Contents  on 11 September '17

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 11 September '17

Two objects reported inside ten LD

There are two minor planets known to be moving within ten lunar distances (LD) of our planet today. 2017 RB is outbound from 6.60 to 7.58 LD and intruder 2017 QB35 from 6.80 to 7.67 LD.

Earth passage I D ~Size Distance Today  Notes
0.93 LD Sept. 32017 QB35 5 m  6.80 to 7.67 LD intruder
3.78 LD Sept. 62017 RB 8 m  6.60 to 7.58 LD
Approaching (sorted by 10-LD bubble entry date)
7.87 LD Sept. 291989 VB 389 m  < 10 LD Sept. 25, radar target - DOU
0.13 LD Oct. 122012 TC4 15 m  < 10 LD Oct. 5, intruder, radar/NHATS target, risk - DOU
8.5   LD Oct. 132005 TE49 15 m  < 10 LD Oct. 11, uncertainty +/- 10.1167 hours, NHATS target
5.77 LD Oct. 22171576 1999 VP11 645 m  < 10 LD Oct. 20

This report was generated at 1712 UTC with follow-up in today's DOU MPEC for approaching radar targets 2012 TC4 and 1989 VB.

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 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 11 September '17

The MPC's NEO Confirmation Page has 41 listings

When last checked at 2358 UTC today, the Minor Planet Center's Near Earth Object discovery Confirmation Page (NEOCP) had 41 objects listed. Of these, 21 were "one nighters." So far The Tracking News has counted a total of 47 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 11 September '17

Minor Planet Electronic Circulars

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

<< DOU on 11 Sept. '17 >>  MPEC 2017-R46 - "12:02 UT" - Daily Orbit Update

MPEC 2017-R45 - "02:54 UT" - 2013 AN20

Observers  on 11 September '17

Sixteen observers appear in today's MPECs.

CodeObserver / observatory
T05ATLAS Haleakala in Hawaii, 2 in MPEC 2017-R46 -- 68348, 1917
006Fabra Obs. in Spain, 2 in MPEC 2017-R46 -- 6053, 3122
Q62|Sergio Foglia in Italy via iTelescope Obs. Siding Spring in New South Wales, 1 in MPEC 2017-R46 -- 1989 VB
W19Kalamazoo Obs. in Michigan, 1 in MPEC 2017-R46 -- 2014 YC15
695^Spacewatch via Kitt Peak Natl. Obs. (KPNO) in Arizona, 2 in MPEC 2017-R46 -- 2017 RL, 2017 NH
Z87Laver Obs. in England, 1 in MPEC 2017-R46 -- 6053
H01Magdalena Ridge Obs. in New Mexico, 1 in MPEC 2017-R46 -- 2012 TC4
Z80Northolt Branch Obs. in England, 1 in MPEC 2017-R46 -- 3122
J43Oukaimeden Obs. in Morocco, 2 in MPEC 2017-R46 -- 66146, 138911
G40!M. Kumrucu-Lohmiller in Massachusetts via Canary Islands Obs. in the Canary Islands, 1 in MPEC 2017-R46 -- 2017 FJ90
691Spacewatch 0.9m telescope in Arizona, 5 in MPEC 2017-R46 -- 2017 OG68, 2017 MY3, 2007 TR65, 1998 SZ27, 9202
291Spacewatch 1.8m telescope in Arizona, 3 in MPEC 2017-R46 -- 2017 RV, 2017 FJ90, 2017 FE1
V78Spirit Marsh Obs. in Minnesota, 1 in MPEC 2017-R46 -- 3122
H32Texas A&M Physics Obs. in Texas, 1 in MPEC 2017-R46 -- 3122
T14UH/Tholen NEO Follow-Up CFH Telescope in Hawaii, 1 in MPEC 2017-R45 -- 2013 AN20
718Wiggins Obs. in Utah, 1 in MPEC 2017-R46 -- 3122
For a list of all participating observatories that have Web addresses, see A/CC's Observatory Links page.

Impact Risk Monitoring  on 11 September '17

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.





Notes for Today's Latest Risk Assessments
2017 RLJPL Sentry15162072-207213.229e-08-4.34-4.340JPL: Computed at 07:48 today Pacific time based on 81 observations spanning 8.9508 days (2017-Sep-01.5615 to 2017-Sep-10.51234). Diameter approximately 0.670 km. from weighted mean H=18.52.
2008 EM68JPL Sentry15162017-211611141.35485488e-05-5.12-5.470JPL: Computed at 00:27 April 7th Pacific time based on 12 observations spanning .11019 days (2008-Mar-08.25164 to 2008-Mar-08.36183). Diameter approximately 0.010 km. from weighted mean H=27.72.

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 11 September '17

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

1712Generated Traffic Report
1516Noted that JPL Sentry has updated its 2008 EM68 risk assessment - see above
Noted that JPL Sentry has updated its 2017 RL risk assessment - see above
Grabbed MPEC 2017-R46 - Daily Orbit Update - see above
0414Grabbed MPEC 2017-R45 - 2013 AN20 - see above