Contents  on 1 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 1 January '18

Seven objects reported inside ten LD

Today there are seven asteroids reported inside ten lunar distances (LD) of Earth. Nearest are 2017 YD7, inbound from 6.73 to 5.32 LD, and 2017 YS1, moving away from 5.69 to 6.38 LD, while risk-listed intruder 2017 YE7 zooms out from 5.76 to 10.27 LD, leaving our ten-LD traffic reporting "bubble."

Earth passage I D ~Size Distance today  Inside ten LD Notes
0.58 LD Dec. 28 2017 YZ4 8 m  7.10 to 9.22 LD Dec. 23 - tomorrow intruder, NHATS target
0.80 LD Dec. 30 2017 YE7 7 m  5.76 to 10.27 LD Dec. 28 - today intruder, exits ten LD, risk
1.93 LD Dec. 24 2017 YS1 6 m  5.69 to 6.38 LD Dec. 11 - Jan. 7 NHATS target
2.24 LD Dec. 27 2017 YD2 6 m  9.39 to 11.22 LD Dec. 21 - today NHATS target, exits ten LD, risk
4.73 LD Jan. 3 2017 YD7 12 m  5.32 from 6.73 LD Dec. 30 - Jan. 6 NHATS target
4.84 LD Dec. 19 2017 YW3 17 m  9.43 to 10.02 LD Dec. 5 - today NHATS target, exits ten LD
7.74 LD Dec. 30 2017 YU1 20 m  8.26 to 9.00 LD Dec. 26 - Jan. 3 NHATS target
Approaching (sorted by 10-LD bubble entry date)
3.7   LD Feb. 24* 2017 DR109 10 m  110.1 from 112.9 LD Feb. 18 - March 1 EPU +/- 30 mins.*, NHATS target
3.76 LD March 7 2017 VR12 272 m  87.18 from 88.68 LD Feb. 28 - March 13 radar/NHATS target
* EPU = Earth passage uncertainty

This report was generated at 1824 UTC with follow-up in today's DOU MPEC for departed objects 2017 YH1 and 2017 VT14, plus astrometry from December for 2017 YB1 and 2017 WB.



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 1 January '18

The MPC's NEO Confirmation Page has 58 listings

When last checked at 2359 UTC today, the Minor Planet Center's Near Earth Object discovery Confirmation Page (NEOCP) had 58 objects listed. Of these, 23 were "one nighters." So far The Tracking News has counted a total of 75 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 1 January '18

Minor Planet Electronic Circulars

As of last check at 2359 UTC, there have been four MPECs posted today from the International Astronomical Union's Minor Planet Center in Cambridge, Massachusetts.


<< DOU on 1 Jan. '18 >>  MPEC 2018-A04 - "13:04 UT" - Daily Orbit Update


MPEC 2018-A03 - "03:42 UT" - 2017 YV7


MPEC 2018-A02 - "03:28 UT" - 2017 YU7


MPEC 2018-A01 - "02:11 UT" - 2017 YT7

Observers  on 1 January '18

Sixteen observers appear in today's MPECs.

CodeObserver / observatory
H21Astronomical Research Obs. Westfield in Illinois, 11 in MPEC 2018-A04 -- 2017 YK5, 2017 YB1, 2017 WY13, 2017 WE13, 2017 WB, 2017 VX14, 2017 VM13, 2017 SP19, 2017 OQ68, 2017 NL6, 88188
T05ATLAS Haleakala in Hawaii, 13 in MPEC 2018-A04 -- 2017 QL33, 2016 CL32, 2016 AU8, 53110, 505667, 415029, 333888, 276703, 27346, 253841, 8567, 7977, 1627
T08ATLAS Mauna Loa in Hawaii, 8 in MPECs 2018-A03 & 2018-A04 -- 2017 YV7, 2017 YP4, 2017 QL33, 348314, 302311, 163696, 137062, 3122
160Castelmartini Obs. in Italy, 10 in MPEC 2018-A04 -- 2017 VU14, 96590, 507366, 505667, 415029, 190208, 162011, 143992, 8567, 3200
807|Robert Holmes in Illinois via Cerro Tololo Inter-American Obs. (CTIO) in Chile, 9 in MPECs 2018-A02, 2018-A03 & 2018-A04 -- 2017 YZ1, 2017 YV7, 2017 YU7, 2017 YS3, 2017 YH, 2017 XL62, 2017 XJ1, 2017 WR13, 2017 TV4
595Farra d'Isonzo Obs. in Italy, 1 in MPEC 2018-A03 -- 2017 YV7
568_Marco Micheli on Mauna Kea in Hawaii, 1 in MPEC 2018-A02 -- 2017 YU7
G96Mt. Lemmon Survey in Arizona, 1 in MPEC 2018-A01 -- 2017 YT7
K74Muensterschwarzach Obs. in Germany, 7 in MPEC 2018-A04 -- 2017 YR1, 2017 QL33, 1999 AF4, 504928, 163696, 12711, 3122
F51Pan-STARRS 1 (PS1) in Hawaii, 17 in MPECs 2018-A01, 2018-A02 & 2018-A04 -- 2017 YY5, 2017 YU7, 2017 YT7, 2017 YA2, 2017 VT14, 2017 SO17, 2007 AG, 85839, 506859, 500749, 163691, 154652, 142563, 141498, 8566, 8037, 4487
L04ROASTERR-1 in Romania, 1 in MPEC 2018-A04 -- 2017 YH1
691Spacewatch 0.9m telescope in Arizona, 1 in MPEC 2018-A02 -- 2017 YU7
291Spacewatch 1.8m telescope in Arizona, 1 in MPEC 2018-A02 -- 2017 YU7
I52Steward Obs. Mt. Lemmon Station in Arizona, 2 in MPECs 2018-A01 & 2018-A02 -- 2017 YU7, 2017 YT7
926Tenagra II Obs. in Arizona, 2 in MPECs 2018-A01 & 2018-A03 -- 2017 YV7, 2017 YT7
I15Wishing Star Obs. in Rhode Island, 1 in MPEC 2018-A04 -- 17511
For a list of all participating observatories that have Web addresses, see A/CC's Observatory Links page.

Impact Risk Monitoring  on 1 January '18

Summary Risk Table for Risk Assessments Updated Today   (last checks: NEODyS at 2359 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 YE7NEODyS1700206314.78e-09-9.74-9.740NEODyS: "Based on 23 optical observations (of which 2 are rejected as outliers) from 2017-12-28.280 to 2017-12-30.218."
2017 YL6NEODyS17002037-2111239.91e-08-5.68-6.10NEODyS: "Based on 14 optical observations (of which 1 are rejected as outliers) from 2017-12-24.572 to 2017-12-29.381."
2017 YS3NEODyS2359R E M O V E D-
JPL Sentry1700R E M O V E DJPL: Risk listing removed at 1547 UTC today
2017 YZ1NEODyS23592047-2116101.6e-05-2.46-2.50NEODyS #2 for the day: "Based on 40 optical observations (of which 4 are rejected as outliers) from 2017-12-20.426 to 2018-01-01.251."
JPL Sentry17002047-2117232.11064435e-05-2.31-2.330JPL: Computed at 08:00 today Pacific time based on 40 observations spanning 11.826 days (2017-Dec-20.42481 to 2018-Jan-01.25034). Diameter approximately 0.250 km. from weighted mean H=20.66.

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 1 January '18

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

2359Noted that NEODyS has removed 2017 YS3 as an impact risk - see above
Noted that NEODyS has updated its 2017 YZ1 risk assessment - see above
1824Generated Traffic Report
1700Noted that NEODyS has posted 2017 YE7 as an impact risk - see above
Noted that NEODyS has updated its 2017 YL6 risk assessment - see above
Noted that JPL Sentry has removed 2017 YS3 as an impact risk - 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 2018-A04 - Daily Orbit Update - see above
0436Grabbed MPEC 2018-A01 - 2017 YT7 - see above
Grabbed MPEC 2018-A02 - 2017 YU7 - see above
Grabbed MPEC 2018-A03 - 2017 YV7 - see above