Contents  on 17 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 17 April '18

Ten objects reported inside ten LD

Ten minor objects are reported to be between five and ten lunar distances (LD) of Earth today (none closer), and all are outbound. Nearest are 2018 GD5, which heads away from 5.30 to 6.36 LD, while 2018 GK4 gets its closest on this passage, coming to 5.87 LD at 1658 UTC.

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
0.78 LD April 12 2018 GD2 4 m  7.44 to 9.14 LD April 6 - 18 intruder, NHATS target, risk
1.39 LD April 3 2018 GZ 10 m  9.38 to 10.04 LD March 19 - today NHATS target, exits ten LD
1.41 LD April 10 2018 GE2 14 m  9.66 to 11.03 LD April 2 - 17 NHATS target, exits ten LD, risk
3.62 LD April 14 2018 GD5 9 m  5.30 to 6.36 LD April 7 - 21
4.06 LD April 3 2018 GE 11 m  7.05 to 7.41 LD March 13 - April 24 NHATS target, risk
4.36 LD April 13 2018 GP 13 m  8.23 to 9.95 LD April 8 - 18
4.80 LD April 13 2018 GV1 12 m  7.72 to 9.36 LD April 9 - 18
5.87 LD today 2018 GK4 20 m  5.87 LD April 14 - 21 Earth closest at 1658 UTC
8.97 LD today 2018 GC2 15 m  8.97 LD April 13 - 21 NHATS target, Earth closest at 1116 UTC - DOU
9.24 LD April 14 2014 UR 16 m  9.64 to 9.97 LD April 10 - 18 NHATS target

This report was generated at 1842 UTC with first follow-up for departed intruder 2018 GE3 in today's DOU MPEC along with continuing follow-up for approaching objects 2018 EJ4, 2015 DP155, and 1999 FN19, and for passing 2018 GC2, departed 2018 GU1, and distant 2003 FY6.

Approaching Traffic - sorted by 10-LD bubble entry date
Earth passage I D ~Size Distance today  Inside ten LD Notes
8.51 LD April 20 2018 GS3 21 m  14.25 from 18.02 LD April 19 - 21
9.7   LD April 23* 2018 GG4 18 m  21.5 from 24.6 LD April 23 - 24 EPU +/- 5 mins.*, risk
6.2   LD May 8* 2016 JQ5 8 m  49.4 from 52.0 LD May 4 - 11 EPU +/- 14.00 hours*
9.65 LD May 7 1999 FN19 112 m  26.25 from 27.38 LD May 5 - 9 radar/NHATS target - DOU
6.48 LD May 9 388945 2008 TZ3 282 m  45.33 from 47.52 LD May 5 - 13
9.50 LD May 29 68347 2001 KB67 371 m  138.14 from 142.29 LD May 28 - 30 radar target
5.6   LD June 10* 2018 EJ4 186 m  70.8 from 72.1 LD June 4 - 16 EPU +/- 8 mins.*, radar/NHATS target - DOU
8.96 LD June 11 2015 DP155 162 m  47.34 from 48.01 LD June 6 - 15 NHATS target - DOU
* EPU = Earth passage uncertainty


<< Reading:  One of only two asteroids observed to date by telescope before impact was 2008 TC3 (links). Pieces were recovered and a science paper published today in Nature Communications describes some of them as being in the ureilite family, which are believed to be relics of a protoplanet that did not survive our early Solar System. The authors studied mineral inclusions embedded in diamond grains in one of the pieces and conclude that the "ureilite parent body was a Mercury- to Mars-sized planetary embryo." The Associated Press has a report.
        A science preprint posted today tells of an astronomy first using multiple radio telescopes to observe the occultation of a radio galaxy by Main Belt asteroid 372 Palma, resulting in a precision sky location of the object as well as its distance and some idea of its shape. Optical occultation observer Dave Herald, however, takes exception to the paper in comments on the Minor Planet Mailing List.



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 17 April '18

The MPC's NEO Confirmation Page has 47 listings

When last checked at 2358 UTC today, the Minor Planet Center's Near Earth Object discovery Confirmation Page (NEOCP) had 47 objects listed. Of these, 20 were "one nighters." So far The Tracking News has counted a total of 56 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 17 April '18

Minor Planet Electronic Circulars

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


MPEC 2018-H21 - "13:41 UT" - Comet C/2018 F4 (Panstarrs)


MPEC 2018-H20 - "13:29 UT" - 2018 GG5


MPEC 2018-H19 - "13:17 UT" - 2018 GJ5


MPEC 2018-H18 - "13:11 UT" - 2018 GH5


<< DOU on 17 Apr. '18 >>  MPEC 2018-H17 - "12:03 UT" - Daily Orbit Update


MPEC 2018-H16 - "10:31 UT" - 2016 JU24


MPEC 2018-H15 - "10:29 UT" - 2015 TA

Observers  on 17 April '18

A total of 28 observers appear in today's MPECs.

CodeObserver / observatory
H21Astronomical Research Obs. Westfield in Illinois, 2 in MPEC 2018-H17 -- 2018 BN3, 2013 TR132
T05ATLAS Haleakala in Hawaii, 2 in MPEC 2018-H17 -- 444193, 37655
T08ATLAS Mauna Loa in Hawaii, 5 in MPEC 2018-H17 -- 2018 FY1, 2015 DP155, 515049, 337228, 1866
069Baldone Obs. in Latvia, 2 in MPEC 2018-H17 -- 2018 GE3, 164121
K46Bamberg Obs. in Germany, 1 in MPEC 2018-H17 -- 1627
Z84Calar Alto Schmidt in Spain, 2 in MPECs 2018-H19 & 2018-H20 -- 2018 GJ5, 2018 GG5
703Catalina Sky Survey (CSS) in Arizona, 18 in MPECs 2018-H17, 2018-H20 & 2018-H21 -- 2018 GY1, 2018 GR2, 2018 GG5, 2018 GE3, C/2018 F4, 2018 CE2, 2014 FD7, 1999 FN19, 53435, 515446, 505667, 497117, 368664, 36284, 162998, 9856, 8037, 3122
807|Robert Holmes in Illinois via Cerro Tololo Inter-American Obs. (CTIO) in Chile, 5 in MPECs 2018-H15, 2018-H16, 2018-H17, 2018-H18 & 2018-H20 -- 2018 GT4, 2018 GH5, 2018 GG5, 2016 JU24, 2015 TA
A17Guidestar Obs. in Germany, 7 in MPEC 2018-H17 -- 2018 GY1, 2018 GR2, 2018 GL, 2018 GG2, 2018 GB2, 2018 EQ4, 2018 BY2
H15ISON New Mexico Obs. in New Mexico, 1 in MPEC 2018-H17 -- 2018 FY1
K38M57 Obs. in Italy, 1 in MPEC 2018-H17 -- 2018 DX3
H01Magdalena Ridge Obs. (MRO) in New Mexico, 3 in MPECs 2018-H18, 2018-H19 & 2018-H20 -- 2018 GJ5, 2018 GH5, 2018 GG5
568^R. Wainscoat on Mauna Kea in Hawaii, 1 in MPEC 2018-H21 -- C/2018 F4
G96Mt. Lemmon Survey (MLS) in Arizona, 33 in MPECs 2018-H17, 2018-H18, 2018-H19 & 2018-H20 -- 2018 GJ5, 2018 GH5, 2018 GH2, 2018 GG5, 2018 GC2, 2017 EV2, 2016 CX264, 2015 HF9, 2015 GZ45, 2015 FP118, 2015 DD155, 2011 HJ7, 2007 HR, 2005 OX, 2005 LV3, 2005 JD46, 2003 FY6, 1999 AF4, 513497, 498548, 350462, 248926, 186822, 183548, 162635, 152770, 152756, 141053, 138847, 4947, 4581, 4179, 3757
K74Muensterschwarzach Obs. in Germany, 2 in MPEC 2018-H17 -- 2018 BY2, 138847
I41Palomar Transient Factory in southern California, 1 in MPEC 2018-H17 -- 475967
F51Pan-STARRS 1 (PS1) in Hawaii, 9 in MPECs 2018-H17, 2018-H18, 2018-H19 & 2018-H21 -- 2018 GJ5, 2018 GH5, 2018 GA4, C/2018 F4, 2018 EZ9, 2016 GH135, 2005 LH8, 162635, 154229
H45Petit Jean Mtn. South Obs. (PJMSO) in Arkansas, 7 in MPEC 2018-H17 -- 2018 GY1, 2018 GG2, 2018 FQ5, 2018 EJ4, 2018 EB, 2015 XE352, 194126
W98Polonia Obs. in Chile, 1 in MPEC 2018-H17 -- 85490
C95SATINO-1 in France, 1 in MPEC 2018-H17 -- 2011 LY2
204Schiaparelli Obs. in Italy, 1 in MPEC 2018-H20 -- 2018 GG5
Q11Shinshiro Obs., 1 in MPEC 2018-H21 -- C/2018 F4
G403Tony Evans in Portugal via Slooh.com Canary Islands Obs. in the Canary Islands, 1 in MPEC 2018-H17 -- 2018 GJ1
691Spacewatch 0.9m telescope in Arizona, 1 in MPEC 2018-H17 -- 2018 GG2
I93St. Pardon de Conques Obs. in France, 1 in MPEC 2018-H19 -- 2018 GJ5
I52Steward Obs. Mt. Lemmon Station in Arizona, 17 in MPECs 2018-H17, 2018-H18, 2018-H19 & 2018-H20 -- 2018 GY1, 2018 GX1, 2018 GU1, 2018 GT1, 2018 GS2, 2018 GQ1, 2018 GO2, 2018 GM, 2018 GL4, 2018 GK2, 2018 GJ5, 2018 GJ2, 2018 GH5, 2018 GG5, 2018 GG2, 2018 FN4, 2018 FJ29
461SZTE Asteroid Program in Hungary, 1 in MPEC 2018-H21 -- C/2018 F4
T12UH/Tholen NEO Follow-Up 2.24m Telescope in Hawaii, 2 in MPEC 2018-H17 -- 2018 FG5, 2018 BL3
For a list of all participating observatories that have Web addresses, see A/CC's Observatory Links page.

Impact Risk Monitoring  on 17 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 GR4NEODyS15202048-21181535.03e-05-5.47-5.99n/aNEODyS: "Based on 22 optical observations (of which 1 are rejected as outliers) from 2018-04-12.318 to 2018-04-15.240."
2018 GG4NEODyS15202058-207021.22e-07-7.34-7.440NEODyS: "Based on 15 optical observations (of which 1 are rejected as outliers) from 2018-04-13.438 to 2018-04-15.466."
2018 GN2NEODyS1520R E M O V E D-
2018 GL2NEODyS15202060-2117103.58e-06-5.11-5.150NEODyS: "Based on 45 optical observations (of which 0 are rejected as outliers) from 2018-04-11.236 to 2018-04-16.146."
2018 GG2JPL Sentry16362111-211143.9871459e-06-2.45-2.481JPL: Computed at 07:54 today Pacific time based on 71 observations spanning 7.0687 days (2018-Apr-10.39534 to 2018-Apr-17.46404). Diameter approximately 0.480 km. from weighted mean H=19.26.
NEODyS1520211131.21e-06-2.96-3.010NEODyS: "Based on 55 optical observations (of which 0 are rejected as outliers) from 2018-04-10.396 to 2018-04-16.269."
2018 GZNEODyS1520R E M O V E D-
2018 GVNEODyS1520R E M O V E D-
2018 FU1NEODyS15202055-2117621.28e-04-5.13-5.440NEODyS: "Based on 28 optical observations (of which 1 are rejected as outliers) from 2018-03-18.474 to 2018-04-13.632."

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 17 April '18

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

1842Generated Traffic Report
1636Noted that JPL Sentry has updated its 2018 GG2 risk assessment - see above
1520Noted that NEODyS has updated its 2018 FU1 risk assessment - see above
Noted that NEODyS has updated its 2018 GG2 risk assessment - see above
Noted that NEODyS has posted 2018 GG4 as an impact risk - see above
Noted that NEODyS has updated its 2018 GL2 risk assessment - see above
Noted that NEODyS has removed 2018 GN2 as an impact risk - see above
Noted that NEODyS has posted 2018 GR4 as an impact risk - see above
Noted that NEODyS has removed 2018 GV as an impact risk - see above
Noted that NEODyS has removed 2018 GZ as an impact risk - see above
Grabbed MPEC 2018-H15 - 2015 TA - see above
Grabbed MPEC 2018-H16 - 2016 JU24 - see above
Grabbed MPEC 2018-H17 - Daily Orbit Update - see above
Grabbed MPEC 2018-H18 - 2018 GH5 - see above
Grabbed MPEC 2018-H19 - 2018 GJ5 - see above
Grabbed MPEC 2018-H20 - 2018 GG5 - see above
Grabbed MPEC 2018-H21 - Comet C/2018 F4 (Panstarrs) - see above