Contents  on 28 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 28 April '18

One object reported inside ten LD

One planetesimal is reported within ten lunar distances (LD) of Earth today. Risk-listed intruder 2018 HW1 is outbound from from 6.56 to 7.62 LD.

Neighborhood Traffic
Earth passage I D ~Size Distance today  Inside ten LD Notes
0.89 LD April 21 2018 HW1 22 m  6.56 to 7.62 LD April 12 - May 1 intruder, NHATS target, risk
Approaching (sorted by 10-LD bubble entry date)
6.2   LD May 8* 2016 JQ5 8 m  22.6 from 24.9 LD May 4 - 11 EPU +/- 14.00 hours*
9.65 LD May 7 1999 FN19 112 m  14.54 from 15.50 LD May 5 - 9 radar/NHATS target
6.48 LD May 9 388945 2008 TZ3 282 m  22.33 from 24.33 LD May 5 - 13
9.50 LD May 29 68347 2001 KB67 371 m  96.13 from 99.70 LD May 28 - 30 radar target
5.56 LD June 10 2018 EJ4 186 m  57.28 from 58.52 LD June 4 - 16 radar/NHATS target
8.96 LD June 11 2015 DP155 162 m  39.69 from 40.41 LD June 6 - 15 NHATS target
* EPU = Earth passage uncertainty

This report was generated at 1820 UTC with follow-up in today's DOU MPEC for departed 2018 HL1.

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 28 April '18

The MPC's NEO Confirmation Page has 17 listings

When last checked at 2358 UTC today, the Minor Planet Center's Near Earth Object discovery Confirmation Page (NEOCP) had seventeen objects listed. Of these, six were "one nighters."

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 '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-H99 - "21:31 UT" - 2007 CM26 = 2018 EY2

Id. R. Weryk

<< DOU on 28 Apr. '18 >>  MPEC 2018-H98 - "12:04 UT" - Daily Orbit Update

Observers  on 28 April '18

Eleven observers appear in today's MPECs.

CodeObserver / observatory
703Catalina Sky Survey (CSS) in Arizona, 3 in MPEC 2018-H98 -- 184990, 152637, 1627
006Fabra Obs. in Spain, 2 in MPEC 2018-H98 -- 2013 US3, 444193
P93JAXA Space Tracking & Communications Center in Japan, 1 in MPEC 2018-H98 -- 212359
Z43Landehen Obs., 3 in MPEC 2018-H98 -- 2016 JP, 2013 US3, 194126
G96Mt. Lemmon Survey (MLS) in Arizona, 3 in MPEC 2018-H98 -- 2014 JC31, 24761, 15745
F51Pan-STARRS 1 in Hawaii, 1 in MPEC 2018-H99 -- 2007 CM26
K81PMPHR Obs., 1 in MPEC 2018-H98 -- 138847
C95SATINO-1 in France, 1 in MPEC 2018-H98 -- 2017 WH14
W885M. Kumrucu-Lohmiller in Massachusetts via Chile Obs. in Chile, 1 in MPEC 2018-H98 -- 2018 FQ5
C51WISE in Earth polar orbit, 2 in MPEC 2018-H98 -- 463664, 288807
E08Wobblesock Obs. in New South Wales, 2 in MPEC 2018-H98 -- 2018 HL1, 2018 FN4
For a list of all participating observatories that have Web addresses, see A/CC's Observatory Links page.

Impact Risk Monitoring  on 28 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.





Notes for Today's Latest Risk Assessments
2018 EY2JPL Sentry2230R E M O V E DJPL: Risk listing removed at 1206 UTC March 13th

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 '18

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

2230Noted that JPL Sentry has removed 2018 EY2 as an impact risk - see above
2139Grabbed MPEC 2018-H99 - 2007 CM26 = 2018 EY2 - see above
1820Generated Traffic Report
1630Grabbed MPEC 2018-H98 - Daily Orbit Update - see above