 -- 2018 RZ7, 2018 RY7, 2018 RY5, 2018 RX7, 2018 RW7, 2018 RV7, 2018 RU7, 2018 RU3, 2018 RT7, 2018 RR7, 2018 RR5, 2018 RQ5, 2018 RQ4, 2018 RP5, 2018 RO5, 2018 RO4, 2018 RO2, 2018 RM2, 2018 RL6, 2018 RK6, 2018 RJ6, 2018 RH6, 2018 RH3, 2018 RG8, 2018 RG6, 2018 RG5, 2018 RF8, 2018 RF6, 2018 RE8, 2018 RE6, 2018 RD8, 2018 RD5, 2018 RC8, 2018 RC6, 2018 RB8, 2018 RA8, C/2018 R4, C/2018 R3
A71Stixendorf Obs. in Austria, 2 in MPECs 2018-S04 & 2018-S05 -- C/2018 R4, C/2018 R3
461SZTE Asteroid Program in Hungary, 1 in MPEC 2018-S03 -- P/2018 R2
926Tenagra II Obs. in Arizona, 1 in MPEC 2018-S04 -- C/2018 R3
T12UH/Tholen NEO Follow-Up 2.24m Telescope in Hawaii, 11 in MPEC 2018-S02 -- 2018 RY1, 2018 RT3, 2018 RR1, 2018 RQ4, 2018 RQ1, 2018 RP5, 2018 RJ3, 2018 RH3, 2018 RF5, 2018 RB2, 2018 QS
L01Visnjan Obs., 14 in MPECs 2018-S02, 2018-S04, 2018-S05, 2018-S06, 2018-S08, 2018-S10, 2018-S14, 2018-S15, 2018-S16, 2018-S18, 2018-S19, 2018-S20 & 2018-S21 -- 2018 RW7, 2018 RU7, 2018 RR7, 2018 RG8, 2018 RF8, 2018 RE8, 2018 RD8, 2018 RD7, 2018 RC8, 2018 RB8, 2018 RA8, C/2018 R4, C/2018 R3, 2015 SW6
For a list of all participating observatories that have Web addresses, see A/CC's Observatory Links page.

Impact Risk Monitoring  on 16 September '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 is 100 years from today and for NEODyS is usually the year 2090. Both also post impact solutions beyond 100 years for a few 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 RJ7NEODyS16402057-209281.12e-08-6.00-6.190NEODyS: "Based on 26 optical observations (of which 0 are rejected as outliers) from 2018-09-13.263 to 2018-09-15.432."
JPL Sentry03002056-2116151.47339e-08-5.89-6.240JPL: Computed at 17:29 Sept. 15th Pacific time based on 26 observations spanning 2.1694 days (2018-Sep-13.26203 to 2018-Sep-15.43138). Diameter approximately 0.213 km. from weighted mean H=21.00.
2018 RB7NEODyS1640209312.53e-07-4.93-4.930NEODyS: "Based on 19 optical observations (of which 0 are rejected as outliers) from 2018-09-12.469 to 2018-09-15.441."
2018 RP5JPL Sentry1640R E M O V E DJPL: Risk listing removed at 1506 UTC today
2018 RF5JPL Sentry16402069-211548.4593895e-06-6.57-6.870JPL: Computed at 08:17 today Pacific time based on 41 observations spanning 4.1709 days (2018-Sep-12.23986 to 2018-Sep-16.41077). Diameter approximately 0.011 km. from weighted mean H=27.40.
NEODyS16402069-211547.9e-06-6.59-6.920NEODyS: "Based on 32 optical observations (of which 0 are rejected as outliers) from 2018-09-12.241 to 2018-09-15.336."
2018 RQ4JPL Sentry16402098-2111123.4749316e-06-6.74-7.440JPL: Computed at 08:21 today Pacific time based on 33 observations spanning 5.0578 days (2018-Sep-11.2811 to 2018-Sep-16.33885). Diameter approximately 0.014 km. from weighted mean H=26.86.
NEODyS16402074-2116162.68e-06-6.85-7.30NEODyS: "Based on 26 optical observations (of which 0 are rejected as outliers) from 2018-09-11.282 to 2018-09-15.314."
2018 RT3NEODyS1640R E M O V E D-
2018 RJ3JPL Sentry16402070-207011.345e-06-7.34-7.340JPL: Computed at 07:59 today Pacific time based on 44 observations spanning 6.8149 days (2018-Sep-09.56735 to 2018-Sep-16.38228). Diameter approximately 0.009 km. from weighted mean H=27.79.
2018 RH3NEODyS1640R E M O V E D-
2018 RB2JPL Sentry16402092-2117273.214789e-05-5.91-6.310JPL: Computed at 08:26 today Pacific time based on 50 observations spanning 9.1891 days (2018-Sep-07.26955 to 2018-Sep-16.4586). Diameter approximately 0.012 km. from weighted mean H=27.30.
2018 RY1JPL Sentry16402040-207321.2343e-07-6.46-6.530JPL: Computed at 08:08 today Pacific time based on 62 observations spanning 8.1229 days (2018-Sep-07.13874 to 2018-Sep-15.261597). Diameter approximately 0.045 km. from weighted mean H=24.40.
NEODyS16402040-209582.42e-07-6.18-6.490NEODyS: "Based on 59 optical observations (of which 0 are rejected as outliers) from 2018-09-07.140 to 2018-09-15.165."
2018 RR1JPL Sentry16402086-2118162.4489383e-05-7.42-7.530JPL: Computed at 07:59 today Pacific time based on 31 observations spanning 8.0739 days (2018-Sep-07.39342 to 2018-Sep-15.467288). Diameter approximately 0.004 km. from weighted mean H=29.94.
2018 RQ1JPL Sentry1640R E M O V E DJPL: Risk listing removed at 1500 UTC today
NEODyS16402117-211821.43e-07-6.94-6.94n/aNEODyS: "Based on 80 optical observations (of which 0 are rejected as outliers) from 2018-09-07.381 to 2018-09-15.380."
2018 QSJPL Sentry16402084-211623.1711e-06-6.31-6.370JPL: Computed at 07:44 today Pacific time based on 74 observations spanning 27.980 days (2018-Aug-18.47984 to 2018-Sep-15.460074). Diameter approximately 0.019 km. from weighted mean H=26.24.
NEODyS16402084-211622.07e-06-6.50-6.570NEODyS: "Based on 71 optical observations (of which 0 are rejected as outliers) from 2018-08-18.481 to 2018-09-12.330."

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 16 September '18

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

2300Grabbed MPEC 2018-S20 - 2018 RC8 - see above
Grabbed MPEC 2018-S21 - 2018 RE8 - see above
2240Generated Traffic Report
2230Grabbed MPEC 2018-S14 - 2018 RA8 - see above
Grabbed MPEC 2018-S15 - 2018 RD8 - see above
Grabbed MPEC 2018-S16 - 2018 RF8 - see above
Grabbed MPEC 2018-S17 - 2018 RT7 - see above
Grabbed MPEC 2018-S18 - 2018 RG8 - see above
Grabbed MPEC 2018-S19 - 2018 RB8 - see above
2203Grabbed MPEC 2018-S07 - 2018 RS7 - see above
Grabbed MPEC 2018-S08 - 2018 RU7 - see above
Grabbed MPEC 2018-S09 - 2018 RV7 - see above
Grabbed MPEC 2018-S10 - 2018 RW7 - see above
Grabbed MPEC 2018-S11 - 2018 RX7 - see above
Grabbed MPEC 2018-S12 - 2018 RY7 - see above
Grabbed MPEC 2018-S13 - 2018 RZ7 - see above
2130Grabbed MPEC 2018-S06 - 2018 RR7 - see above
2037Grabbed MPEC 2018-S05 - Comet C/2018 R4 (Fuls) - see above
1730Grabbed MPEC 2018-S04 - Comet C/2018 R3 (Lemmon) - see above
1640Noted that JPL Sentry has updated its 2018 QS risk assessment - see above
Noted that NEODyS has updated its 2018 QS risk assessment - see above
Noted that JPL Sentry has updated its 2018 RB2 risk assessment - see above
Noted that NEODyS has posted 2018 RB7 as an impact risk - see above
Noted that JPL Sentry has updated its 2018 RF5 risk assessment - see above
Noted that NEODyS has updated its 2018 RF5 risk assessment - see above
Noted that NEODyS has removed 2018 RH3 as an impact risk - see above
Noted that JPL Sentry has updated its 2018 RJ3 risk assessment - see above
Noted that NEODyS has posted 2018 RJ7 as an impact risk - see above
Noted that JPL Sentry has removed 2018 RP5 as an impact risk - see above
Noted that JPL Sentry has removed 2018 RQ1 as an impact risk - see above
Noted that NEODyS has updated its 2018 RQ1 risk assessment - see above
Noted that JPL Sentry has updated its 2018 RQ4 risk assessment - see above
Noted that NEODyS has updated its 2018 RQ4 risk assessment - see above
Noted that JPL Sentry has updated its 2018 RR1 risk assessment - see above
Noted that NEODyS has removed 2018 RT3 as an impact risk - see above
Noted that JPL Sentry has updated its 2018 RY1 risk assessment - see above
Noted that NEODyS has updated its 2018 RY1 risk assessment - see above
Grabbed MPEC 2018-S02 - Daily Orbit Update - see above
Grabbed MPEC 2018-S03 - Comet P/2011 W2 = 2018 R2 (Rinner) - see above
0300Noted that JPL Sentry has posted 2018 RJ7 as an impact risk - see above
Grabbed MPEC 2018-S01 - Comet P/2008 O2 = P/2018 P6 (McNaught) - see above