Contents  on 20 August '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 20 August '18

Six objects reported inside ten LD

There are six visitors known to be within ten lunar distances (LD) of Earth today. Nearest is risk-listed 2018 QE, which comes its closest to our planet this time around, reaching 2.80 LD at 0317 UTC.

Neighborhood Traffic - sorted by Earth passage distance, grouped by 5.0 & 10.0 LD boundaries
Earth passage I D ~Size Distance today  Inside ten LD Notes
2.80 LD today 2018 QE 9 m  2.80 LD Aug. 10 - 29 NHATS target, Earth closest
at 0317 UTC, risk - DOU
6.21 LD Aug. 9 2018 PN22 11 m  8.52 to 8.91 LD July 25 - Aug. 23 NHATS target
7.80 LD Aug. 23 2018 PU23 8 m  7.86 from 7.91 LD Aug. 7 - Sept. 13 NHATS target, risk
7.88 LD Aug. 18 2018 PK20 23 m  8.22 to 8.92 LD Aug. 15 - 22 NHATS target
8.84 LD Aug. 18 2018 PO22 82 m  9.73 to 11.00 LD Aug. 16 - 20 exits ten LD
9.36 LD Aug. 27 2018 LQ2 37 m  9.64 from 9.72 LD Aug. 17 - Sept. 6 NHATS target
Approaching Traffic
4.22 LD Aug. 29 1998 SD9 49 m  20.45 from 22.83 LD Aug. 25 - Sept. 2 radar target

This report was generated at 1810 UTC with follow-up in today's DOU MPEC for risk-listed objects passing 2018 QE and departed 2018 PZ21, and for distant 450894 2008 BT18.

<< Reading:  JAXA has a new and improved home page for its Hayabusa2 mission, which is now at its destination, 162173 Ryugu (1999 JU3). Traveling near but not orbiting the small asteroid, a recent test maneuver brought the spacecraft to within 851 meters of the target. Decisions should be coming soon about where to take surface and subsurface samples to return to Earth, and where to deploy four small hopping rovers, including the European MASCOT rover (at CNES and DLR). DLR has news items here and here about MASCOT landing prep, and Spaceflight Now has a wrap-up report on the mission to date.

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. "Distant" is used here to describe an object that has come within ten LD since A/CC began these traffic reports (2007) but is not presently so close. 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.

NEOCP Activity  on 20 August '18

The MPC's NEO Confirmation Page has 40 listings

When last checked at 2358 UTC today, the Minor Planet Center's Near Earth Object discovery Confirmation Page (NEOCP) had 40 objects listed. Of these, sixteen were "one nighters." So far The Tracking News has counted a total of 57 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 20 August '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 20 Aug. '18 >>  MPEC 2018-Q39 - "12:04 UT" - Daily Orbit Update

Observers  on 20 August '18

Fourteen observers appear in today's MPEC.

CodeObserver / observatory
T05ATLAS Haleakala in Hawaii, 6 in MPEC 2018-Q39 -- 2018 QE, 54789, 468730, 450894, 17511, 136849
X74Campo dos Amarais Obs., 1 in MPEC 2018-Q39 -- 443923
160Castelmartini Obs. in Italy, 6 in MPEC 2018-Q39 -- 2015 OH, 86324, 438429, 283729, 18882, 719
J27El Guijo Obs. in Spain, 1 in MPEC 2018-Q39 -- 162168
K83Forti Obs., 1 in MPEC 2018-Q39 -- 13553
K74Muensterschwarzach Obs. in Germany, 4 in MPEC 2018-Q39 -- 17511, 3552, 2061, 433
I41Palomar Transient Factory (PTF) in southern California, 6 in MPEC 2018-Q39 -- 2001 SC170, 68950, 65996, 283729, 18882, 115052
F51Pan-STARRS 1 (PS1) in Hawaii, 6 in MPEC 2018-Q39 -- 2018 PX7, 2016 CE30, 2015 RE36, 2014 QE365, 369454, 250162
122Pises Obs. in France, 2 in MPEC 2018-Q39 -- 21277, 13553
679San Pedro Martir Obs. in Mexico, 2 in MPEC 2018-Q39 -- 2018 PZ21, 2018 PG21
C95SATINO-1 in France, 1 in MPEC 2018-Q39 -- 15745
G40!M. Kumrucu-Lohmiller in Massachusetts via Canary Islands Obs. in the Canary Islands, 1 in MPEC 2018-Q39 -- 2018 NN4
Y00SONEAR in Brazil, 1 in MPEC 2018-Q39 -- 6569
T12UH/Tholen NEO Follow-Up 2.24m Telescope in Hawaii, 2 in MPEC 2018-Q39 -- 2018 PA20, 2018 OA1
For a list of all participating observatories that have Web addresses, see A/CC's Observatory Links page.

Impact Risk Monitoring  on 20 August '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.





Notes for Today's Latest Risk Assessments
2018 QENEODyS20042064-2118491.25e-05-6.56-6.77n/aNEODyS: "Based on 27 optical observations (of which 1 are rejected as outliers) from 2018-08-17.430 to 2018-08-19.606."
JPL Sentry15322046-2117106.65551e-06-6.79-7.040JPL: Computed at 08:13 today Pacific time based on 27 observations spanning 2.1764 days (2018-Aug-17.42914 to 2018-Aug-19.6055). Diameter approximately 0.009 km. from weighted mean H=27.80.
2018 PZ21NEODyS20042045-2117344.69e-05-5.24-5.510NEODyS: "Based on 17 optical observations (of which 0 are rejected as outliers) from 2018-08-12.369 to 2018-08-20.159."
JPL Sentry15322045-2108254.7758713e-05-5.20-5.470JPL: Computed at 08:18 today Pacific time based on 17 observations spanning 7.7898 days (2018-Aug-12.36837 to 2018-Aug-20.158219). Diameter approximately 0.016 km. from weighted mean H=26.66.
2018 PK21JPL Sentry1707R E M O V E DJPL: Risk listing removed at 1603 UTC today
2018 PG21NEODyS20042110-211137.38e-10-6.57-6.660NEODyS: "Based on 18 optical observations (of which 0 are rejected as outliers) from 2018-08-08.552 to 2018-08-20.425."
JPL Sentry15002111-211114.385e-10-6.88-6.880JPL: Computed at 07:57 today Pacific time based on 18 observations spanning 11.873 days (2018-Aug-08.55164 to 2018-Aug-20.424275). Diameter approximately 0.470 km. from weighted mean H=19.31.
2018 PY7JPL Sentry17072097-2115121.3597588e-05-6.03-6.330JPL: Computed at 09:00 today Pacific time based on 33 observations spanning 11.926 days (2018-Aug-05.56103 to 2018-Aug-17.48666). Diameter approximately 0.015 km. from weighted mean H=26.76.
2015 ME131JPL Sentry15002019-2089993.34223e-08-3.80-4.470JPL: Computed at 11:21 April 8th of 2017 Pacific time based on 6 observations spanning 1.8406 days (2015-Jun-23.58462 to 2015-Jun-25.42522). Diameter approximately 0.499 km. from weighted mean H=19.16.

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 20 August '18

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

2004Noted that NEODyS has updated its 2018 PG21 risk assessment - see above
Noted that NEODyS has updated its 2018 PZ21 risk assessment - see above
Noted that NEODyS has updated its 2018 QE risk assessment - see above
1810Generated Traffic Report
1707Noted that JPL Sentry has removed 2018 PK21 as an impact risk - see above
Noted that JPL Sentry has updated its 2018 PY7 risk assessment - see above
1532Noted that JPL Sentry has updated its 2018 PZ21 risk assessment - see above
Noted that JPL Sentry has updated its 2018 QE risk assessment - see above
1500Noted that JPL Sentry has updated its 2015 ME131 risk assessment - see above
Noted that JPL Sentry has updated its 2018 PG21 risk assessment - see above
Grabbed MPEC 2018-Q39 - Daily Orbit Update - see above