Contents  on 8 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 8 September '17

Two objects reported inside ten LD

There are two Solar-System small bodies reported traveling inside ten lunar distances (LD) of Earth today, both outbound at a similar distance. Intruder 2017 QB35 moves from 4.21 to 5.07 LD and 2017 RB from 4.25 to 4.89 LD.

Earth passage I D ~Size Distance Today  Notes
0.93 LD Sept. 32017 QB35 5 m  4.21 to 5.07 LD intruder
3.78 LD Sept. 62017 RB 8 m  4.25 to 4.89 LD
Approaching (sorted by 10-LD bubble entry date)
7.87 LD Sept. 291989 VB 389 m  < 10 LD Sept. 25 - DOU
0.13 LD Oct. 122012 TC4 15 m  < 10 LD Oct. 5, intruder, radar/NHATS target, risk
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 2014 UTC with follow-up in today's DOU MPEC for approaching 1989 VB and departed radar target 2017 CS, plus observation of 2007 DD from May 2011, adding eight days to what had been a six-minute observation arc during that year's passage at 9.30 LD.

Note:  NASA's OSIRIS-REx mission has posted an invitation for astronomers to track the spacecraft when it zooms past Earth around 10-23 September during a gravity assist maneuver to reach asteroid 101955 Bennu (1999 RQ36). See more about this on the Minor Planet Mailing List (MPML).

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 8 September '17

The MPC's NEO Confirmation Page has 52 listings

When last checked at 2202 UTC today, the Minor Planet Center's Near Earth Object discovery Confirmation Page (NEOCP) had 52 objects listed. Of these, 31 were "one nighters." So far The Tracking News has counted a total of 54 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 8 September '17

Minor Planet Electronic Circulars

As of last check at 2202 UTC, there has been one MPEC posted today from the International Astronomical Union's Minor Planet Center in Cambridge, Massachusetts.

<< DOU on 8 Sept. '17 >>  MPEC 2017-R42 - "12:03 UT" - Daily Orbit Update

Observers  on 8 September '17

Seventeen observers appear in today's MPEC.

CodeObserver / observatory
H21Astronomical Research Obs. Westfield in Illinois, 1 in MPEC 2017-R42 -- 2017 RL
160Castelmartini Obs. in Italy, 4 in MPEC 2017-R42 -- 2014 YC15, 90075, 422699, 142464
807|Robert Holmes in Illinois via Cerro Tololo Inter-American Obs. in Chile, 1 in MPEC 2017-R42 -- 2017 OC69
H06iTelescope Obs. Mayhill in New Mexico, 1 in MPEC 2017-R42 -- 2017 RL
Q62|Sergio Foglia in Italy via iTelescope Obs. Siding Spring in New South Wales, 1 in MPEC 2017-R42 -- 1989 VB
695^Spacewatch via Kitt Peak Natl. Obs. (KPNO) in Arizona, 6 in MPEC 2017-R42 -- 2017 QX1, 2017 PV26, 2017 LU, 2017 CS, 2012 EC, 2011 VQ5
J38La Vara Obs. in Spain, 1 in MPEC 2017-R42 -- 3122
568_Marco Micheli on Mauna Kea in Hawaii, 1 in MPEC 2017-R42 -- 2017 OA69
A24New Millennium Obs. in Italy, 26 in MPEC 2017-R42 -- 2016 WJ1, 2007 VM184, 495102, 477327, 467963, 452389, 433953, 378610, 378124, 345705, 326302, 275611, 225416, 203217, 152685, 152563, 138846, 12538, 7341, 5836, 5653, 5143, 3691, 3200, 1943, 1627
F51Pan-STARRS 1 (PS1) in Hawaii, 4 in MPEC 2017-R42 -- 2017 OC69, 2017 OA69, 2014 SR339, 265196
645Sloan Digital Sky Survey in New Mexico, 1 in MPEC 2017-R42 -- 2006 BY8
G40!M. Kumrucu-Lohmiller in Massachusetts via Canary Islands Obs. in the Canary Islands, 1 in MPEC 2017-R42 -- 1998 SZ27
Y00SONEAR in Brazil, 1 in MPEC 2017-R42 -- 3752
V78Spirit Marsh Obs. in Minnesota, 1 in MPEC 2017-R42 -- 3122
T12UH/Tholen NEO Follow-Up 2.24m Telescope in Hawaii, 1 in MPEC 2017-R42 -- 2007 DD
T14UH/Tholen NEO Follow-Up CFH Telescope in Hawaii, 1 in MPEC 2017-R42 -- 2017 OA69
C51WISE in Earth polar orbit, 2 in MPEC 2017-R42 -- 2017 QC36, 2017 OD69
For a list of all participating observatories that have Web addresses, see A/CC's Observatory Links page.

Impact Risk Monitoring  on 8 September '17

Summary Risk Table for Risk Assessments Updated Today   (last checks: NEODyS at 2202 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 RLNEODyS2202207211.6e-08-4.62-4.620NEODyS: "Based on 63 optical observations (of which 1 are rejected as outliers) from 2017-09-01.562 to 2017-09-07.402."
JPL Sentry15492072-207217.719e-07-2.94-2.940JPL: Computed at 07:51 today Pacific time based on 63 observations spanning 5.8397 days (2017-Sep-01.5615 to 2017-Sep-07.4012). Diameter approximately 0.690 km. from weighted mean H=18.46.
2017 QC36NEODyS22022024-2087147.63e-10-5.60-5.880NEODyS: "Based on 7 optical observations (of which 0 are rejected as outliers) from 2017-08-18.601 to 2017-08-19.060."
JPL Sentry17022024-2117795.010493e-07-5.27-5.610JPL: Computed at 09:49 today Pacific time based on 7 observations spanning .45854 days (2017-Aug-18.60031 to 2017-Aug-19.05885). Diameter approximately 0.081 km. from weighted mean H=23.15.
2017 PV26NEODyS1549R E M O V E D-
2017 OD69NEODyS22022042-2107101.32e-09-6.46-7.080NEODyS: "Based on 12 optical observations (of which 0 are rejected as outliers) from 2017-07-30.961 to 2017-08-02.907."
JPL Sentry15492051-211653.1913e-09-6.01-6.310JPL: Computed at 08:10 today Pacific time based on 12 observations spanning 2.9462 days (2017-Jul-30.95984 to 2017-Aug-02.90605). Diameter approximately 0.336 km. from weighted mean H=20.19.

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 8 September '17

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

2202Noted that NEODyS has posted 2017 OD69 as an impact risk - see above
Noted that NEODyS has posted 2017 QC36 as an impact risk - see above
Noted that NEODyS has updated its 2017 RL risk assessment - see above
2014Generated Traffic Report
1702Noted that JPL Sentry has posted 2017 QC36 as an impact risk - see above
1549Noted that JPL Sentry has posted 2017 OD69 as an impact risk - see above
Noted that NEODyS has removed 2017 PV26 as an impact risk - see above
Noted that JPL Sentry has updated its 2017 RL risk assessment - see above
Grabbed MPEC 2017-R42 - Daily Orbit Update - see above