Contents  on 29 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 29 December '17

Ten objects reported inside ten LD

Bulletin - 2210, updated 2359 UTC:  One new discovery of a close passer has been announced. This will be included in the next traffic report, after we obtain and process further details.

Earth passageI D~SizeInside ten LD approx.Notes
1.89 LD at 0221 Dec. 272017 YQ69 m Dec. 23 - 31MPEC


Ten asteroids are reported inside ten lunar distances (LD) of our home world today. Nearest is intruder 2017 YZ4, which started the day inside the Earth-Moon system at 0.93 LD from us and flies out to 2.90 LD.

Earth passage I D ~Size Distance today  Inside ten LD Notes
0.58 LD yesterday 2017 YZ4 9 m  0.93 to 2.90 LD Dec. 23 - Jan. 2 intruder today, NHATS target, exits Earth SOI
1.77 LD Dec. 15 2017 YD1 3 m  8.69 to 9.34 LD Nov. 30 - Dec. 31 NHATS target, risk
1.93 LD Dec. 24 2017 YS1 6 m  3.71 to 4.35 LD Dec. 11 - Jan. 7 NHATS target
2.24 LD Dec. 27 2017 YD2 6 m  4.18 to 5.84 LD Dec. 21 - Jan. 1 NHATS target, risk
2.88 LD Dec. 22 2017 YE 7 m  7.51 to 8.47 LD Dec. 13 - 31 NHATS target
4.84 LD Dec. 19 2017 YW3 17 m  7.76 to 8.29 LD Dec. 5 - Jan. 1 NHATS target
6.03 LD today 2017 YB6 10 m  6.03 LD Dec. 26 - 31 NEW, Earth closest at 0052 UTC - MPEC
7.62 LD Dec. 24 2017 WZ14 32 m  8.84 to 9.45 LD Dec. 18 - 30 radar/NHATS target
7.74 LD tomorrow 2017 YU1 20 m  7.75 from 8.05 LD Dec. 26 - Jan. 3 NHATS target
8.47 LD Dec. 25 2017 YR3 29 m  9.86 to 10.68 LD Dec. 21 - 29 NHATS target, exits ten LD
Approaching (sorted by 10-LD bubble entry date)
3.7   LD Feb. 24* 2017 DR109 10 m  118.6 from 121.5 LD Feb. 18 - March 1 EPU +/- 30 mins.*, NHATS target
3.76 LD March 7 2017 VR12 273 m  91.71 from 93.26 LD Feb. 28 - March 13 radar/NHATS target - DOU
* EPU = Earth passage uncertainty

This report was generated at 1836 UTC with the discoveries announced late yesterday of 2017 YB6 (MPEC), which today comes it closest to Earth on this passage (6.03 LD), and already departed 2017 YC6 (MPEC), which flew by at 9.61 LD on December 20th. Today's DOU MPEC has follow-up for approaching 2017 VR12, departed 2017 YH1, and distant 208023 1999 AQ10, plus astrometry from last month for 2017 WO13.



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 29 December '17

The MPC's NEO Confirmation Page has 97 listings

When last checked at 2358 UTC today, the Minor Planet Center's Near Earth Object discovery Confirmation Page (NEOCP) had 97 objects listed. Of these, 51 were "one nighters." So far The Tracking News has counted a total of 115 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 29 December '17

Minor Planet Electronic Circulars

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


MPEC 2017-Y146 - "22:04 UT" - 2017 YQ6


MPEC 2017-Y145 - "22:00 UT" - 2017 YM6


MPEC 2017-Y144 - "21:56 UT" - 2017 YP6


MPEC 2017-Y143 - "21:53 UT" - 2017 YO6


MPEC 2017-Y142 - "21:49 UT" - 2017 YN6


MPEC 2017-Y141 - "21:38 UT" - 2017 YL6


MPEC 2017-Y140 - "20:52 UT" - 2015 YT9


<< DOU on 29 Dec. '17 >>  MPEC 2017-Y139 - "13:05 UT" - Daily Orbit Update

Observers  on 29 December '17

A total of 23 observers appear in today's MPECs.

CodeObserver / observatory
H21Astronomical Research Obs. Westfield in Illinois, 15 in MPECs 2017-Y139 & 2017-Y143 -- 2017 YO6, 2017 XL1, 2017 WT13, 2017 WO13, 2017 WN13, 2017 WF2, 2017 VY1, 2017 VW13, 2017 VS12, 2017 VK2, 2017 VH1, 2017 TR4, 2017 RX15, 2017 RT1, 2014 CD13
T08ATLAS Mauna Loa in Hawaii, 1 in MPEC 2017-Y139 -- 2017 YK5
160Castelmartini Obs. in Italy, 11 in MPEC 2017-Y139 -- 2017 QL33, 53430, 504680, 21088, 17182, 16657, 154589, 137805, 11066, 3200, 1980
703Catalina Sky Survey (CSS) in Arizona, 20 in MPEC 2017-Y139 -- 2017 VR12, 2015 YR1, 1999 AF4, 96590, 507366, 439908, 36284, 337228, 307493, 302311, 208023, 177651, 138175, 137924, 137078, 12711, 111253, 6053, 1981, 1864
595Farra d'Isonzo Obs. in Italy, 1 in MPEC 2017-Y142 -- 2017 YN6
J95Great Shefford Obs. in England, 3 in MPECs 2017-Y142, 2017-Y144 & 2017-Y146 -- 2017 YQ6, 2017 YP6, 2017 YN6
C43Hoyerswerda Obs. in Germany, 1 in MPEC 2017-Y144 -- 2017 YP6
C10Maisoncelles Obs. in France, 1 in MPEC 2017-Y139 -- 2017 YE5
Z22MASTER IAC Obs. in the Canary Islands, 1 in MPEC 2017-Y139 -- 475967
568_Marco Micheli on Mauna Kea in Hawaii, 1 in MPEC 2017-Y145 -- 2017 YM6
G96Mt. Lemmon Survey (MLS) in Arizona, 2 in MPECs 2017-Y144 & 2017-Y146 -- 2017 YQ6, 2017 YP6
Z80Northolt Branch Obs. in England, 5 in MPEC 2017-Y139 -- 2017 YP5, 2017 YK5, 2017 YH1, 2017 QL33, 1999 AF4
J43Oukaimeden Obs. in Morocco, 2 in MPEC 2017-Y139 -- 349928, 174881
F51Pan-STARRS 1 (PS1) in Hawaii, 17 in MPECs 2017-Y139, 2017-Y140, 2017-Y141, 2017-Y142, 2017-Y143 & 2017-Y145 -- 2017 YO6, 2017 YN6, 2017 YM6, 2017 YL6, 2017 YC2, 2017 XC62, 2015 YT9, 2015 FO124, 2015 DP, 1997 AC11, 38091, 376729, 35432, 259802, 259221, 152563, 142348
D29Purple Mtn. Obs. Xuyi Station in China, 11 in MPEC 2017-Y139 -- 2017 QJ18, 2015 XK351, 2009 EV, 504887, 331510, 274138, 265187, 22753, 162038, 162011, 7977
K61Rokycany Obs. in the Czech Republic, 1 in MPEC 2017-Y142 -- 2017 YN6
H36Sandlot Obs. in Kansas, 4 in MPECs 2017-Y142, 2017-Y144, 2017-Y145 & 2017-Y146 -- 2017 YQ6, 2017 YP6, 2017 YN6, 2017 YM6
691Spacewatch 0.9m telescope in Arizona, 8 in MPEC 2017-Y139 -- 2017 YQ3, 2017 XF62, 2017 VX1, 2017 SS19, 2017 NU6, 2015 CV13, 2012 PN28, 216985
291Spacewatch 1.8m telescope in Arizona, 13 in MPECs 2017-Y139 & 2017-Y141 -- 2017 YZ1, 2017 YX3, 2017 YL6, 2017 YF5, 2017 YE5, 2017 XC2, 2017 XC, 2017 WP1, 2017 VX14, 2017 VS14, 2017 MB1, 2014 RX30, 2005 SQ
V78Spirit Marsh Obs. in Minnesota, 1 in MPEC 2017-Y139 -- 3122
W34Squirrel Valley Obs. in North Carolina, 1 in MPEC 2017-Y139 -- 2368
I52Steward Obs. Mt. Lemmon Station in Arizona, 8 in MPECs 2017-Y139, 2017-Y141, 2017-Y142, 2017-Y143, 2017-Y144, 2017-Y145 & 2017-Y146 -- 2017 YQ6, 2017 YP6, 2017 YO6, 2017 YN6, 2017 YM6, 2017 YL6, 2017 YB2, 2017 XP61
926Tenagra II Obs. in Arizona, 4 in MPECs 2017-Y140, 2017-Y141, 2017-Y144 & 2017-Y146 -- 2017 YQ6, 2017 YP6, 2017 YL6, 2015 YT9
For a list of all participating observatories that have Web addresses, see A/CC's Observatory Links page.

Impact Risk Monitoring  on 29 December '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.
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 YP5JPL Sentry16502070-207012.197e-08-6.64-6.640JPL: Computed at 08:28 today Pacific time based on 43 observations spanning 3.5077 days (2017-Dec-25.51022 to 2017-Dec-29.017878). Diameter approximately 0.091 km. from weighted mean H=22.86.
2017 YO5NEODyS16502060-2117271.15e-05-5.78-6.20NEODyS: "Based on 26 optical observations (of which 4 are rejected as outliers) from 2017-12-25.453 to 2017-12-28.457."
2017 YE5JPL Sentry16502078-211643.674184e-07-3.63-3.640JPL: Computed at 07:50 today Pacific time based on 27 observations spanning 8.2078 days (2017-Dec-21.00661 to 2017-Dec-29.2144). Diameter approximately 0.580 km. from weighted mean H=18.84.
2017 YZ1JPL Sentry16502047-2117469.73148870000001e-06-2.78-2.830JPL: Computed at 08:01 today Pacific time based on 30 observations spanning 8.9856 days (2017-Dec-20.42481 to 2017-Dec-29.41045). Diameter approximately 0.230 km. from weighted mean H=20.81.
NEODyS16502047-2116191.54e-05-2.58-2.640NEODyS: "Based on 27 optical observations (of which 4 are rejected as outliers) from 2017-12-20.426 to 2017-12-28.498."
2017 VW13JPL Sentry16502097-209722.4392e-06-3.75-3.800JPL: Computed at 07:52 today Pacific time based on 203 observations spanning 35.436 days (2017-Nov-13.64011 to 2017-Dec-19.076247). Diameter approximately 0.250 km. from weighted mean H=20.64.

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 29 December '17

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

2208Grabbed MPEC 2017-Y141 - 2017 YL6 - see above
Grabbed MPEC 2017-Y142 - 2017 YN6 - see above
Grabbed MPEC 2017-Y143 - 2017 YO6 - see above
Grabbed MPEC 2017-Y144 - 2017 YP6 - see above
Grabbed MPEC 2017-Y145 - 2017 YM6 - see above
Grabbed MPEC 2017-Y146 - 2017 YQ6 - see above
2107Grabbed MPEC 2017-Y140 - 2015 YT9 - see above
1836Generated Traffic Report
1650Noted that JPL Sentry has updated its 2017 VW13 risk assessment - see above
Noted that JPL Sentry has updated its 2017 YE5 risk assessment - see above
Noted that NEODyS has updated its 2017 YO5 risk assessment - see above
Noted that JPL Sentry has updated its 2017 YP5 risk assessment - see above
Noted that JPL Sentry has updated its 2017 YZ1 risk assessment - see above
Noted that NEODyS has updated its 2017 YZ1 risk assessment - see above
Grabbed MPEC 2017-Y139 - Daily Orbit Update - see above