Contents  on 21 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 21 April '18

Nine objects reported inside ten LD

Nine objects are known to be inside ten lunar distances (LD) of Earth today. Nearest are newly announced 2018 HS, outbound from 5.71 to 8.49 LD, and 2018 HT, which comes its closest to our planet this time around -- 7.09 LD at 0638 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
3.62 LD April 14 2018 GD5 9 m  9.96 to 11.23 LD April 7 - 21 NHATS target, exits ten LD
4.06 LD April 3 2018 GE 11 m  8.51 to 8.89 LD March 13 - April 24 NHATS target - DOU
5.12 LD yesterday 2018 HS 33 m  5.71 to 8.49 LD April 18 - 22 NEW - MPEC
5.87 LD April 17 2018 GK4 20 m  9.92 to 11.95 LD April 14 - 21 exits ten LD
7.09 LD today 2018 HT 14 m  7.09 LD April 17 - 25 NEW, Earth closest at 0638 UTC - MPEC
7.96 LD April 18 2018 HU 27 m  9.35 to 10.66 LD April 15 - 21 NEW, exits ten LD - MPEC
7.99 LD today 2018 HN 35 m  7.99 LD April 19 - 24 NHATS target, Earth closest at 2007 UTC - DOU
8.52 LD yesterday 2018 GS3 23 m  8.73 to 10.63 LD April 19 - 21 exits ten LD
8.97 LD April 17 2018 GC2 15 m  9.79 to 10.28 LD April 13 - 21 NHATS target, exits ten LD

This report was generated at 2212 UTC with the discovery of passing 2018 HT (MPEC) and outbound objects 2018 HU (MPEC) and 2018 HS (MPEC). Today's DOU MPEC has first follow-up for departed 2018 GS5 and additional observation of passing 2018 HN and departed 2018 HO, along with continuing follow-up for approaching objects 2018 EJ4, 388945 2008 TZ3, 1999 FN19, and risk-listed 2018 GG4, and for outbound 2018 GE and departed risk-listed 2018 GE2.

Approaching Traffic - sorted by 10-LD bubble entry date
Earth passage I D ~Size Distance today  Inside ten LD Notes
9.72 LD April 23 2018 GG4 19 m  11.25 from 13.27 LD tomorrow - April 24 risk - DOU
6.2   LD May 8* 2016 JQ5 8 m  39.3 from 41.8 LD May 4 - 11 EPU +/- 14.00 hours*
9.65 LD May 7 1999 FN19 112 m  21.81 from 22.92 LD May 5 - 9 radar/NHATS target - DOU
6.48 LD May 9 388945 2008 TZ3 282 m  36.73 from 38.85 LD May 5 - 13 DOU
9.50 LD May 29 68347 2001 KB67 371 m  122.13 from 126.05 LD May 28 - 30 radar target
5.6   LD June 10* 2018 EJ4 186 m  65.9 from 67.1 LD June 4 - 16 EPU +/- 6 mins.*, radar/NHATS target - DOU
8.96 LD June 11 2015 DP155 162 m  44.64 from 45.32 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. See also current sky chart and object details (alt-details), ephemerides, and today's timeline.

NEOCP Activity  on 21 April '18

The MPC's NEO Confirmation Page has 41 listings

When last checked at 2359 UTC today, the Minor Planet Center's Near Earth Object discovery Confirmation Page (NEOCP) had 41 objects listed. Of these, 25 were "one nighters." So far The Tracking News has counted a total of 48 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 21 April '18

Minor Planet Electronic Circulars

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


MPEC 2018-H61 - "19:33 UT" - 2018 HT


MPEC 2018-H60 - "19:29 UT" - 2018 HS


MPEC 2018-H59 - "19:25 UT" - 2018 HU


MPEC 2018-H58 - "19:21 UT" - 2018 HR


MPEC 2018-H57 - "19:18 UT" - 2018 HQ


<< DOU on 21 Apr. '18 >>  MPEC 2018-H56 - "12:02 UT" - Daily Orbit Update

Observers  on 21 April '18

A total of 47 observers appear in today's MPECs.

CodeObserver / observatory
C97Al-Fulaij Obs., 5 in MPEC 2018-H56 -- 2018 GY1, 2018 DX3, 172034, 152931, 1036
H21Astronomical Research Obs. Westfield in Illinois, 6 in MPEC 2018-H56 -- 2018 GN2, 2018 FU, 2018 FL4, 2017 UD1, 2010 CF19, 66253
C77Bernezzo Obs. in Italy, 1 in MPEC 2018-H60 -- 2018 HS
160Castelmartini Obs. in Italy, 4 in MPECs 2018-H56 & 2018-H60 -- 2018 HS, 2018 FQ5, 36183, 25916
703Catalina Sky Survey (CSS) in Arizona, 15 in MPECs 2018-H56, 2018-H59 & 2018-H60 -- 2018 HU, 2018 HS, 2018 GY1, 2018 GG2, 2018 FS3, 2018 DB2, 1999 FN19, 511808, 497117, 475967, 474574, 9856, 8037, 6037, 1864
V06Catalina Sky Survey Kuiper Telescope (CSS-Kuiper) in Arizona, 8 in MPEC 2018-H56 -- 2018 GZ1, 2018 GX3, 2018 GV3, 2018 GR4, 2018 GQ1, 2018 FF1, 2016 OY2, 2016 FT3
107Cavezzo Obs. in Italy, 1 in MPEC 2018-H56 -- 85953
807|Robert Holmes in Illinois via Cerro Tololo Inter-American Obs. in Chile, 1 in MPEC 2018-H57 -- 2018 HQ
850Cordell-Lorenz Obs. in Tennessee, 1 in MPEC 2018-H56 -- 475967
K87Dettelbach Vineyard Obs. in Germany, 3 in MPECs 2018-H56 & 2018-H59 -- 2018 HU, 2018 HN, 2018 GH
113Drebach Obs. in Germany, 2 in MPECs 2018-H59 & 2018-H60 -- 2018 HU, 2018 HS
734Farpoint Obs. in Kansas, 2 in MPECs 2018-H59 & 2018-H60 -- 2018 HU, 2018 HS
595Farra d'Isonzo Obs. in Italy, 2 in MPECs 2018-H59 & 2018-H60 -- 2018 HU, 2018 HS
K88GINOP-KHK in Hungary, 1 in MPEC 2018-H59 -- 2018 HU
J95Great Shefford Obs. in England, 3 in MPECs 2018-H59, 2018-H60 & 2018-H61 -- 2018 HU, 2018 HT, 2018 HS
A17Guidestar Obs. in Germany, 1 in MPEC 2018-H59 -- 2018 HU
C43Hoyerswerda Obs. in Germany, 2 in MPECs 2018-H59 & 2018-H60 -- 2018 HU, 2018 HS
P93JAXA Space Tracking & Communications Center (JAXA STCC) in Japan, 2 in MPECs 2018-H59 & 2018-H60 -- 2018 HU, 2018 HS
246KLENOT in the Czech Republic, 8 in MPECs 2018-H56, 2018-H59, 2018-H60 & 2018-H61 -- 2018 HU, 2018 HT, 2018 HS, 2018 GY1, 2018 GS4, 2018 GO2, 2018 GJ1, 2018 GE2
Z43Landehen Obs., 6 in MPEC 2018-H56 -- 2018 BY2, 85628, 337084, 194126, 1866, 1627
K30Luscherz Obs. in Switzerland, 1 in MPEC 2018-H60 -- 2018 HS
900Moriyama Obs. in Japan, 1 in MPEC 2018-H60 -- 2018 HS
G96Mt. Lemmon Survey (MLS) in Arizona, 24 in MPECs 2018-H56, 2018-H57, 2018-H58 & 2018-H61 -- 2018 HT, 2018 HR, 2018 HQ, 2018 GR2, 2018 GJ2, 2018 GJ1, 2018 BY2, 2017 XH62, 2013 JN22, 2012 FN62, 2005 FN4, 53435, 514652, 368664, 348400, 332446, 330659, 194126, 190208, 162998, 162882, 143527, 12923, 7753
C47Nonndorf Obs. in Austria, 1 in MPEC 2018-H60 -- 2018 HS
J69North Obs. in England, 2 in MPEC 2018-H56 -- 2018 HN, 2018 GY1
Z80Northolt Branch Obs. in England, 1 in MPEC 2018-H60 -- 2018 HS
G34Oberfrauendorf Obs. in Germany, 1 in MPEC 2018-H60 -- 2018 HS
K63Pascoli Obs. in Italy, 2 in MPECs 2018-H59 & 2018-H60 -- 2018 HU, 2018 HS
K81PMPHR Obs., 1 in MPEC 2018-H56 -- 138847
D29Purple Mtn. Obs. Xuyi Station in China, 2 in MPEC 2018-H56 -- 515446, 9856
L04ROASTERR-1 in Romania, 1 in MPEC 2018-H59 -- 2018 HU
K61Rokycany Obs. in the Czech Republic, 2 in MPECs 2018-H59 & 2018-H60 -- 2018 HU, 2018 HS
B04Saint-Barthelemy Obs. in Italy, 1 in MPEC 2018-H59 -- 2018 HU
104San Marcello Pistoiese Obs. in Italy, 3 in MPECs 2018-H56, 2018-H59 & 2018-H60 -- 2018 HU, 2018 HS, 2017 VL15
C95SATINO-1 in France, 2 in MPECs 2018-H56 & 2018-H60 -- 2018 HS, 2018 HO
204Schiaparelli Obs. in Italy, 3 in MPECs 2018-H59, 2018-H60 & 2018-H61 -- 2018 HU, 2018 HT, 2018 HS
033Schwarzschild Obs. in Germany, 1 in MPEC 2018-H60 -- 2018 HS
Y00SONEAR in Brazil, 2 in MPECs 2018-H56 & 2018-H60 -- 2018 HS, 2018 DX3
587Sormano Obs. in Italy, 1 in MPEC 2018-H60 -- 2018 HS
691Spacewatch 0.9m telescope in Arizona, 25 in MPEC 2018-H56 -- 2018 GZ4, 2018 GZ1, 2018 GY4, 2018 GW4, 2018 GW3, 2018 GV5, 2018 GN4, 2018 GM4, 2018 GG4, 2018 GE2, 2018 GA4, 2018 FS3, 2018 FS1, 2018 FJ4, 2018 FH, 2018 FF1, 2018 EM2, 2018 EE, 2018 BA7, 2016 OY2, 2016 CX264, 2015 UC67, 2013 JN22, 498548, 162635
291Spacewatch 1.8m telescope in Arizona, 8 in MPEC 2018-H56 -- 2018 GX3, 2018 GV3, 2018 GS5, 2018 GR4, 2018 GL2, 2018 GJ, 2018 GE, 2017 RP2
W34Squirrel Valley Obs. in North Carolina, 2 in MPEC 2018-H56 -- 511808, 388945
I93St. Pardon de Conques Obs. in France, 2 in MPECs 2018-H59 & 2018-H60 -- 2018 HU, 2018 HS
I52Steward Obs. Mt. Lemmon Station in Arizona, 48 in MPECs 2018-H56, 2018-H57, 2018-H58, 2018-H59, 2018-H60 & 2018-H61 -- 2018 HU, 2018 HT, 2018 HS, 2018 HR, 2018 HQ, 2018 HE, 2018 HC, 2018 HB, 2018 GZ3, 2018 GY1, 2018 GX4, 2018 GW3, 2018 GW, 2018 GT3, 2018 GT1, 2018 GS4, 2018 GS1, 2018 GR5, 2018 GQ5, 2018 GQ2, 2018 GP5, 2018 GO4, 2018 GO2, 2018 GM, 2018 GL4, 2018 GL1, 2018 GL, 2018 GK1, 2018 GJ5, 2018 GJ4, 2018 GJ2, 2018 GJ1, 2018 GG4, 2018 GF4, 2018 GE5, 2018 GE2, 2018 GB2, 2018 GA5, 2018 GA, 2018 FS3, 2018 FS1, 2018 FL3, 2018 FK29, 2018 EJ4, 2018 DB2, 2018 CK14, 2018 AO18, 2016 LM11
T12UH/Tholen NEO Follow-Up 2.24m Telescope in Hawaii, 1 in MPEC 2018-H56 -- 2017 DO36
L01Visnjan Obs., 5 in MPECs 2018-H57, 2018-H58, 2018-H59, 2018-H60 & 2018-H61 -- 2018 HU, 2018 HT, 2018 HS, 2018 HR, 2018 HQ
198Wildberg Obs. in Germany, 1 in MPEC 2018-H59 -- 2018 HU
For a list of all participating observatories that have Web addresses, see A/CC's Observatory Links page.

Impact Risk Monitoring  on 21 April '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
2018 GA5JPL Sentry16342099-209911.978e-10-6.49-6.490JPL: Computed at 07:51 today Pacific time based on 50 observations spanning 7.9021 days (2018-Apr-13.46779 to 2018-Apr-21.36991). Diameter approximately 0.730 km. from weighted mean H=18.34.
2018 GR4JPL Sentry16342048-2115410.00018646074-4.89-5.220JPL: Computed at 08:01 today Pacific time based on 48 observations spanning 8.9970 days (2018-Apr-12.31705 to 2018-Apr-21.31409). Diameter approximately 0.013 km. from weighted mean H=27.01.
2018 GG4JPL Sentry16342058-207022.6775e-07-6.96-7.100JPL: Computed at 07:52 today Pacific time based on 32 observations spanning 7.9266 days (2018-Apr-13.43759 to 2018-Apr-21.36421). Diameter approximately 0.019 km. from weighted mean H=26.24.
2018 GL2JPL Sentry16342050-209379.92041e-06-4.68-4.730JPL: Computed at 07:50 today Pacific time based on 60 observations spanning 10.098 days (2018-Apr-11.23475 to 2018-Apr-21.33321). Diameter approximately 0.049 km. from weighted mean H=24.20.
2018 GE2JPL Sentry16342054-2117949.6215444e-05-5.28-5.910JPL: Computed at 08:00 today Pacific time based on 88 observations spanning 10.859 days (2018-Apr-10.40973 to 2018-Apr-21.26852). Diameter approximately 0.013 km. from weighted mean H=27.02.

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 21 April '18

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

2212Generated Traffic Report
2004Grabbed MPEC 2018-H61 - 2018 HT - see above
1932Grabbed MPEC 2018-H57 - 2018 HQ - see above
Grabbed MPEC 2018-H58 - 2018 HR - see above
Grabbed MPEC 2018-H59 - 2018 HU - see above
Grabbed MPEC 2018-H60 - 2018 HS - see above
1634Noted that JPL Sentry has updated its 2018 GA5 risk assessment - see above
Noted that JPL Sentry has updated its 2018 GE2 risk assessment - see above
Noted that JPL Sentry has updated its 2018 GG4 risk assessment - see above
Noted that JPL Sentry has updated its 2018 GL2 risk assessment - see above
Noted that JPL Sentry has updated its 2018 GR4 risk assessment - see above
Grabbed MPEC 2018-H56 - Daily Orbit Update - see above