Contents  on 4 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 4 April '18

Three objects reported inside ten LD

Today three transient natural objects are reported inside ten lunar distances (LD) of Earth, none of them particularly close. The nearest may be unrecovered 2004 FG29, which is calculated to be outbound from about 6.2 to 9.1 LD*, while 2018 EM4 moves out from 7.32 to 8.14 LD.

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  6.2 to 9.1 LD March 30 - tomorrow EPU +/- 1.03 hours*
6.23 LD April 1 2018 EM4 30 m  7.32 to 8.14 LD March 26 - April 6 NHATS target
9.73 LD tomorrow 2018 FW4 33 m  9.73 from 10.14 LD today - tomorrow enters ten LD

This report was generated at 1922 UTC with follow-up in today's DOU MPEC for approaching 2018 EJ4 and distant objects 2007 EJ4DB61 and 2003 EJ4FY6, and with radar from the last three months for now departed objects 2018 FH1, 2018 FB, 2018 DT, and 2018 BM5.

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  13.06 from 13.77 LD April 10 - 18 NHATS target
6.2   LD May 8* 2016 JQ5 8 m  85.2 from 88.2 LD May 4 - 11 EPU +/- 14.00 hours*
9.65 LD May 7 1999 FN19 112 m  40.99 from 42.14 LD May 5 - 9 radar/NHATS target
6.48 LD May 9 388945 2008 TZ3 282 m  75.45 from 77.93 LD May 5 - 13
9.50 LD May 29 68347 2001 KB67 371 m  196.95 from 201.92 LD May 28 - 30 radar target
5.5   LD June 10* 2018 EJ4 180 m  87.2 from 88.5 LD June 4 - 16 EPU +/- 38 mins.*, radar/NHATS target - DOU
8.96 LD June 11 2015 DP155 162 m  55.99 from 56.67 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. "Distant" is used here to describe objects that have approached Earth within ten LD since A/CC began these traffic reports eleven years ago but are not presently coming so close. 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.

Radar Astrometry  on 4 April '18

Radar observation of eight objects

The JPL Solar System Dynamics Group Radar Astrometry database has added or updated the following small-body radar observing work:


Data update noted at 1603 UTC when the database was dated 4 April



Photometry and some astrometry is needed for upcoming radar targets. See Arecibo and Goldstone schedules.

NEOCP Activity  on 4 April '18

The MPC's NEO Confirmation Page has 10 listings

When last checked at 2358 UTC today, the Minor Planet Center's Near Earth Object discovery Confirmation Page (NEOCP) had ten objects listed. Of these, five were "one nighters." So far The Tracking News has counted a total of thirteen 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 4 April '18

Minor Planet Electronic Circulars

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


MPEC 2018-G18 - "14:21 UT" - 2018 FJ29


<< DOU on 4 Apr. '18 >>  MPEC 2018-G17 - "12:01 UT" - Daily Orbit Update

Observers  on 4 April '18

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

CodeObserver / observatory
251Arecibo in Puerto Rico, 8 in radar -- 2018 FH1, 2018 FB, 2018 DT, 2018 BT1, 2018 BM5, 2006 WE4, 96590, 306383
T05ATLAS Haleakala in Hawaii, 1 in MPEC 2018-G17 -- 85953
160Castelmartini Obs. in Italy, 1 in MPEC 2018-G17 -- 85953
703Catalina Sky Survey in Arizona, 1 in MPEC 2018-G17 -- 85953
807|Robert Holmes in Illinois via Cerro Tololo Inter-American Obs. in Chile, 1 in MPEC 2018-G18 -- 2018 FJ29
J95Great Shefford Obs. in England, 2 in MPEC 2018-G17 -- 2018 FJ5, 2010 GD35
H15ISON New Mexico Obs. in New Mexico, 1 in MPEC 2018-G17 -- 172034
H01Magdalena Ridge Obs. in New Mexico, 1 in MPEC 2018-G18 -- 2018 FJ29
G96Mt. Lemmon Survey in Arizona, 1 in MPEC 2018-G18 -- 2018 FJ29
644NEAT's Mt. Palomar telescope in southern California, 1 in MPEC 2018-G17 -- 66063
J69North Obs. in England, 1 in MPEC 2018-G17 -- 85953
Z80Northolt Branch Obs. in England, 4 in MPEC 2018-G17 -- 2018 DX3, 2012 DG61, 85953, 194126
G34Oberfrauendorf Obs. in Germany, 3 in MPEC 2018-G17 -- 2018 DX3, 2015 XE352, 85953
654Pomona College Table Mtn. Obs. (PCTMO) in southern California, 6 in MPEC 2018-G17 -- 2017 PR25, 2017 FJ90, 65679, 498548, 496005, 163696
H36Sandlot Obs. in Kansas, 2 in MPEC 2018-G17 -- 2018 DX3, 2017 WH14
Y00SONEAR in Brazil, 1 in MPEC 2018-G17 -- 85953
691Spacewatch 0.9m telescope in Arizona, 12 in MPEC 2018-G17 -- 2018 FV3, 2018 FS3, 2018 FJ4, 2018 DX3, 2018 BY2, 2017 YE5, 2017 TV4, 2016 CX264, 2015 XE352, 2007 DB61, 2003 FY6, 2002 TC60
291Spacewatch 1.8m telescope in Arizona, 7 in MPEC 2018-G17 -- 2018 FJ5, 2018 FD, 2018 ER1, 2018 EL4, 2017 SS19, 2014 YJ14, 2004 EU22
I52Steward Obs. Mt. Lemmon Station in Arizona, 31 in MPECs 2018-G17 & 2018-G18 -- 2018 FY1, 2018 FY, 2018 FV4, 2018 FV3, 2018 FU, 2018 FS3, 2018 FS1, 2018 FQ5, 2018 FM4, 2018 FL4, 2018 FL3, 2018 FJ5, 2018 FJ29, 2018 FF2, 2018 FF1, 2018 FE5, 2018 FC1, 2018 FB1, 2018 EZ, 2018 EY3, 2018 EW3, 2018 EM2, 2018 EJ4, 2018 EE4, 2018 EE, 2018 EB, 2018 CG2, 2017 YP4, 2017 YE5, 2017 WH14, 2013 GT38
T12UH/Tholen NEO Follow-Up 2.24m Telescope in Hawaii, 1 in MPEC 2018-G17 -- 2018 ED4
For a list of all participating observatories that have Web addresses, see A/CC's Observatory Links page.

Impact Risk Monitoring  on 4 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 Sentry16032084-208411.191e-07-4.10-4.100JPL: Computed at 07:29 today Pacific time based on 46 observations spanning 10.915 days (2018-Mar-24.43016 to 2018-Apr-04.34495). Diameter approximately 0.370 km. from weighted mean H=19.83.
2018 EL4JPL Sentry16032110-211031.5619e-06-6.33-6.620JPL: Computed at 07:35 today Pacific time based on 71 observations spanning 21.101 days (2018-Mar-14.20994 to 2018-Apr-04.31129). Diameter approximately 0.032 km. from weighted mean H=25.15.
2018 ED4JPL Sentry1603R E M O V E DJPL: Risk listing removed at 1427 UTC today
2004 FU162NEODyS16032018-21161842.26e-06-6.82-7.690NEODyS: "Based on 4 optical observations (of which 0 are rejected as outliers) from 2004-03-31.278 to 2004-03-31.309."
2002 EM7NEODyS1603211721.04e-08-8.09-8.10NEODyS: "Based on 69 optical observations (of which 0 are rejected as outliers) from 2002-03-12.307 to 2002-04-06.269."

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 4 April '18

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

1922Generated Traffic Report
1603Noted that NEODyS has posted 2002 EM7 as an impact risk - see above
Noted that NEODyS has updated its 2004 FU162 risk assessment - see above
Noted that JPL Sentry 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 JPL Sentry has updated its 2018 FJ5 risk assessment - see above
Grabbed MPEC 2018-G17 - Daily Orbit Update - see above
Grabbed MPEC 2018-G18 - 2018 FJ29 - see above
Noted Radar Astrometry database update - see above