Contents  on 6 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 6 September '18

Four objects reported inside ten LD

Four asteroidal objects are known to be within ten lunar distances (LD) of Earth today. Closest is risk-listed intruder 2018 RC, moving inward from 4.05 to 2.93 LD.

Neighborhood Traffic - sorted by Earth passage distance, grouped by 1.0, 5.0 & 10.0 LD boundaries
Earth passage I D ~Size Distance today  Inside ten LD Notes
0.58 LD Sept. 9 2018 RC 40 m  2.93 from 4.05 LD Aug. 31 - Sept. 18 intruder, NHATS target, risk - DOU
3.03 LD Sept. 1 2018 RA 15 m  7.75 to 9.18 LD Aug. 26 - tomorrow
7.80 LD Aug. 23 2018 PU23 8 m  8.85 to 8.99 LD Aug. 7 - Sept. 13 NHATS target, risk
9.36 LD Aug. 27 2018 LQ2 37 m  9.94 to 10.09 LD Aug. 17 - today NHATS target, exits ten LD - DOU
Approaching Traffic
8.50 LD Sept. 20 2017 SL16 23 m  21.47 from 22.77 LD Sept. 17 - 24 NHATS target

This report was generated at 1840 UTC with follow-up in today's DOU MPEC for inbound 2018 RC, outbound 2018 LQ2, and for departed objects 2018 QW1 and risk-listed 2018 NL (25.00 days added to 39.16-day observing arc).



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.

Radar Astrometry  on 6 September '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 2303 UTC when the database was dated 6 Sept.



Photometry and some astrometry is needed for upcoming radar targets. See Arecibo and Goldstone schedules.

NEOCP Activity  on 6 September '18

The MPC's NEO Confirmation Page has 46 listings

When last checked at 2358 UTC today, the Minor Planet Center's Near Earth Object discovery Confirmation Page (NEOCP) had 46 objects listed. Of these, 30 were "one nighters." So far The Tracking News has counted a total of 50 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 6 September '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 6 Sept. '18 >>  MPEC 2018-R23 - "12:05 UT" - Daily Orbit Update

Observers  on 6 September '18

A total of 25 observers appear in today's MPEC.

CodeObserver / observatory
H21Astronomical Research Obs. Westfield in Illinois, 8 in MPEC 2018-R23 -- 2018 PT10, 2018 PL23, 2018 PK10, 2013 SS19, 2013 MR, 2008 OP8, 509456, 277958
T08ATLAS Mauna Loa in Hawaii, 8 in MPEC 2018-R23 -- 66008, 54401, 455550, 413260, 16834, 115052, 3552, 1981
160Castelmartini Obs. in Italy, 8 in MPEC 2018-R23 -- 2018 QW1, 2018 LQ2, 2018 KE3, 86324, 518635, 438429, 17274, 163132
703Catalina Sky Survey (CSS) in Arizona, 8 in MPEC 2018-R23 -- 2018 RF, 65996, 53789, 503960, 16834, 3691, 2061, 433
807|Robert Holmes in Illinois via Cerro Tololo Inter-American Obs. (CTIO) in Chile, 10 in MPEC 2018-R23 -- 2018 PY21, 2018 PS24, 2018 PO9, 2018 PF21, 2018 PE21, 2018 PA22, 2018 NB4, 2018 MO5, 2018 LR15, 2018 GT1
113Drebach Obs. in Germany, 11 in MPEC 2018-R23 -- 2018 RC, 2018 QV1, 2018 QU1, 2018 MM8, 2018 KE3, 2015 RJ83, 2015 AX16, 2013 EP41, 2011 UA, 2005 RB, 1999 RB32
151Eschenberg Obs. in Switzerland, 2 in MPEC 2018-R23 -- 2015 RJ83, 2013 EP41
595Farra d'Isonzo Obs. in Italy, 1 in MPEC 2018-R23 -- 2018 QV1
253Goldstone DSS-14 70m antenna in southern California, 1 in radar -- 2018 RC
J95Great Shefford Obs. in England, 1 in MPEC 2018-R23 -- 2018 RC
A17Guidestar Obs. in Germany, 2 in MPEC 2018-R23 -- 2018 RC, 2018 LQ2
W19Kalamazoo Obs. in Michigan, 1 in MPEC 2018-R23 -- 719
Z43Landehen Obs., 4 in MPEC 2018-R23 -- 2018 LQ2, 2015 FP118, 481394, 140039
474Mt. John Obs. in New Zealand, 9 in MPEC 2018-R23 -- 2018 PX23, 2018 PV21, 2018 PU21, 2018 PL23, 2018 PG9, 2018 MO5, 2018 MH, 2018 FH, 2011 CX46
K74Muensterschwarzach Obs. in Germany, 1 in MPEC 2018-R23 -- 2015 FP118
G34Oberfrauendorf Obs. in Germany, 4 in MPEC 2018-R23 -- 2018 LQ2, 2018 KE3, 418929, 13553
I41Palomar Transient Factory (PTF) in southern California, 8 in MPEC 2018-R23 -- 2004 QB17, 2001 SK276, 68359, 385268, 283729, 20790, 144332, 5751
K61Rokycany Obs. in the Czech Republic, 2 in MPEC 2018-R23 -- 2018 RB, 2018 QU1
C95SATINO-1 in France, 1 in MPEC 2018-R23 -- 2015 FP118
691Spacewatch 0.9m telescope in Arizona, 1 in MPEC 2018-R23 -- 2018 KB1
291Spacewatch 1.8m telescope in Arizona, 5 in MPEC 2018-R23 -- 2018 PF8, 2018 GA, 2015 JY1, 2014 YB35, 2014 US
I52Steward Obs. Mt. Lemmon Station in Arizona, 9 in MPEC 2018-R23 -- 2018 RB, 2018 QV1, 2018 QT1, 2018 QE1, 2018 PX23, 2018 PV10, 2018 PT21, 2018 OB1, 2018 KB1
T12UH/Tholen NEO Follow-Up 2.24m Telescope in Hawaii, 2 in MPEC 2018-R23 -- 2018 NL, 2018 ED4
Z92West Park Obs. in England, 1 in MPEC 2018-R23 -- 2015 FP118
718Wiggins Obs. in Utah, 2 in MPEC 2018-R23 -- 2018 LQ2, 144332
For a list of all participating observatories that have Web addresses, see A/CC's Observatory Links page.

Impact Risk Monitoring  on 6 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 RCJPL Sentry1600R E M O V E DJPL: Risk listing removed at 1504 UTC today
NEODyS1600209211.42e-08-8.04-8.040NEODyS: "Based on 56 optical observations (of which 0 are rejected as outliers) from 2018-09-03.586 to 2018-09-04.987."
2018 QSNEODyS16002084-211638.13e-07-6.93-7.110NEODyS: "Based on 59 optical observations (of which 0 are rejected as outliers) from 2018-08-18.481 to 2018-09-04.287."
2018 NLJPL Sentry16002060-2108117.18206e-05-4.43-4.700JPL: Computed at 07:41 today Pacific time based on 34 observations spanning 64.153 days (2018-Jul-03.40294 to 2018-Sep-05.556332). Diameter approximately 0.028 km. from weighted mean H=25.37.

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 6 September '18

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

2303Noted Radar Astrometry database update - see above
1840Generated Traffic Report
1600Noted that JPL Sentry has updated its 2018 NL risk assessment - see above
Noted that NEODyS has updated its 2018 QS risk assessment - see above
Noted that JPL Sentry has removed 2018 RC as an impact risk - see above
Noted that NEODyS has posted 2018 RC as an impact risk - see above
Grabbed MPEC 2018-R23 - Daily Orbit Update - see above