Contents  on 28 April '17

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 28 April '17

Eight objects reported inside ten LD

Eight objects are reported passing inside ten lunar distances (LD) of Earth today. Nearest is newly announced risk-listed intruder 2017 HG4, which recedes from 4.79 to 5.59 LD.

Earth passage I D ~Size Distance Today  Notes
0.33 LD April 232017 HV2 6 m  8.52 to 10.59 LD exits ten LD, intruder
0.61 LD April 222017 HG4 10 m  4.79 to 5.59 LD NEW, intruder, risk - MPEC, DOU
2.55 LD April 262017 HY3 28 m  6.95 to 10.61 LD exits ten LD, risk - DOU
3.17 LD April 202017 HU2 23 m  7.18 to 7.99 LD DOU
3.24 LD April 242017 HY 11 m  6.78 to 8.28 LD
3.59 LD April 242017 HB1 19 m  6.79 to 8.19 LD
6.12 LD April 302017 HU3 28 m  6.50 from 7.42 LD
9.18 LD yesterday2017 HW2 16 m  9.18 to 9.44 LD DOU
7.93 LD May 292017 CS 446 m  < 10 LD May 26, radar target

This report was generated at 1804 UTC with the discovery of 2017 HG4 and with follow-up in today's DOU MPEC for that and three other objects active in the traffic table here. The DOU also has follow-up for departed objects 2017 HG1 and radar target 2014 JO25 plus astrometry from March for 2017 FL101.

Notes: Ten times the distance to the Moon (ten LD) has no astronomical importance but is a useful boundary for reporting on transient natural objects that approach the actually significant 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 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 28 April '17

The MPC's NEO Confirmation Page has 63 listings

When last checked at 2358 UTC today, the Minor Planet Center's Near Earth Object discovery Confirmation Page (NEOCP) had 63 objects listed. Of these, 23 were "one nighters." So far The Tracking News has counted a total of 82 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 28 April '17

Minor Planet Electronic Circulars

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

<< DOU on 28 Apr. '17 >>  MPEC 2017-H76 - "11:59 UT" - Daily Orbit Update

MPEC 2017-H75 - "02:29 UT" - 2017 HG4

MPEC 2017-H74 - "02:25 UT" - 2017 HE4

MPEC 2017-H73 - "02:19 UT" - 2017 HF4

Observers  on 28 April '17

A total of 21 observers appear in today's MPECs.

CodeObserver / observatory
H21Astronomical Research Obs. Westfield in Illinois, 10 in MPECs 2017-H74 & 2017-H76 -- 2017 HY3, 2017 HU2, 2017 HG4, 2017 HG1, 2017 HE4, 2017 FO128, 2017 FK90, 2017 DO36, 277279, 143404
T05ATLAS Haleakala in Hawaii, 6 in MPEC 2017-H76 -- 2016 JP, 2005 GB120, 484517, 220124, 152931, 11398
807|Robert Holmes in Illinois via Cerro Tololo Inter-American Obs. (CTIO) in Chile, 4 in MPEC 2017-H76 -- 2017 HU2, 2017 HF4, 2017 FS101, 2016 XH1
850Cordell-Lorenz Obs. in Tennessee, 1 in MPEC 2017-H76 -- 2014 JO25
822Cordoba Obs. in Argentina, 1 in MPEC 2017-H76 -- 90075
I39Cruz del Sur Obs. in Argentina, 1 in MPEC 2017-H76 -- 2014 JO25
K87Dettelbach Vineyard Obs., 1 in MPEC 2017-H76 -- 2017 FL101
Q60ISON Siding Spring Obs. in New South Wales, 2 in MPEC 2017-H76 -- 162149, 1980
W87LCOGT Cerro Tololo C in Chile, 1 in MPEC 2017-H76 -- 2014 JO25
474Mt. John Obs. in New Zealand, 3 in MPECs 2017-H74 & 2017-H76 -- 2017 HU2, 2017 HU, 2017 HE4
G96Mt. Lemmon Survey (MLS) in Arizona, 7 in MPECs 2017-H74, 2017-H75 & 2017-H76 -- 2017 HG4, 2017 HE4, 480984, 39796, 339492, 159560, 136635
0895program code 5 via Nikolaev Obs. in the Ukraine, 1 in MPEC 2017-H76 -- 2014 JO25
Z80Northolt Branch Obs. in England, 3 in MPEC 2017-H76 -- 2016 WO1, 456651, 260141
C23Olmen Obs. in Belgium, 1 in MPEC 2017-H76 -- 2014 JO25
F51Pan-STARRS 1 (PS1) in Hawaii, 29 in MPECs 2017-H73, 2017-H75 & 2017-H76 -- 2017 HG4, 2017 HG2, 2017 HF4, 2017 GW6, 2017 GU6, 2017 GQ4, 2017 GO6, 2017 FM63, 2017 FK128, 2016 WO1, 2016 VV3, 2015 FF37, 2013 GU38, 2012 QF49, 2009 JK1, 2004 RN335, 2002 GK8, 96631, 90373, 65803, 483459, 363305, 276468, 242187, 164211, 163760, 138095, 4015, 1917
D29Purple Mtn. Obs. Xuyi Station in China, 2 in MPEC 2017-H76 -- 484517, 220124
033Schwarzschild Obs. in Germany, 1 in MPEC 2017-H74 -- 2017 HE4
I93St. Pardon de Conques Obs. in France, 1 in MPEC 2017-H75 -- 2017 HG4
I52Steward Obs. Mt. Lemmon Station in Arizona, 1 in MPEC 2017-H74 -- 2017 HE4
926Tenagra II Obs. in Arizona, 3 in MPECs 2017-H74 & 2017-H76 -- 2017 HY3, 2017 HW2, 2017 HE4
T12UH/Tholen NEO Follow-Up 2.24m Telescope in Hawaii, 3 in MPECs 2017-H73 & 2017-H76 -- 2017 HT2, 2017 HF4, 2014 JO25
For a list of all participating observatories that have Web addresses, see A/CC's Observatory Links page.

Impact Risk Monitoring  on 28 April '17

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.





Notes for Today's Latest Risk Assessments
2017 HG4JPL Sentry16002034-2115161.3576727e-05-6.34-6.960JPL #2 for the day: Computed at 08:50 today Pacific time based on 25 observations spanning 1.8289 days (2017-Apr-26.26272 to 2017-Apr-28.091582). Diameter approximately 0.010 km. from weighted mean H=27.66.
2017 HY3JPL Sentry15302024-202412.130e-09-7.87-7.870JPL: Computed at 08:08 today Pacific time based on 77 observations spanning 2.1094 days (2017-Apr-24.37009 to 2017-Apr-26.47947). Diameter approximately 0.028 km. from weighted mean H=25.43.
2017 HT2JPL Sentry15302031-2116525.5404596e-06-1.87-2.210JPL: Computed at 08:06 today Pacific time based on 40 observations spanning 7.1996 days (2017-Apr-20.30727 to 2017-Apr-27.506844). Diameter approximately 0.731 km. from weighted mean H=18.32.
2017 FO128JPL Sentry15302104-210939.683e-08-5.94-6.240JPL: Computed at 08:16 today Pacific time based on 89 observations spanning 25.655 days (2017-Mar-30.26183 to 2017-Apr-24.916408). Diameter approximately 0.110 km. from weighted mean H=22.44.

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 28 April '17

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

1804Generated Traffic Report
1600Noted that JPL Sentry has updated its 2017 HG4 risk assessment - see above
1530Noted that JPL Sentry has updated its 2017 FO128 risk assessment - see above
Noted that JPL Sentry has updated its 2017 HT2 risk assessment - see above
Noted that JPL Sentry has updated its 2017 HY3 risk assessment - see above
Grabbed MPEC 2017-H76 - Daily Orbit Update - see above
0532Noted that JPL Sentry has posted 2017 HG4 as an impact risk - see above
0300Grabbed MPEC 2017-H73 - 2017 HF4 - see above
Grabbed MPEC 2017-H74 - 2017 HE4 - see above
Grabbed MPEC 2017-H75 - 2017 HG4 - see above