Contents  on 16 December '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 16 December '17

Six objects reported inside ten LD

Today six minor bodies are known to be within ten lunar distances (LD) of Earth. Closest are 2006 XY, which is outbound from 3.71 to 4.29 LD, and 2017 VT14, inbound from 4.59 to 3.84 LD.

Earth passage I D ~Size Distance today  Inside ten LD Notes
3.35 LD Dec. 14 2006 XY 54 m  3.71 to 4.29 LD Dec. 5 - 23 NHATS target
3.83 LD tomorrow 2017 VT14 80 m  3.84 from 4.59 LD Dec. 13 - 21 radar target, comet nucleus?
4.51 LD yesterday 2017 XY2 13 m  4.70 to 5.51 LD Dec. 10 - 20 NHATS target, risk - DOU
5.16 LD Dec. 18 2017 XW60 8 m  5.53 from 6.51 LD Dec. 13 - 22 NEW - MPEC, DOU
6.14 LD yesterday 2017 XK1 31 m  6.41 to 7.67 LD Dec. 12 - 18
7.94 LD tomorrow 2017 XT60 11 m  8.07 from 8.50 LD Dec. 14 - 21 NEW - MPEC
Approaching (sorted by 10-LD bubble entry date)
7.61 LD Dec. 24 2017 WZ14 31 m  11.52 from 12.38 LD Dec. 18 - 30 radar/NHATS target
3.7   LD Feb. 24* 2017 DR109 10 m  158.1 from 161.2 LD Feb. 18 - March 1 EPU +/- 30 mins.*, NHATS target
3.8   LD March 7* 2017 VR12 265 m  113.6 from 115.5 LD Feb. 28 - March 13 EPU +/- 15 mins.*, radar/NHATS target
* EPU = Earth passage uncertainty

This report was generated at 1918 UTC with the discoveries announced late yesterday of two objects in the active traffic table above (2017 XW60 and 2017 XT60), and two more that have already departed. 2017 XN60 (MPEC) passed us at 8.98 LD on December 13th, and 2017 XU60 (MPEC) went by at about 3.11 LD on December 5th. Today's DOU MPEC has first follow-up for 2017 XW60 and continuing follow-up for outbound risk-listed 2017 XY2, and three departed objects: 2017 XS, 2017 VC, and intruder 2012 TC4, adding 54 days to this small and now very dim object's previous 86-day observing arc on this year's passage.



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 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 16 December '17

The MPC's NEO Confirmation Page has 56 listings

When last checked at 2357 UTC today, the Minor Planet Center's Near Earth Object discovery Confirmation Page (NEOCP) had 56 objects listed. Of these, eleven were "one nighters." So far The Tracking News has counted a total of 60 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 16 December '17

Minor Planet Electronic Circulars

As of last check at 2357 UTC, there have been six MPECs posted today from the International Astronomical Union's Minor Planet Center in Cambridge, Massachusetts.


MPEC 2017-Y06 - "16:16 UT" - 2008 TE157


<< DOU on 16 Dec. '17 >>  MPEC 2017-Y05 - "13:04 UT" - Daily Orbit Update


MPEC 2017-Y04 - "12:31 UT" - 2010 TX168


MPEC 2017-Y03 - "12:29 UT" - 2009 WZ7


MPEC 2017-Y02 - "12:26 UT" - 2015 YG


MPEC 2017-Y01 - "12:24 UT" - 2015 SY

Observers  on 16 December '17

A total of 21 observers appear in today's MPECs.

CodeObserver / observatory
H21Astronomical Research Obs. Westfield in Illinois, 20 in MPEC 2017-Y05 -- 2017 XS, 2017 WX13, 2017 WX12, 2017 WW, 2017 WV13, 2017 WU13, 2017 WG2, 2017 WG14, 2017 WF13, 2017 WD13, 2017 VU14, 2017 VO14, 2017 VC, 2017 UJ5, 2017 SE2, 2017 MN7, 53319, 475967, 21374, 7977
T08ATLAS Mauna Loa in Hawaii, 21 in MPEC 2017-Y05 -- 2014 VU1, 2014 JC31, 2007 AT2, 1999 AF4, 507366, 504887, 475967, 439908, 417201, 374851, 36284, 189173, 17511, 17182, 163696, 154555, 137062, 12711, 6053, 1864, 1580
215Buchloe Obs. in Germany, 1 in MPEC 2017-Y05 -- 3200
703Catalina Sky Survey (CSS) in Arizona, 45 in MPEC 2017-Y05 -- 2017 WX12, 2017 VU14, 2017 PS30, 2015 BF4, 2004 VC17, 1997 GC32, 96631, 88264, 87024, 68950, 53435, 53319, 53110, 506732, 505667, 505178, 504680, 497176, 483560, 444193, 438897, 415029, 333888, 294739, 27346, 25916, 248926, 210012, 162998, 162472, 162004, 154589, 142040, 140158, 136849, 136745, 11500, 100926, 9950, 8567, 8201, 7977, 5189, 1980, 1627
309&Marco Micheli via Cerro Paranal in Chile, 1 in MPEC 2017-Y05 -- 2012 TC4
807|Robert Holmes in Illinois via Cerro Tololo Inter-American Obs. (CTIO) in Chile, 2 in MPECs 2017-Y05 & 2017-Y06 -- 2017 ST20, 2008 TE157
J04ESA Optical Ground Station in the Canary Islands, 1 in MPEC 2017-Y03 -- 2009 WZ7
G48Harlingten Research Obs. in New Mexico, 1 in MPEC 2017-Y05 -- 2017 WX12
H15ISON New Mexico Obs. in New Mexico, 1 in MPEC 2017-Y05 -- 351331
G96Mt. Lemmon Survey (MLS) in Arizona, 26 in MPEC 2017-Y05 -- 2017 XH1, 2017 UW4, 2017 PL26, 2015 NW9, 2014 WG365, 2013 XS3, 2013 XF22, 2010 PM10, 2003 WX87, 88264, 499490, 497096, 444628, 438430, 27031, 252558, 228587, 22753, 202435, 194268, 164221, 164211, 153201, 4486, 4450, 2368
F51Pan-STARRS 1 in Hawaii, 1 in MPEC 2017-Y05 -- 2017 XS60
W98Polonia Obs. in Chile, 1 in MPEC 2017-Y05 -- 9950
W885M. Kumrucu-Lohmiller in Massachusetts via Slooh.com Chile Obs. in Chile, 1 in MPEC 2017-Y05 -- 504928
691Spacewatch 0.9m telescope in Arizona, 11 in MPEC 2017-Y05 -- 2017 XC1, 2017 XA2, 2017 WW12, 2017 WP12, 2017 WP1, 2017 UZ4, 2017 ME7, 2012 PN28, 2003 YX1, 499490, 16657
291Spacewatch 1.8m telescope in Arizona, 7 in MPEC 2017-Y05 -- 2017 XO2, 2017 WU, 2017 VV1, 2017 HX3, 2015 KJ57, 2014 WD201, 1994 WR12
W34Squirrel Valley Obs. in North Carolina, 1 in MPEC 2017-Y05 -- 137062
I52Steward Obs. Mt. Lemmon Station in Arizona, 10 in MPECs 2017-Y01 & 2017-Y05 -- 2017 XW2, 2017 XR2, 2017 XN2, 2017 WM15, 2017 VO15, 2017 VD14, 2015 YG, 2015 SY, 2015 BJ514, 414429
926Tenagra II Obs. in Arizona, 7 in MPECs 2017-Y01, 2017-Y02, 2017-Y03 & 2017-Y05 -- 2017 XY2, 2017 XW60, 2017 XS60, 2017 XF, 2015 YG, 2015 SY, 2009 WZ7
T14UH/Tholen NEO Follow-Up CFH Telescope in Hawaii, 1 in MPEC 2017-Y04 -- 2010 TX168
T09UH/Tholen NEO Follow-Up Subaru Telescope in Hawaii, 1 in MPEC 2017-Y04 -- 2010 TX168
C51WISE in Earth polar orbit, 6 in MPEC 2017-Y05 -- 1997 GC32, 496816, 307493, 294739, 16834, 154589
For a list of all participating observatories that have Web addresses, see A/CC's Observatory Links page.

Impact Risk Monitoring  on 16 December '17

Summary Risk Table for Risk Assessments Updated Today   (last checks: NEODyS at 2357 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.
0000NNN000

Object

Risk
Monitor
When
Noted
UTC
0000T0000
Year
Range

VI
#
000NN00
Prob
Cum
T0000
PS
Cum
T0000
PS
Max

T
S


Notes for Today's Latest Risk Assessments
2017 XY2NEODyS2329210813.04e-07-7.90-7.90NEODyS: "Based on 24 optical observations (of which 3 are rejected as outliers) from 2017-12-13.344 to 2017-12-15.332."
JPL Sentry19002109-210912.552e-10-11.00-11.00JPL: Computed at 08:45 today Pacific time based on 24 observations spanning 1.9878 days (2017-Dec-13.34308 to 2017-Dec-15.33086). Diameter approximately 0.013 km. from weighted mean H=27.09.
2017 XO2NEODyS23292022-2111513.11e-06-4.11-4.340NEODyS: "Based on 22 optical observations (of which 0 are rejected as outliers) from 2017-12-10.337 to 2017-12-16.241."
JPL Sentry19002022-21151541.52613946e-05-3.37-3.900JPL: Computed at 09:09 today Pacific time based on 22 observations spanning 5.9041 days (2017-Dec-10.33601 to 2017-Dec-16.24007). Diameter approximately 0.110 km. from weighted mean H=22.52.
2017 WE29NEODyS1600204113.18e-09-8.65-8.650NEODyS: "Based on 12 optical observations (of which 2 are rejected as outliers) from 2017-11-27.253 to 2017-11-28.435."
2017 WE28NEODyS03262035-2109566.28e-05-4.99-5.410NEODyS: "Based on 29 optical observations (of which 8 are rejected as outliers) from 2017-11-27.127 to 2017-12-11.064."
2017 WX14NEODyS0326R E M O V E D-
2017 VW13NEODyS0326209727.93e-07-4.23-4.240NEODyS: "Based on 174 optical observations (of which 6 are rejected as outliers) from 2017-11-13.641 to 2017-12-15.425."
2017 UM52NEODyS16002056-2114213.88e-05-6.75-6.840NEODyS: "Based on 8 optical observations (of which 2 are rejected as outliers) from 2017-10-27.330 to 2017-10-27.497."
2017 UK52NEODyS16002035-2117737.2e-08-8.03-8.680NEODyS: "Based on 12 optical observations (of which 1 are rejected as outliers) from 2017-10-21.249 to 2017-10-21.425."

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 16 December '17

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

2329Noted that NEODyS has updated its 2017 XO2 risk assessment - see above
Noted that NEODyS has updated its 2017 XY2 risk assessment - see above
1918Generated Traffic Report
1900Noted that JPL Sentry has updated its 2017 XO2 risk assessment - see above
Noted that JPL Sentry has updated its 2017 XY2 risk assessment - see above
1630Grabbed MPEC 2017-Y06 - 2008 TE157 - see above
1600Noted that NEODyS has posted 2017 UK52 as an impact risk - see above
Noted that NEODyS has posted 2017 UM52 as an impact risk - see above
Noted that NEODyS has posted 2017 WE29 as an impact risk - see above
Grabbed MPEC 2017-Y01 - 2015 SY - see above
Grabbed MPEC 2017-Y02 - 2015 YG - see above
Grabbed MPEC 2017-Y03 - 2009 WZ7 - see above
Grabbed MPEC 2017-Y04 - 2010 TX168 - see above
Grabbed MPEC 2017-Y05 - Daily Orbit Update - see above
0326Noted that NEODyS has updated its 2017 VW13 risk assessment - see above
Noted that NEODyS has updated its 2017 WE28 risk assessment - see above
Noted that NEODyS has removed 2017 WX14 as an impact risk - see above