Contents  on 5 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 5 December '17

Six objects reported inside ten LD

Today six planetesimals are reported traveling through the space within a radius of ten lunar distances (LD) from our home world. Nearest of these is 2008 WM61, moving away from 4.51 to 5.19 LD. Much further out, newly announced risk-listed 2017 WT28 exits ten LD, passing from 9.62 to 10.61 LD, while two others enter the space. Returninng 2006 XY comes in from 10.89 to 9.86 LD and 2017 WV12 from 12.18 to 9.91 LD.

Earth passage I D ~Size Distance Today  Notes
1.39 LD Nov. 252017 WT28 8 m  9.62 to 10.61 LD NEW, NHATS target, exits ten LD, risk - MPEC
3.35 LD Dec. 142006 XY 54 m  9.86 from 10.89 LD NHATS target, enters ten LD
3.43 LD Dec. 92017 WV12 25 m  9.91 from 12.18 LD enters ten LD - DOU
3.67 LD Dec. 22008 WM61 15 m  4.51 to 5.19 LD NHATS target
3.72 LD Nov. 292017 WF16 6 m  6.56 to 7.34 LD NHATS target
9.45 LD today2017 WS13 40 m  9.45 LD Earth closest at 1336 UTC
Approaching (sorted by 10-LD bubble entry date)
9.71 LD Dec. 142015 XX169 11 m  NHATS target
3.8   LD Dec. 172017 VT14 100 m  Earth passage uncertainty +/- 40 mins., radar target, risk, comet nucleus?
7.6   LD Dec. 242017 WZ14 31 m  Earth passage uncertainty +/- 54 mins., radar/NHATS target
3.7   LD Feb. 242017 DR109 10 m  Earth passage uncertainty +/- 30 mins., NHATS target
3.7   LD March 72017 VR12 268 m  Earth passage uncertainty +/- 1.27 hours, radar/NHATS target

This report was generated at 1820 UTC with the discovery of 2017 WT28 (MPEC) and with follow-up in today's DOU MPEC for 2017 WV12.

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 5 December '17

The MPC's NEO Confirmation Page has 30 listings

When last checked at 2358 UTC today, the Minor Planet Center's Near Earth Object discovery Confirmation Page (NEOCP) had 30 objects listed. Of these, eight were "one nighters." So far The Tracking News has counted a total of 38 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 5 December '17

Minor Planet Electronic Circulars

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

<< DOU on 5 Dec. '17 >>  MPEC 2017-X14 - "13:11 UT" - Daily Orbit Update

MPEC 2017-X13 - "04:20 UT" - 2017 WT28

MPEC 2017-X12 - "04:18 UT" - 2017 WS28

MPEC 2017-X11 - "04:15 UT" - 2017 WR28

Observers  on 5 December '17

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

CodeObserver / observatory
H21Astronomical Research Obs. Westfield in Illinois, 16 in MPECs 2017-X11, 2017-X12 & 2017-X14 -- 2017 WS28, 2017 WR28, 2017 VX14, 2017 UZ42, 2017 UR7, 2014 YC15, 2014 VM, 2004 VC17, 1999 AF4, 504680, 374851, 333888, 17182, 16657, 154589, 1980
T05ATLAS Haleakala in Hawaii, 6 in MPEC 2017-X14 -- 17511, 17182, 163696, 137062, 12711, 6053
T08ATLAS Mauna Loa in Hawaii, 5 in MPEC 2017-X14 -- 99907, 496818, 6050, 2329, 1036
160Castelmartini Obs. in Italy, 10 in MPECs 2017-X11 & 2017-X14 -- 2017 WR28, 96590, 505667, 415029, 190208, 162011, 8567, 3200, 2368, 1864
703Catalina Sky Survey (CSS) in Arizona, 2 in MPECs 2017-X11 & 2017-X13 -- 2017 WT28, 2017 WR28
V06Catalina Sky Survey Kuiper Telescope (CSS-Kuiper) in Arizona, 2 in MPECs 2017-X11 & 2017-X12 -- 2017 WS28, 2017 WR28
K51Celado Obs. in Italy, 1 in MPEC 2017-X11 -- 2017 WR28
807|Robert Holmes in Illinois via Cerro Tololo Inter-American Obs. (CTIO) in Chile, 5 in MPECs 2017-X11, 2017-X12, 2017-X13 & 2017-X14 -- 2017 WT28, 2017 WS28, 2017 WR28, 2017 TS3, 2017 QL33
850Cordell-Lorenz Obs. in Tennessee, 1 in MPEC 2017-X11 -- 2017 WR28
J27El Guijo Obs. in Spain, 2 in MPEC 2017-X14 -- 163696, 137062
595Farra d'Isonzo Obs. in Italy, 1 in MPEC 2017-X11 -- 2017 WR28
203GiaGa Obs. in Italy, 4 in MPECs 2017-X11 & 2017-X14 -- 2017 WV13, 2017 WV12, 2017 WR28, 2017 WL1
K88GINOP-KHK in Hungary, 1 in MPEC 2017-X11 -- 2017 WR28
T03LCO Haleakala Clamshell#3 in Hawaii, 1 in MPEC 2017-X14 -- 3200
H01Magdalena Ridge Obs. (MRO) in New Mexico, 2 in MPECs 2017-X11 & 2017-X12 -- 2017 WS28, 2017 WR28
G96Mt. Lemmon Survey in Arizona, 1 in MPEC 2017-X12 -- 2017 WS28
F51Pan-STARRS 1 (PS1) in Hawaii, 5 in MPEC 2017-X14 -- 2015 UK52, 501934, 444193, 403039, 159467
G403Tony Evans in Portugal via Canary Islands Obs. in the Canary Islands, 1 in MPEC 2017-X14 -- 2017 WV13
345Sobaeksan Obs. in South Korea, 1 in MPEC 2017-X14 -- 2017 VW13
587Sormano Obs. in Italy, 1 in MPEC 2017-X11 -- 2017 WR28
I52Steward Obs. Mt. Lemmon Station in Arizona, 2 in MPECs 2017-X11 & 2017-X13 -- 2017 WT28, 2017 WR28
T12UH/Tholen NEO Follow-Up 2.24m Telescope in Hawaii, 1 in MPEC 2017-X14 -- 451370
C51WISE in Earth polar orbit, 4 in MPEC 2017-X14 -- 411201, 337228, 162998, 1865
For a list of all participating observatories that have Web addresses, see A/CC's Observatory Links page.

Impact Risk Monitoring  on 5 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.





Notes for Today's Latest Risk Assessments
2017 WT28JPL Sentry15302081-2117580.004134388216-4.30-4.390JPL: Computed at 22:22 Dec. 4th Pacific time based on 17 observations spanning 4.8457 days (2017-Nov-28.29053 to 2017-Dec-03.13623). Diameter approximately 0.008 km. from weighted mean H=28.06.
2017 VW13JPL Sentry16002097-209712.348e-07-4.76-4.760JPL: Computed at 07:51 today Pacific time based on 141 observations spanning 17.166 days (2017-Nov-13.64011 to 2017-Nov-30.80635). Diameter approximately 0.260 km. from weighted mean H=20.62.
NEODyS15302097-210921.43e-07-4.99-5.260NEODyS: "Based on 141 optical observations (of which 6 are rejected as outliers) from 2017-11-13.641 to 2017-11-30.807."

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 5 December '17

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

1820Generated Traffic Report
1600Noted that JPL Sentry has updated its 2017 VW13 risk assessment - see above
1530Noted that NEODyS has updated its 2017 VW13 risk assessment - see above
Noted that JPL Sentry has posted 2017 WT28 as an impact risk - see above
Grabbed MPEC 2017-X14 - Daily Orbit Update - see above
0500Grabbed MPEC 2017-X11 - 2017 WR28 - see above
Grabbed MPEC 2017-X12 - 2017 WS28 - see above
Grabbed MPEC 2017-X13 - 2017 WT28 - see above