Contents  on 30 May '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 30 May '17

Four objects reported inside ten LD

Four minor planets are reported within ten lunar distances (LD) of Earth today. Nearest is Moon buzzing 2017 KW31, which slides into our planet's SOI, coming in from 3.37 to 1.42 LD from us, and ends the day less than one LD from the Moon. Further out, 2017 KJ27 comes its closest to Earth on this passage -- 6.03 LD at 1549 UTC, while radar target 2017 CS moves out from 7.96 to 8.39 LD and 2017 HU49 from 8.94 to 9.22 LD.

Coming our way next, radar target 418094 2007 WV4 arrives inside ten LD tomorrow, risk-listed 2017 KQ27 enters on June 2nd, and 2017 KR27 the following day.

This report was generated at 1842 UTC with the recovery of distant and dim NHATS target 2016 UE and first follow-up for 2017 KJ27 in today's DOU MPEC, along with follow-up for 2017 KR27, 2017 KQ27, and distant 484402 2007 XH16.

The Comets Mailing List was informed today (thread) that astronomer Michael A'Hearn has died, age 76. His influential work included being the principal investigator on NASA's Deep Impact and EXPOXI comet missions.

Notes: Ten times the distance to the Moon (ten LD) has no astronomical importance but is a useful boundary for reporting on transient natural objects that approach the actually significant 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. "Moon buzzing" is used here to describe an object that passes the Moon at less than one Earth-Moon lunar distance but does not enter the Earth-Moon system during the reported passage, and "distant" describes an object that has come within ten LD since A/CC began these traffic reports ten-plus years ago, but is not currently so close. 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.

Radar Astrometry  on 30 May '17

Radar observation of one object

The JPL Solar System Dynamics Group Radar Astrometry database has added or updated the following small-body radar observing work:

Data update noted at 2300 UTC when the database was dated 30 May

NEOCP Activity  on 30 May '17

The MPC's NEO Confirmation Page has 59 listings

When last checked at 2358 UTC today, the Minor Planet Center's Near Earth Object discovery Confirmation Page (NEOCP) had 59 objects listed. Of these, 28 were "one nighters." So far The Tracking News has counted a total of 61 listings on the NEOCP today.

New MPECs  on 30 May '17

Minor Planet Electronic Circulars

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

MPEC 2017-K90 - "14:12 UT" - Comet C/2017 K2 (Panstarrs)

MPEC 2017-K89 - "14:02 UT" - Comet C/2017 F2 (Panstarrs)

<< DOU on 30 May '17 >>  MPEC 2017-K88 - "12:03 UT" - Daily Orbit Update

Observers  on 30 May '17

A total of 33 observers appear in today's MPECs.

CodeObserver / observatory
H21Astronomical Research Obs. Westfield in Illinois, 10 in MPEC 2017-K88 -- 2017 KG5, 2017 JK2, 2017 HV3, 2017 HD49, 2017 HA49, 2017 GB8, 2017 FW64, 2016 AH193, 2010 JU39, 365246
T08ATLAS Mauna Loa in Hawaii, 6 in MPEC 2017-K88 -- 2005 GL9, 475665, 136923, 4954, 1980, 1917
215Buchloe Obs. in Germany, 1 in MPEC 2017-K90 -- C/2017 K2
703Catalina Sky Survey (CSS) in Arizona, 7 in MPEC 2017-K88 -- 2017 AC5, 2016 YU8, 2005 MO13, 54789, 222073, 3103, 1917
807|Robert Holmes in Illinois via Cerro Tololo Inter-American Obs. (CTIO) in Chile, 3 in MPEC 2017-K88 -- 2017 KR27, 2017 JU2, 2017 GU6
734Farpoint Obs. in Kansas, 1 in MPEC 2017-K88 -- 2017 KJ5
157Frasso Sabino Obs. in Italy, 1 in MPEC 2017-K90 -- C/2017 K2
253Goldstone DSS-14 70m antenna in southern California, 1 in radar -- 418094
K73Gravina Obs. in Italy, 1 in MPEC 2017-K88 -- 6063
J95Great Shefford Obs. in England, 1 in MPEC 2017-K90 -- C/2017 K2
Q62|Sergio Foglia in Italy via iTelescope Obs. Siding Spring in New South Wales, 1 in MPEC 2017-K88 -- 138846
W19Kalamazoo Obs. in Michigan, 1 in MPEC 2017-K88 -- 6063
Z22MASTER IAC Obs. in the Canary Islands, 2 in MPEC 2017-K88 -- 2005 MO13, 100926
W92MASTER OAFA Obs., 2 in MPEC 2017-K88 -- 162149, 1980
K95MASTER-II Sutherland in South Africa, 1 in MPEC 2017-K88 -- 20460
568_Marco Micheli on Mauna Kea in Hawaii, 2 in MPECs 2017-K89 & 2017-K90 -- C/2017 K2, C/2017 F2
474Mt. John Obs. in New Zealand, 7 in MPEC 2017-K88 -- 2017 KV4, 2017 KQ4, 2017 KQ27, 2017 KL3, 2017 KJ5, 2017 KJ3, 2017 KF3
G96Mt. Lemmon Survey (MLS) in Arizona, 4 in MPECs 2017-K88 & 2017-K89 -- C/2017 F2, 294739, 275677, 5879
J43Oukaimeden Obs. in Morocco, 1 in MPEC 2017-K88 -- 4341
F51Pan-STARRS 1 (PS1) in Hawaii, 10 in MPEC 2017-K88 -- 2016 YU8, 2014 SR339, 2012 HN8, 2005 MO13, 89959, 454177, 339492, 241662, 171839, 5869
H45Petit Jean Mtn. South Obs. (PJMSO) in Arkansas, 19 in MPEC 2017-K88 -- 2017 KR27, 2017 HY50, 2017 HW48, 2017 HN3, 2017 GQ6, 2017 DS35, 2016 YU8, 2015 ME54, 2014 KF91, 2013 CL118, 2011 ED78, 2005 MO13, 2005 GL9, 484402, 416584, 190166, 142040, 11398, 100926
D29Purple Mtn. Obs. Xuyi Station in China, 3 in MPEC 2017-K88 -- 2017 HY50, 276468, 142040
W25RMS Obs., 1 in MPEC 2017-K88 -- 142561
L04ROASTERR-1 in Romania, 1 in MPEC 2017-K88 -- 2005 GL9
G409B. Lutkenhoner in Germany via Canary Islands Obs. in the Canary Islands, 1 in MPEC 2017-K90 -- C/2017 K2
Y00SONEAR in Brazil, 1 in MPEC 2017-K88 -- 138846
691Spacewatch 0.9m telescope in Arizona, 1 in MPEC 2017-K88 -- 2014 JG78
I52Steward Obs. Mt. Lemmon Station in Arizona, 3 in MPEC 2017-K88 -- 2017 KZ4, 2017 KK27, 2017 KA5
461SZTE Asteroid Program in Hungary, 1 in MPEC 2017-K90 -- C/2017 K2
926Tenagra II Obs. in Arizona, 5 in MPEC 2017-K88 -- 2017 KR4, 2017 KR27, 2017 KK27, 2017 KJ27, 2017 JW1
T12UH/Tholen NEO Follow-Up 2.24m Telescope in Hawaii, 2 in MPEC 2017-K88 -- 2017 GP5, 2016 UE
K41Vegaquattro Obs. in Italy, 1 in MPEC 2017-K88 -- 190166
C51WISE in Earth polar orbit, 3 in MPEC 2017-K88 -- 488450, 474179, 405427
For a list of all participating observatories that have Web addresses, see A/CC's Observatory Links page.

Impact Risk Monitoring  on 30 May '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 KQ27JPL Sentry1604R E M O V E DJPL: Risk listing removed at 1452 UTC today.
NEODyS16042092-211738.4e-07-6.73-6.780NEODyS: "Based on 17 optical observations (of which 0 are rejected as outliers) from 2017-05-25.305 to 2017-05-29.272."
2017 KB3NEODyS16042084-2117195.36e-08-7.51-7.990NEODyS: "Based on 38 optical observations (of which 0 are rejected as outliers) from 2017-05-17.219 to 2017-05-28.445."
2017 JB2JPL Sentry17302110-211014.288e-07-8.82-8.820JPL: Computed at 09:59 today Pacific time based on 28 observations spanning 19.004 days (2017-May-06.44444 to 2017-May-25.448791). Diameter approximately 0.005 km. from weighted mean H=29.04.
NEODyS16042101-211434.43e-07-8.80-8.810NEODyS: "Based on 28 optical observations (of which 1 are rejected as outliers) from 2017-05-06.445 to 2017-05-25.450."
2017 HG4NEODyS16042046-21151024.09e-05-5.81-6.380NEODyS: "Based on 34 optical observations (of which 0 are rejected as outliers) from 2017-04-26.264 to 2017-05-27.986."
2016 NL56JPL Sentry21002023-21172547.20760499999999e-07-3.67-4.510JPL: Computed at 13:56 today Pacific time based on 6 observations spanning 2.7820 days (2016-Jul-12.443828 to 2016-Jul-15.225848). Diameter approximately 0.264 km. from weighted mean H=20.61.

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 30 May '17

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

2300Noted Radar Astrometry database update - see above
2100Noted that JPL Sentry has updated its 2016 NL56 risk assessment - see above
1842Generated Traffic Report
1730Noted that JPL Sentry has updated its 2017 JB2 risk assessment - see above
1604Noted that NEODyS has updated its 2017 HG4 risk assessment - see above
Noted that NEODyS has updated its 2017 JB2 risk assessment - see above
Noted that NEODyS has updated its 2017 KB3 risk assessment - see above
Noted that JPL Sentry has removed 2017 KQ27 as an impact risk - see above
Noted that NEODyS has updated its 2017 KQ27 risk assessment - see above
Grabbed MPEC 2017-K88 - Daily Orbit Update - see above
Grabbed MPEC 2017-K89 - Comet C/2017 F2 (Panstarrs) - see above
Grabbed MPEC 2017-K90 - Comet C/2017 K2 (Panstarrs) - see above