Contents  on 7 January '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 7 January '18

One object reported inside ten LD

Today we know of just one planetesimal within ten lunar distances (LD) of Earth, and that object, 2017 YS1, leaves the ten-LD "bubble," moving out from 9.86 to 10.56 LD.

Earth passage I D ~Size Distance today  Inside ten LD Notes
1.93 LD Dec. 24 2017 YS1 6 m  9.86 to 10.56 LD Dec. 11 - today NHATS target, exits ten LD
Approaching (sorted by 10-LD bubble entry date)
4.6   LD Jan. 23* 2018 AJ 39 m  20.0 from 21.3 LD Jan. 16 - 30 NEW, EPU +/- 1.90 hours* - MPEC
3.7   LD Feb. 24* 2017 DR109 10 m  93.8 from 96.5 LD Feb. 18 - March 1 EPU +/- 30 mins.*, NHATS target
3.76 LD March 7 2017 VR12 272 m  78.56 from 79.96 LD Feb. 28 - March 13 radar/NHATS target
* EPU = Earth passage uncertainty

This report was generated at 2040 UTC with the discoveries announced late yesterday of approaching 2018 AJ (MPEC) and departed intruder 2018 AH (MPEC, DOU), which flew by us at 0.77 LD, and the Moon at 1.42&nbs;LD, on January 2nd. Today's DOU MPEC has follow-up for distant 208023 1999 AQ10 and carries discovery announcements for six objects that, for the lack of observation, didn't make it out of the NEO confirmation process in December, including three now departed close passers that are all risk listed. Intruder 2017 WE30 snuck past our planet at 0.078 LD, and the Moon at 1.04 LD, on November 26th. 2017 YV8 went by at about 2.5 LD on December 17th (passage uncertainty +/- 5.67 hours). And 2017 WF30 may have gone by at 2.1 LD on December 6th, but JPL hasn't assigned an uncertainty, which indicates plus-or-minus more than ten days.

Reading:  Spaceflight Now has a nice wrap-up on what's literally ahead for the New Horizons extended mission out in the Kuiper Belt.

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 now 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 7 January '18

The MPC's NEO Confirmation Page has 33 listings

When last checked at 2358 UTC today, the Minor Planet Center's Near Earth Object discovery Confirmation Page (NEOCP) had 33 objects listed. Of these, eleven were "one nighters." So far The Tracking News has counted a total of 34 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 January '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 7 Jan. '18 >>  MPEC 2018-A25 - "13:03 UT" - Daily Orbit Update

Observers  on 7 January '18

Seventeen observers appear in today's MPEC.

CodeObserver / observatory
H21Astronomical Research Obs. Westfield in Illinois, 4 in MPEC 2018-A25 -- 2017 XC1, 2017 VK2, 2010 FH81, 20086
T05ATLAS Haleakala in Hawaii, 2 in MPEC 2018-A25 -- 2017 YP4, 2017 YD8
T08ATLAS Mauna Loa in Hawaii, 15 in MPEC 2018-A25 -- 2017 YR1, 496818, 385580, 361071, 333888, 276703, 164121, 162998, 142040, 100926, 8567, 6050, 2202, 1980, 1627
160Castelmartini Obs. in Italy, 8 in MPEC 2018-A25 -- 96590, 85628, 294739, 152931, 11066, 1980, 1866, 1627
703Catalina Sky Survey (CSS) in Arizona, 19 in MPEC 2018-A25 -- 2017 XT61, 2014 VM, 2007 AG, 53430, 506859, 438897, 333888, 220839, 162998, 154589, 153349, 141498, 138013, 136923, 100926, 8567, 8037, 7977, 2202
G48Harlingten Research Obs. in New Mexico, 1 in MPEC 2018-A25 -- 2017 YP4
Q62`Steven M. Tilley in Louisiana via iTelescope Obs. Siding Spring in New South Wales, 1 in MPEC 2018-A25 -- 2017 XD
P93JAXA Space Tracking & Communications Center in Japan, 1 in MPEC 2018-A25 -- 2017 YP4
Z87Laver Obs. in England, 1 in MPEC 2018-A25 -- 3122
568_Marco Micheli on Mauna Kea in Hawaii, 2 in MPEC 2018-A25 -- 2017 YX8, 2017 YU8
G96Mt. Lemmon Survey (MLS) in Arizona, 18 in MPEC 2018-A25 -- 2017 YV8, 2017 XR60, 2017 XO60, 2017 WF30, 2017 WE30, 2015 YR1, 2011 BM24, 2007 AT2, 504025, 36284, 302311, 225586, 208023, 177255, 152942, 138175, 137078, 1864
Z80Northolt Branch Obs. in England, 1 in MPEC 2018-A25 -- 2018 AH
F51Pan-STARRS 1 (PS1) in Hawaii, 17 in MPEC 2018-A25 -- 2017 YX8, 2017 YW8, 2017 YU8, 2017 TX3, 2015 YR1, 2014 WG365, 65690, 495891, 456536, 374851, 351278, 334673, 281365, 21374, 203015, 177651, 155110
291Spacewatch 1.8m telescope in Arizona, 1 in MPEC 2018-A25 -- 2017 YX8
W34Squirrel Valley Obs. in North Carolina, 2 in MPEC 2018-A25 -- 16657, 11066
I52Steward Obs. Mt. Lemmon Station in Arizona, 2 in MPEC 2018-A25 -- 2017 YX8, 2017 YV8
926Tenagra II Obs. in Arizona, 1 in MPEC 2018-A25 -- 2017 YG7
For a list of all participating observatories that have Web addresses, see A/CC's Observatory Links page.

Impact Risk Monitoring  on 7 January '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
2017 YV8JPL Sentry17102044-21171242.73750666e-05-5.89-6.620JPL: Computed at 09:00 today Pacific time based on 12 observations spanning .95148 days (2017-Dec-25.19157 to 2017-Dec-26.14305). Diameter approximately 0.012 km. from weighted mean H=27.33.
2017 WF30JPL Sentry20072019-21179711.9532499e-06-6.19-7.390JPL: Computed at 10:34 today Pacific time based on 8 observations spanning .17008 days (2017-Nov-28.27313 to 2017-Nov-28.44321). Diameter approximately 0.018 km. from weighted mean H=26.42.
2017 WE30JPL Sentry16202038-209481.043416e-07-9.88-10.10JPL: Computed at 08:00 today Pacific time based on 13 observations spanning .20925 days (2017-Nov-26.26559 to 2017-Nov-26.47484). Diameter approximately 0.001 km. from weighted mean H=31.87.
2005 NX55JPL Sentry16202019-21071064.46032e-08-4.88-5.510JPL: Computed at 13:16 April 9th of 2017 Pacific time based on 14 observations spanning 1.1343 days (2005-Jul-11.16281 to 2005-Jul-12.297115). Diameter approximately 0.141 km. from weighted mean H=21.87.

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 January '18

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

2040Generated Traffic Report
2007Noted that JPL Sentry has posted 2017 WF30 as an impact risk - see above
1710Noted that JPL Sentry has posted 2017 YV8 as an impact risk - see above
1620Noted that JPL Sentry has updated its 2005 NX55 risk assessment - see above
Noted that JPL Sentry has posted 2017 WE30 as an impact risk - see above
Grabbed MPEC 2018-A25 - Daily Orbit Update - see above