Contents  on 23 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 23 April '18

Five objects reported inside ten LD

There are five Solar-System small bodies reported to be within ten lunar distances (LD) of Earth today. Nearest is intruder 2018 HV, which leaves Earth's sphere of gravitational influence, shooting off from 1.11 to 4.62 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
0.40 LD yesterday 2018 HV 6 m  1.11 to 4.62 LD April 19 - 25 intruder, exits Earth SOI - DOU
4.06 LD April 3 2018 GE 11 m  9.27 to 9.65 LD March 13 - tomorrow NHATS target
7.09 LD April 21 2018 HT 14 m  7.68 to 8.47 LD April 17 - 25
7.99 LD April 21 2018 HN 35 m  8.39 to 9.30 LD April 19 - 24 NHATS target
9.72 LD today 2018 GG4 19 m  9.72 LD yesterday - tomorrow Earth closest at 1628 UTC, risk

This report was generated at 1742 UTC with first follow-up for departed 2018 HU in today's DOU MPEC along with continuing follow-up for approaching objects 2018 EJ4, 2015 DP155, and 388945 2008 TZ3, for outbound intruder 2018 HV, and for departed objects 2018 GP and risk-listed 2018 GE2.

Approaching Traffic - sorted by 10-LD bubble entry date
Earth passage I D ~Size Distance today  Inside ten LD Notes
6.2   LD May 8* 2016 JQ5 8 m  34.4 from 36.8 LD May 4 - 11 EPU +/- 14.00 hours*
9.65 LD May 7 1999 FN19 112 m  19.64 from 20.72 LD May 5 - 9 radar/NHATS target
6.48 LD May 9 388945 2008 TZ3 282 m  32.53 from 34.62 LD May 5 - 13 DOU
9.50 LD May 29 68347 2001 KB67 371 m  114.45 from 118.27 LD May 28 - 30 radar target
5.6   LD June 10* 2018 EJ4 186 m  63.5 from 64.7 LD June 4 - 16 EPU +/- 5 mins.*, radar/NHATS target - DOU
8.96 LD June 11 2015 DP155 162 m  43.25 from 43.95 LD June 6 - 15 NHATS target - DOU
* EPU = Earth passage uncertainty


<< Reading:  NASA/JPL has a news release about the availability of the fourth year of data from the NEOWISE mission. And a science preprint today discusses the formation of 4179Toutatis (1989 AC) based on imagery from the Chinese Chang'e-2 mission as well as radar observation.



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 23 April '18

The MPC's NEO Confirmation Page has 38 listings

When last checked at 2358 UTC today, the Minor Planet Center's Near Earth Object discovery Confirmation Page (NEOCP) had 38 objects listed. Of these, nineteen 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 23 April '18

Minor Planet Electronic Circulars

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


<< DOU on 23 Apr. '18 >>  MPEC 2018-H69 - "12:04 UT" - Daily Orbit Update

Observers  on 23 April '18

Nineteen observers appear in today's MPEC.

CodeObserver / observatory
H21Astronomical Research Obs. Westfield in Illinois, 3 in MPEC 2018-H69 -- 2018 GD, 2018 GA2, 2018 FE2
T05ATLAS Haleakala in Hawaii, 3 in MPEC 2018-H69 -- 85628, 194126, 1627
160Castelmartini Obs. in Italy, 20 in MPEC 2018-H69 -- 2018 GY1, 2018 FQ5, 2018 BY2, 85628, 66251, 498548, 475967, 388945, 374851, 36183, 337084, 25916, 212359, 194126, 184990, 163243, 15745, 14402, 138847, 115052
703Catalina Sky Survey (CSS) in Arizona, 6 in MPEC 2018-H69 -- 2017 BD29, 2015 DP155, 463664, 444193, 337228, 1866
246KLENOT in the Czech Republic, 3 in MPEC 2018-H69 -- 2018 GY1, 2018 GR2, 2018 GJ1
W87LCO Cerro Tololo C in Chile, 1 in MPEC 2018-H69 -- 2018 HV
K38M57 Obs. in Italy, 3 in MPEC 2018-H69 -- 2018 GJ1, 2013 US3, 388945
G96Mt. Lemmon Survey (MLS) in Arizona, 3 in MPEC 2018-H69 -- 2017 SE19, 172034, 4947
I41Palomar Transient Factory (PTF) in southern California, 2 in MPEC 2018-H69 -- 2014 JC31, 212359
A53Peschiera del Garda Obs. in Italy, 1 in MPEC 2018-H69 -- 2018 BY2
K81PMPHR Obs., 1 in MPEC 2018-H69 -- 138847
W885M. Kumrucu-Lohmiller in Massachusetts via Slooh.com Chile Obs. in Chile, 1 in MPEC 2018-H69 -- 162168
Y00SONEAR in Brazil, 1 in MPEC 2018-H69 -- 194126
691Spacewatch 0.9m telescope in Arizona, 14 in MPEC 2018-H69 -- 2018 GZ4, 2018 GX4, 2018 GT4, 2018 GT3, 2018 GQ2, 2018 GJ2, 2018 GH4, 2018 GF4, 2018 GE2, 2018 FW2, 2018 FV4, 2018 EQ4, 2018 EE4, 2013 JY35
291Spacewatch 1.8m telescope in Arizona, 10 in MPEC 2018-H69 -- 2018 HA1, 2018 GW4, 2018 GV5, 2018 GV, 2018 GR4, 2018 GH4, 2018 GE4, 2018 FY4, 2016 CA136, 2015 HF11
C36Starry Wanderer Obs. in Belarus, 1 in MPEC 2018-H69 -- 2018 BY2
I52Steward Obs. Mt. Lemmon Station in Arizona, 23 in MPEC 2018-H69 -- 2018 HU, 2018 HR, 2018 HQ, 2018 HP, 2018 HL, 2018 HK, 2018 HH, 2018 HC, 2018 GZ3, 2018 GY1, 2018 GX, 2018 GW3, 2018 GV5, 2018 GS4, 2018 GR5, 2018 GR1, 2018 GO4, 2018 GJ5, 2018 GJ1, 2018 GH5, 2018 GG5, 2018 GF4, 2018 EJ4
381Tokyo-Kiso Obs. in Japan, 1 in MPEC 2018-H69 -- 2018 GP
I15Wishing Star Obs. in Rhode Island, 2 in MPEC 2018-H69 -- 2018 GY1, 2018 BY2
For a list of all participating observatories that have Web addresses, see A/CC's Observatory Links page.

Impact Risk Monitoring  on 23 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 HA1JPL Sentry15372026-202615.119e-10-6.68-6.680JPL: Computed at 08:20 today Pacific time based on 30 observations spanning 3.8422 days (2018-Apr-19.32466 to 2018-Apr-23.16688). Diameter approximately 0.140 km. from weighted mean H=21.88.
NEODyS15372026-210272.79e-08-5.09-5.20NEODyS: "Based on 27 optical observations (of which 0 are rejected as outliers) from 2018-04-19.325 to 2018-04-22.299."
2018 GA5NEODyS1537R E M O V E D-
2018 GR4JPL Sentry15372048-2115510.000263478131-4.74-5.070JPL: Computed at 08:16 today Pacific time based on 54 observations spanning 10.837 days (2018-Apr-12.31705 to 2018-Apr-23.15402). Diameter approximately 0.013 km. from weighted mean H=27.01.
NEODyS15372048-21181771.24e-04-5.07-5.32n/aNEODyS: "Based on 51 optical observations (of which 1 are rejected as outliers) from 2018-04-12.318 to 2018-04-22.410."
2018 GL2NEODyS15372060-2113155.83e-06-4.92-4.990NEODyS: "Based on 63 optical observations (of which 0 are rejected as outliers) from 2018-04-11.236 to 2018-04-22.439."
2018 GE2JPL Sentry15372057-2117858.40938370000001e-05-5.33-5.910JPL: Computed at 08:19 today Pacific time based on 94 observations spanning 12.771 days (2018-Apr-10.40973 to 2018-Apr-23.18032). Diameter approximately 0.013 km. from weighted mean H=27.03.
NEODyS15372054-21182586.39e-05-5.45-6.05n/aNEODyS: "Based on 92 optical observations (of which 4 are rejected as outliers) from 2018-04-10.411 to 2018-04-22.395."

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 23 April '18

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

1742Generated Traffic Report
1537Noted that NEODyS has removed 2018 GA5 as an impact risk - see above
Noted that JPL Sentry has updated its 2018 GE2 risk assessment - see above
Noted that NEODyS has updated its 2018 GE2 risk assessment - see above
Noted that NEODyS has updated its 2018 GL2 risk assessment - see above
Noted that JPL Sentry has updated its 2018 GR4 risk assessment - see above
Noted that NEODyS has updated its 2018 GR4 risk assessment - see above
Noted that JPL Sentry has updated its 2018 HA1 risk assessment - see above
Noted that NEODyS has posted 2018 HA1 as an impact risk - see above
Grabbed MPEC 2018-H69 - Daily Orbit Update - see above