Contents  on 7 February '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 February '17

Nine objects reported inside ten LD

There are nine transient natural objects known to be traveling inside ten lunar distances (LD) of our home world today. Nearest is NHATS target 2017 BG30, which is outbound from 2.69 to 3.04 LD. Much more distant, 2017 BQ6 comes its closest to Earth on this passage -- 6.56 LD at 0635 UTC, and two objects leave our ten-LD traffic reporting zone: NHATS target 2017 BJ30 slips away from 9.00 to 10.29 LD and 2017 BN92 from 9.02 to 10.25 LD.

Earth passage I D ~Size Distance Today  Notes
1.03 LD Jan. 312017 BJ30 16 m  9.00 to 10.29 LD exits ten LD, NHATS target
2.48 LD Feb. 52017 BG30 4 m  2.69 to 3.04 LD NHATS target
3.36 LD tomorrow2017 BM93 16 m  3.94 from 5.57 LD
3.56 LD Feb. 42017 CX1 8 m  4.23 to 4.82 LD
4.27 LD yesterday2017 CR 17 m  5.37 to 8.30 LD
4.84 LD Feb. 12017 BN92 25 m  9.02 to 10.25 LD exits ten LD - DOU
6.56 LD today2017 BQ6 177 m  6.56 LD Earth closest at 0635 UTC - DOU
7.10 LD Feb. 52013 FK 78 m  7.52 to 8.38 LD
8.64 LD Feb. 52017 BK30 12 m  9.01 to 9.92 LD risk

This report was generated at 2041 UTC with first follow-up for departed risk-listed 2017 AP4 (21.15 days added to 6.64-day discovery arc) in today's DOU MPEC, along with continuing follow-up for passing 2017 BQ6, outbound 2017 BN92, departed 2017 AP19, and three approaching objects: radar/NHATS target 2017 BW and risk-listed 2017 CS and 2017 BY93.

Approaching (sorted by 10-LD bubble entry date)
4.64 LD Feb. 172017 BW 70 m  < 10 LD Feb. 9, radar/NHATS target - DOU
3.6   LD Feb. 242017 CP1 41 m  < 10 LD Feb. 15, uncertainty +/- 2.7833 hours, NHATS target
2.4   LD Feb. 232017 BY93 81 m  < 10 LD Feb. 21, uncertainty +/- 1.0000 hours, risk - DOU
2.7   LD March 22012 DR32 41 m  < 10 LD Feb. 28, uncertainty +/- 4.1333 hours
8.34 LD March 161998 SL36 309 m  < 10 LD March 14
7.63 LD March 262015 TC25 4 m  < 10 LD March 17, radar/NHATS target, risk
4.57 LD April 192014 JO25 812 m  < 10 LD April 18
8.1   LD May 292017 CS 453 m  < 10 LD May 26, uncertainty +/- 2.2833 hours, risk - DOU

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. 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 February '17

The MPC's NEO Confirmation Page has 73 listings

When last checked at 2358 UTC today, the Minor Planet Center's Near Earth Object discovery Confirmation Page (NEOCP) had 73 objects listed. Of these, 36 were "one nighters." So far The Tracking News has counted a total of 79 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 February '17

Minor Planet Electronic Circulars

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

MPEC 2017-C71 - "16:54 UT" - Comet 45P/Honda-Mrkos-Pajdusakova

<< DOU on 7 Feb. '17 >>  MPEC 2017-C70 - "13:05 UT" - Daily Orbit Update

Observers  on 7 February '17

A total of 28 observers appear in today's MPECs.

CodeObserver / observatory
349Ageo Obs. in Japan, 1 in MPEC 2017-C71 -- 45P
H21Astronomical Research Obs. Westfield in Illinois, 13 in MPEC 2017-C70 -- 2017 BW32, 2017 BW, 2017 BR93, 2017 BN31, 2017 BL3, 2017 BK92, 2017 BF30, 2017 AP19, 2014 YQ15, 2013 FY7, 2004 SW55, 2002 WQ, 1998 TT3
B96Brixiis Obs. in Belgium, 1 in MPEC 2017-C71 -- 45P
W96Campo Catino Austral Obs. in Chile, 1 in MPEC 2017-C71 -- 45P
G36CASADO in Spain, 3 in MPEC 2017-C70 -- 42286, 226198, 3691
160Castelmartini Obs. in Italy, 3 in MPECs 2017-C70 & 2017-C71 -- 3200, 1943, 45P
807|Robert Holmes in Illinois via Cerro Tololo Inter-American Obs. in Chile, 1 in MPEC 2017-C70 -- 2017 BP3
Z45Cosmos Obs., 2 in MPEC 2017-C70 -- 2017 BW, 40267
Q60ISON Siding Spring Obs. in New South Wales, 1 in MPEC 2017-C70 -- 4957
D95Kurihara Obs. in Japan, 1 in MPEC 2017-C71 -- 45P
950.Ovidiu Vaduvescu via La Palma in the Canary Islands, 3 in MPEC 2017-C70 -- 2011 GO27, 2010 OC127, 429584
W86LCOGT Cerro Tololo B in Chile, 1 in MPEC 2017-C70 -- 2005 QB5
Z21LCOGT Tenerife Aqawan A#1 in the Canary Islands, 1 in MPEC 2017-C70 -- 2017 CH1
Q19Machida Obs. in Japan, 1 in MPEC 2017-C71 -- 45P
G96Mt. Lemmon Survey (MLS) in Arizona, 8 in MPEC 2017-C70 -- 2017 CQ, 2017 BU93, 2015 BO509, 2014 BG3, 2006 DX, 23606, 152679, 11398
K74Muensterschwarzach Obs. in Germany, 1 in MPEC 2017-C71 -- 45P
J69North Obs. in England, 3 in MPEC 2017-C70 -- 2017 BW, 2017 BQ6, 2017 BN92
J43Oukaimeden Obs. in Morocco, 2 in MPEC 2017-C70 -- 13651, 5693
F51Pan-STARRS 1 (PS1) in Hawaii, 4 in MPEC 2017-C70 -- 2016 AY193, 2014 NZ64, 326683, 310442
D29Purple Mtn. Obs. Xuyi Station in China, 2 in MPEC 2017-C70 -- 203471, 11398
W25RMS Obs., 4 in MPEC 2017-C70 -- 2017 BQ6, 2017 BM3, 2017 BL3, 85990
Q11Shinshiro Obs., 1 in MPEC 2017-C71 -- 45P
G40!M. Kumrucu-Lohmiller in Massachusetts via Canary Islands Obs. in the Canary Islands, 1 in MPEC 2017-C70 -- 2017 BL30
G40%program code "%" (14) via Canary Islands Obs. in the Canary Islands, 1 in MPEC 2017-C70 -- 163693
G409B. Lutkenhoner in Germany via Canary Islands Obs. in the Canary Islands, 1 in MPEC 2017-C71 -- 45P
291Spacewatch 1.8m telescope in Arizona, 3 in MPEC 2017-C70 -- 2017 CS, 2017 BY93, 2017 BD29
J22Tacande Obs. in the Canary Islands, 1 in MPEC 2017-C71 -- 45P
I81Tarbatness Obs. in Scotland, 1 in MPEC 2017-C71 -- 45P
T12UH/Tholen NEO Follow-Up 2.24m Telescope in Hawaii, 2 in MPEC 2017-C70 -- 2017 BF30, 2017 AP4
C51WISE in Earth polar orbit, 3 in MPEC 2017-C70 -- 2017 AQ19, 54789, 137158
For a list of all participating observatories that have Web addresses, see A/CC's Observatory Links page.

Impact Risk Monitoring  on 7 February '17

Summary Risk Table for Risk Assessments Updated Today   (last checks: NEODyS and JPL 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 JPL NEO Program Sentry and NEODyS CLOMON2 risk pages.





Notes for Today's Latest Risk Assessments
2017 CH1JPL Sentry17052037-209581.0e-06-2.50-2.880JPL: "Analysis based on 38 observations spanning 21.592 days (2017-Jan-15.64059 to 2017-Feb-06.232093)." Diameter approximately 0.903 km. from mean, weighted H=17.9.
2017 BY93JPL Sentry17352046-2064102.1e-06-4.45-4.560JPL: "Analysis based on 23 observations spanning 11.819 days (2017-Jan-26.49954 to 2017-Feb-07.31837)." Diameter approximately 0.081 km. from mean, weighted H=23.1.
2017 BL30JPL Sentry17052029-205279.8e-04-1.76-1.761JPL: "Analysis based on 105 observations spanning 8.7000 days (2017-Jan-28.37792 to 2017-Feb-06.07791)." Diameter approximately 0.072 km. from mean, weighted H=23.4.
NEODyS17052029-2098261.03e-03-1.73-1.731NEODyS: "Based on 105 optical observations (of which 0 are rejected as outliers) from 2017-01-28.379 to 2017-02-06.079."
2016 AY193NEODyS1705R E M O V E D-
JPL Sentry1705R E M O V E DJPL: Risk listing removed at 1602 UTC.
2014 NZ64NEODyS1705R E M O V E D-
JPL Sentry1705R E M O V E DJPL: Risk listing removed at 1614 UTC.

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 February '17

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

2041Generated Traffic Report
1735Noted that JPL Sentry has updated its 2017 BY93 risk assessment - see above
1705Noted that JPL Sentry has removed 2014 NZ64 as an impact risk - see above
Noted that NEODyS has removed 2014 NZ64 as an impact risk - see above
Noted that JPL Sentry has removed 2016 AY193 as an impact risk - see above
Noted that NEODyS has removed 2016 AY193 as an impact risk - see above
Noted that JPL Sentry has updated its 2017 BL30 risk assessment - see above
Noted that NEODyS has updated its 2017 BL30 risk assessment - see above
Noted that JPL Sentry has updated its 2017 CH1 risk assessment - see above
Grabbed MPEC 2017-C70 - Daily Orbit Update - see above
Grabbed MPEC 2017-C71 - Comet 45P/Honda-Mrkos-Pajdusakova - see above