Contents  on 5 April '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 5 April '18

Three objects reported inside ten LD

There are three asteroids reported traveling within ten lunar distances (LD) of our planet today, none closer than eight LD and all moving away.

Neighborhood Traffic - sorted by Earth passage distance, grouped by 1.0, 2.41, 5.0 & 10.0 LD boundaries
Earth passage I D ~Size Distance today  Inside ten LD Notes
4.0   LD April 2* 2004 FG29 21 m  9.1 to 12.2 LD March 30 - today EPU +/- 1.03 hours*, exits ten LD
6.23 LD April 1 2018 EM4 30 m  8.14 to 9.11 LD March 26 - tomorrow NHATS target - DOU
9.73 LD today 2018 FW4 33 m  9.73 LD yesterday - today Earth closest at 0227 UTC

This report was generated at 1949 UTC with today's DOU MPEC posting the recovery of distant risk-listed 2016 SR2 and follow-up for approaching 2018 EJ4, departed 2018 FW, and distant objects 2007 DB61 and 2003 FY6, plus astrometry from last month for outbound 2018 EM4 and now departed objects 2018 FN3, 2018 FW1, 2018 FB, 2018 ET1, 2018 EH, and risk-listed 2018 EB4.

Approaching Traffic - sorted by 10-LD bubble entry date
Earth passage I D ~Size Distance today  Inside ten LD Notes
9.24 LD April 14 2014 UR 16 m  12.39 from 13.06 LD April 10 - 18 NHATS target
6.2   LD May 8* 2016 JQ5 8 m  82.3 from 85.2 LD May 4 - 11 EPU +/- 14.00 hours*
9.65 LD May 7 1999 FN19 112 m  39.84 from 40.99 LD May 5 - 9 radar/NHATS target
6.48 LD May 9 388945 2008 TZ3 282 m  73.00 from 75.45 LD May 5 - 13
9.50 LD May 29 68347 2001 KB67 371 m  192.04 from 196.95 LD May 28 - 30 radar target
5.5   LD June 10* 2018 EJ4 183 m  85.9 from 87.1 LD June 4 - 16 EPU +/- 34 mins.*, radar/NHATS target - DOU
8.96 LD June 11 2015 DP155 162 m  55.31 from 55.99 LD June 6 - 15 NHATS target
* EPU = Earth passage uncertainty



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. "LD*" indicates some uncertainty in object passage time and distance. See also current sky chart and object details (alt-details), ephemerides, and today's timeline.

NEOCP Activity  on 5 April '18

The MPC's NEO Confirmation Page has 12 listings

When last checked at 2358 UTC today, the Minor Planet Center's Near Earth Object discovery Confirmation Page (NEOCP) had twelve objects listed. Of these, four were "one nighters." So far The Tracking News has counted a total of seventeen 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 April '18

Minor Planet Electronic Circulars

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


MPEC 2018-G21 - "23:44 UT" - 2018 GB


<< DOU on 5 Apr. '18 >>  MPEC 2018-G20 - "12:01 UT" - Daily Orbit Update


MPEC 2018-G19 - "10:08 UT" - 2018 GA

Observers  on 5 April '18

A total of 20 observers appear in today's MPECs.

CodeObserver / observatory
H21Astronomical Research Obs. Westfield in Illinois, 1 in MPEC 2018-G21 -- 2018 GB
807|Robert Holmes in Illinois via Cerro Tololo Inter-American Obs. (CTIO) in Chile, 26 in MPEC 2018-G20 -- 2018 FX1, 2018 FW2, 2018 FW, 2018 FP3, 2018 FO5, 2018 FK2, 2018 FH5, 2018 FH2, 2018 FD3, 2018 FA3, 2018 EZ3, 2018 EK4, 2018 EC9, 2018 DJ4, 2018 DE2, 2018 DA2, 2018 CZ13, 2018 CU1, 2018 BP5, 2018 BO3, 2018 AM12, 2017 YF5, 2017 YB8, 2017 XB2, 2017 WO28, 2017 UA1
850Cordell-Lorenz Obs. in Tennessee, 1 in MPEC 2018-G20 -- 85953
006Fabra Obs. in Spain, 1 in MPEC 2018-G20 -- 85953
K88GINOP-KHK in Hungary, 1 in MPEC 2018-G19 -- 2018 GA
H15ISON New Mexico Obs. in New Mexico, 1 in MPEC 2018-G20 -- 9856
Q62`Steven M. Tilley in Louisiana via iTelescope Obs. Siding Spring in New South Wales, 1 in MPEC 2018-G20 -- 2018 FQ5
246KLENOT in the Czech Republic, 3 in MPEC 2018-G20 -- 2018 BY2, 2015 XE352, 2015 RA83
H01Magdalena Ridge Obs. (MRO) in New Mexico, 2 in MPECs 2018-G19 & 2018-G21 -- 2018 GB, 2018 GA
G96Mt. Lemmon Survey (MLS) in Arizona, 12 in MPECs 2018-G20 & 2018-G21 -- 2018 GB, 2018 CX13, 2014 QP266, 2011 GC60, 2009 FG1, 515049, 513550, 164217, 164207, 163691, 101873, 1866
J69North Obs. in England, 1 in MPEC 2018-G20 -- 2018 EB
H45Petit Jean Mtn. South Obs. (PJMSO) in Arkansas, 2 in MPEC 2018-G20 -- 2018 BY2, 2015 XE352
204Schiaparelli Obs. in Italy, 14 in MPEC 2018-G20 -- 2018 FW1, 2018 FN3, 2018 FB, 2018 EZ, 2018 EU2, 2018 ET1, 2018 EM4, 2018 EH, 2018 EF1, 2018 EB4, 2018 DE2, 2018 CU1, 2018 BO3, 2007 EM
691Spacewatch 0.9m telescope in Arizona, 13 in MPEC 2018-G20 -- 2018 FS3, 2018 DX3, 2018 BY2, 2017 YE5, 2017 TV4, 2016 CX264, 2015 XE352, 2015 JY1, 2014 QK434, 2013 JN22, 2011 HJ7, 2007 HR, 2003 FY6
291Spacewatch 1.8m telescope in Arizona, 11 in MPEC 2018-G20 -- 2018 FW2, 2018 FV3, 2018 FO3, 2018 FJ5, 2018 ER1, 2018 EL4, 2016 SR2, 2011 HJ7, 2007 DB61, 2004 EU22, 2001 HW15
W34Squirrel Valley Obs. in North Carolina, 2 in MPEC 2018-G20 -- 2015 XE352, 337084
I52Steward Obs. Mt. Lemmon Station in Arizona, 25 in MPECs 2018-G20 & 2018-G21 -- 2018 GB, 2018 FY4, 2018 FU4, 2018 FU, 2018 FS3, 2018 FS1, 2018 FO5, 2018 FL3, 2018 FK4, 2018 FJ5, 2018 FE2, 2018 EY3, 2018 ER4, 2018 ER1, 2018 EM2, 2018 EJ4, 2018 EB, 2018 DJ4, 2018 DF2, 2018 DB2, 2018 BO3, 2017 UA1, 2017 TV4, 2017 SR32, 163732
T12UH/Tholen NEO Follow-Up 2.24m Telescope in Hawaii, 1 in MPEC 2018-G20 -- 2016 SR2
L01Visnjan Obs., 1 in MPEC 2018-G21 -- 2018 GB
C51WISE in Earth polar orbit, 2 in MPECs 2018-G19 & 2018-G20 -- 2018 GA, 333888
For a list of all participating observatories that have Web addresses, see A/CC's Observatory Links page.

Impact Risk Monitoring  on 5 April '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.
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
2018 FJ5JPL Sentry16152084-208417.318e-08-4.34-4.340JPL: Computed at 08:06 today Pacific time based on 53 observations spanning 11.913 days (2018-Mar-24.43016 to 2018-Apr-05.34349). Diameter approximately 0.360 km. from weighted mean H=19.88.
NEODyS16152084-208832.41e-07-3.78-3.780NEODyS: "Based on 43 optical observations (of which 1 are rejected as outliers) from 2018-03-24.431 to 2018-04-04.346."
2018 FU1NEODyS16152059-2117321.19e-05-6.20-6.420NEODyS: "Based on 26 optical observations (of which 1 are rejected as outliers) from 2018-03-18.474 to 2018-03-30.524."
2018 EL4JPL Sentry16152110-211032.6021e-07-7.10-7.420JPL: Computed at 08:12 today Pacific time based on 74 observations spanning 22.115 days (2018-Mar-14.20994 to 2018-Apr-05.32462). Diameter approximately 0.032 km. from weighted mean H=25.15.
NEODyS16152102-211543.0e-07-7.02-7.310NEODyS: "Based on 66 optical observations (of which 0 are rejected as outliers) from 2018-03-14.211 to 2018-04-04.312."
2018 ED4NEODyS1615R E M O V E D-
2018 EB4JPL Sentry16152099-210322.62933e-06-5.95-5.960JPL: Computed at 07:56 today Pacific time based on 85 observations spanning 3.7107 days (2018-Mar-12.34928 to 2018-Mar-16.06002). Diameter approximately 0.028 km. from weighted mean H=25.41.
2016 SR2JPL Sentry1615R E M O V E DJPL: Risk listing removed at 1442 UTC today

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 April '18

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

2358Grabbed MPEC 2018-G21 - 2018 GB - see above
1949Generated Traffic Report
1615Noted that JPL Sentry has removed 2016 SR2 as an impact risk - see above
Noted that JPL Sentry has updated its 2018 EB4 risk assessment - see above
Noted that NEODyS has removed 2018 ED4 as an impact risk - see above
Noted that JPL Sentry has updated its 2018 EL4 risk assessment - see above
Noted that NEODyS has updated its 2018 EL4 risk assessment - see above
Noted that JPL Sentry has updated its 2018 FJ5 risk assessment - see above
Noted that NEODyS has updated its 2018 FJ5 risk assessment - see above
Noted that NEODyS has updated its 2018 FU1 risk assessment - see above
Grabbed MPEC 2018-G19 - 2018 GA - see above
Grabbed MPEC 2018-G20 - Daily Orbit Update - see above