Contents  on 7 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 7 September '17

Three objects reported inside ten LD

Three minor objects are known to be within ten lunar distances (LD) of Earth today. Nearest is intruder 2017 QB35, heading out from 3.36 to 4.21 LD.

Earth passage I D ~Size Distance Today  Notes
0.93 LD Sept. 32017 QB35 5 m  3.36 to 4.21 LD intruder
3.78 LD yesterday2017 RB 8 m  3.86 to 4.25 LD
4.36 LD Sept. 12017 QG18 12 m  8.99 to 10.29 LD exits ten LD
Approaching (sorted by 10-LD bubble entry date)
7.87 LD Sept. 291989 VB 389 m  < 10 LD Sept. 25
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 1548 UTC.

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 7 September '17

The MPC's NEO Confirmation Page has 35 listings

When last checked at 2342 UTC today, the Minor Planet Center's Near Earth Object discovery Confirmation Page (NEOCP) had 35 objects listed. Of these, 22 were "one nighters." So far The Tracking News has counted a total of 61 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 7 September '17

Minor Planet Electronic Circulars

As of last check at 2342 UTC, there have been six MPECs posted today from the International Astronomical Union's Minor Planet Center in Cambridge, Massachusetts.

<< DOU on 7 Sept. '17 >>  MPEC 2017-R41 - "12:03 UT" - Daily Orbit Update

MPEC 2017-R40 - "01:07 UT" - 2017 RV

MPEC 2017-R39 - "01:04 UT" - 2017 QY35

MPEC 2017-R38 - "01:01 UT" - 2017 RU

MPEC 2017-R37 - "00:58 UT" - 2017 RT

MPEC 2017-R36 - "00:55 UT" - 2017 RS

Observers  on 7 September '17

Seventeen observers appear in today's MPECs.

CodeObserver / observatory
H21Astronomical Research Obs. Westfield in Illinois, 5 in MPECs 2017-R36, 2017-R37, 2017-R38, 2017-R40 & 2017-R41 -- 2017 RV, 2017 RU, 2017 RT, 2017 RS, 2017 QY34
T05ATLAS Haleakala in Hawaii, 1 in MPEC 2017-R41 -- 68348
V06Catalina Sky Survey Kuiper Telescope in Arizona, 1 in MPEC 2017-R39 -- 2017 QY35
K26Contern Obs. in Luxembourg, 1 in MPEC 2017-R41 -- 3122
W46Foxfire Village Obs., 1 in MPEC 2017-R41 -- 3122
J95Great Shefford Obs. in England, 1 in MPEC 2017-R38 -- 2017 RU
Q62|Sergio Foglia in Italy via iTelescope Obs. Siding Spring in New South Wales, 1 in MPEC 2017-R41 -- 3122
695^Spacewatch via Kitt Peak Natl. Obs. (KPNO) in Arizona, 5 in MPECs 2017-R36 & 2017-R41 -- 2017 RS, 2017 RL, 2017 OP19, 2012 DP8, 2010 CP140
168Kourovskaya Obs. in Russia, 1 in MPEC 2017-R41 -- 2017 PL26
H01Magdalena Ridge Obs. (MRO) in New Mexico, 2 in MPECs 2017-R38 & 2017-R40 -- 2017 RV, 2017 RU
G96Mt. Lemmon Survey in Arizona, 1 in MPEC 2017-R40 -- 2017 RV
Z80Northolt Branch Obs. in England, 4 in MPEC 2017-R41 -- 2017 RL, 237805, 153415, 3122
F51Pan-STARRS 1 (PS1) in Hawaii, 10 in MPECs 2017-R36, 2017-R37, 2017-R38, 2017-R39, 2017-R40 & 2017-R41 -- 2017 RV, 2017 RU, 2017 RT, 2017 RS, 2017 QY35, 2017 QS17, 2015 KN120, 495857, 458368, 367525
291Spacewatch 1.8m telescope in Arizona, 2 in MPECs 2017-R36 & 2017-R37 -- 2017 RT, 2017 RS
V78Spirit Marsh Obs. in Minnesota, 1 in MPEC 2017-R41 -- 3122
T12UH/Tholen NEO Follow-Up 2.24m Telescope in Hawaii, 1 in MPEC 2017-R41 -- 2010 JM41
C51WISE in Earth polar orbit, 1 in MPEC 2017-R39 -- 2017 QY35
For a list of all participating observatories that have Web addresses, see A/CC's Observatory Links page.

Impact Risk Monitoring  on 7 September '17

Summary Risk Table for Risk Assessments Updated Today   (last checks: NEODyS at 2342 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 Sentry15422072-207215.942e-07-3.03-3.030JPL: Computed at 07:48 today Pacific time based on 55 observations spanning 5.8397 days (2017-Sep-01.5615 to 2017-Sep-07.4012). Diameter approximately 0.700 km. from weighted mean H=18.41.
NEODyS1542207211.49e-08-4.63-4.630NEODyS: "Based on 55 optical observations (of which 1 are rejected as outliers) from 2017-09-01.562 to 2017-09-07.402."
2017 PL26JPL Sentry15422087-2116174.061895e-06-4.35-4.650JPL: Computed at 07:57 today Pacific time based on 202 observations spanning 68.296 days (2017-Jun-21.52716 to 2017-Aug-28.82329). Diameter approximately 0.130 km. from weighted mean H=22.13.
NEODyS15422081-2116323.65e-06-4.38-4.570NEODyS: "Based on 205 optical observations (of which 9 are rejected as outliers) from 2017-06-21.528 to 2017-08-28.824."

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 7 September '17

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

1548Generated Traffic Report
1542Noted that JPL Sentry has updated its 2017 PL26 risk assessment - see above
Noted that NEODyS has updated its 2017 PL26 risk assessment - see above
Noted that JPL Sentry has updated its 2017 RL risk assessment - see above
Noted that NEODyS has updated its 2017 RL risk assessment - see above
Grabbed MPEC 2017-R41 - Daily Orbit Update - see above
0417Grabbed MPEC 2017-R36 - 2017 RS - see above
Grabbed MPEC 2017-R37 - 2017 RT - see above
Grabbed MPEC 2017-R38 - 2017 RU - see above
Grabbed MPEC 2017-R39 - 2017 QY35 - see above
Grabbed MPEC 2017-R40 - 2017 RV - see above