Contents  on 6 October '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 6 October '17

Four objects reported inside ten LD

Today four visitors are reported within ten lunar distances (LD) of our home world. Nearest is new discovery 2017 TB, which is inside Earth's SOI (sphere of gravitational influence), moving away from 1.16 to 1.94 LD. And newly announced 2017 TA comes its closest to Earth this time around, reaching 2.66 LD at 2131 UTC.

Earth passage I D ~Size Distance Today  Notes
0.13 LD Oct. 122012 TC4 15 m  7.78 from 9.26 LD intruder, radar/NHATS target, risk
0.23 LD Oct. 22017 SX17 8 m  5.42 to 6.93 LD intruder
1.14 LD yesterday2017 TB 5 m  1.16 to 1.94 LD NEW, inside Earth SOI - MPEC
2.66 LD today2017 TA 37 m  2.66 LD NEW, Earth closest at 2131 UTC - MPEC
Approaching (sorted by 10-LD bubble entry date)
8.94 LD Oct. 112017 SB20 36 m  < 10 LD Oct. 8
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
8.66 LD Nov. 17444584 2006 UK 309 m  < 10 LD Nov. 16

This report was generated at 1820 UTC with discoveries 2017 TB (MPEC) and 2017 TA (MPEC), and with astrometry in today's DOU MPEC for departed risk-listed objects 2017 SF20 and 2017 RV2.

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 6 October '17

The MPC's NEO Confirmation Page has 61 listings

When last checked at 2323 UTC today, the Minor Planet Center's Near Earth Object discovery Confirmation Page (NEOCP) had 61 objects listed. Of these, thirteen were "one nighters." So far The Tracking News has counted a total of 96 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 October '17

Minor Planet Electronic Circulars

As of last check at 2323 UTC, there have been three MPECs posted today from the International Astronomical Union's Minor Planet Center in Cambridge, Massachusetts.

MPEC 2017-T19 - "16:22 UT" - 2017 TB

MPEC 2017-T18 - "16:18 UT" - 2017 TA

<< DOU on 6 Oct. '17 >>  MPEC 2017-T17 - "12:15 UT" - Daily Orbit Update

Observers  on 6 October '17

Ten observers appear in today's MPECs.

CodeObserver / observatory
160Castelmartini Obs. in Italy, 10 in MPECs 2017-T17 & 2017-T18 -- 2017 TA, 2017 PJ26, 2017 OP68, 2014 YC15, 2004 RE84, 411201, 333888, 143624, 142464, 11500
J95Great Shefford Obs. in England, 1 in MPEC 2017-T18 -- 2017 TA
H01Magdalena Ridge Obs. (MRO) in New Mexico, 2 in MPECs 2017-T18 & 2017-T19 -- 2017 TB, 2017 TA
G96Mt. Lemmon Survey (MLS) in Arizona, 2 in MPECs 2017-T18 & 2017-T19 -- 2017 TB, 2017 TA
Z80Northolt Branch Obs. in England, 1 in MPEC 2017-T18 -- 2017 TA
557Ondrejov Obs. in the Czech Republic, 1 in MPEC 2017-T17 -- 65679
F51Pan-STARRS 1 (PS1) in Hawaii, 2 in MPEC 2017-T17 -- 2017 SF20, 2017 RV2
104San Marcello Pistoiese Obs. in Italy, 1 in MPEC 2017-T18 -- 2017 TA
926Tenagra II Obs. in Arizona, 3 in MPECs 2017-T17, 2017-T18 & 2017-T19 -- 2017 TB, 2017 TA, 2017 ST14
C51WISE in Earth polar orbit, 4 in MPEC 2017-T17 -- 2017 NU6, 2014 SR339, 68950, 3122
For a list of all participating observatories that have Web addresses, see A/CC's Observatory Links page.

Impact Risk Monitoring  on 6 October '17

Summary Risk Table for Risk Assessments Updated Today   (last checks: NEODyS at 2323 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 TBJPL Sentry18302054-2117545.06149892e-05-6.61-7.220JPL: Computed at 11:20 today Pacific time based on 30 observations spanning 2.1484 days (2017-Oct-03.33674 to 2017-Oct-05.48518). Diameter approximately 0.005 km. from weighted mean H=29.13.
2017 SF20NEODyS16002034-203634.27e-04-4.53-4.530NEODyS: "Based on 26 optical observations (of which 2 are rejected as outliers) from 2017-09-28.368 to 2017-10-01.356."
JPL Sentry15352034-203412.674e-04-4.74-4.740JPL: Computed at 07:51 today Pacific time based on 26 observations spanning 2.9882 days (2017-Sep-28.36701 to 2017-Oct-01.35517). Diameter approximately 0.007 km. from weighted mean H=28.32.
2017 RV2NEODyS16002071-2117394.95e-05-5.27-5.780NEODyS: "Based on 131 optical observations (of which 10 are rejected as outliers) from 2017-09-14.436 to 2017-09-27.493."
JPL Sentry15352071-2117410.000105661304-4.94-5.720JPL: Computed at 08:02 today Pacific time based on 131 observations spanning 13.057 days (2017-Sep-14.43497 to 2017-Sep-27.49213). Diameter approximately 0.019 km. from weighted mean H=26.21.

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 October '17

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

1830Noted that JPL Sentry has posted 2017 TB as an impact risk - see above
1820Generated Traffic Report
1700Grabbed MPEC 2017-T18 - 2017 TA - see above
Grabbed MPEC 2017-T19 - 2017 TB - see above
1600Noted that NEODyS has updated its 2017 RV2 risk assessment - see above
Noted that NEODyS has updated its 2017 SF20 risk assessment - see above
1535Noted that JPL Sentry has updated its 2017 RV2 risk assessment - see above
Noted that JPL Sentry has updated its 2017 SF20 risk assessment - see above
Grabbed MPEC 2017-T17 - Daily Orbit Update - see above