Contents  on 2 June '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 2 June '18

One object reported inside ten LD

One planetesimal is reported inside ten lunar distances (LD) of Earth today. 2018 KN2 is outbound from 8.60 to 9.95 LD.

Neighborhood Traffic
Earth passage I D ~Size Distance today  Inside ten LD Notes
6.10 LD May 29 2018 KN2 27 m  8.60 to 9.95 LD May 25 - tomorrow
Approaching (sorted by 10-LD bubble entry date)
5.56 LD June 10 2018 EJ4 186 m  12.19 from 13.44 LD June 4 - 16 radar/NHATS target - DOU
8.96 LD June 11 2015 DP155 162 m  12.09 from 12.76 LD June 6 - 15 NHATS target - DOU

This report was generated at 2040 UTC with the recovery of dim and distant risk-listed 2017 TA6 in today's DOU MPEC along with first follow-up to the recovery of distant 2015 BL311 and continuing follow-up for approaching objects 2018 EJ4 and 2015 DP155. We also note that yesterday's DOU belatedly announced the discovery of 2018 HU3, which flew past us at 2.10 LD on April 25th.

<< Reading:  The Catalina Sky Survey (CSS) overnight caught an inbound extreme close passer, if not impactor (above southern Asia) -- temporary designation ZLAF9B2. See Bill Gray's first alert on the Minor Planet Mailing List (MPML) and follow-on thread. In that thread, observer Peter Birtwhistle questioned "this one surviving perigee" -- a nice, quiet way to say it might hit Earth.
        The MPML has had some other interesting conversations recently, including the discovery of "the largest plutino discovered in 13 years" -- see 2017 OF69 (MPEC), and a discussion about individual vs. team asteroid discoveries and giving credit where due.
        JPL has news items about how the final stretch of the Dawn mission is about to begin after lowering its orbit to less than 50 km. over 1 Ceres, and about thermal data provided by the NEOWISE mission for more than a hundred asteroids.

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. "Distant" is used here to describe objects that have come within ten LD since A/CC began these traffic reports (2007) but are not so close now. 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 2 June '18

The MPC's NEO Confirmation Page has 8 listings

When last checked at 2358 UTC today, the Minor Planet Center's Near Earth Object discovery Confirmation Page (NEOCP) had eight objects listed. Of these, four 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 2 June '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 2 June '18 >>  MPEC 2018-L02 - "12:02 UT" - Daily Orbit Update

Observers  on 2 June '18

Twelve observers appear in today's MPEC.

CodeObserver / observatory
T08ATLAS Mauna Loa in Hawaii, 3 in MPEC 2018-L02 -- 2015 DP155, 138847, 9856
K46Bamberg Obs. in Germany, 1 in MPEC 2018-L02 -- 1627
X74Campo dos Amarais Obs., 1 in MPEC 2018-L02 -- 96189
W84DECam in Chile, 1 in MPEC 2018-L02 -- 2017 TA6
W841program code 1 via DECam in Chile, 1 in MPEC 2018-L02 -- 2018 AM12
K38M57 Obs. in Italy, 1 in MPEC 2018-L02 -- 2018 JE1
I41Palomar Transient Factory (PTF) in southern California, 2 in MPEC 2018-L02 -- 53789, 337228
D29Purple Mtn. Obs. Xuyi Station in China, 2 in MPEC 2018-L02 -- 190161, 4183
691Spacewatch 0.9m telescope in Arizona, 8 in MPEC 2018-L02 -- 2018 KK2, 2018 KG1, 2018 JQ1, 2018 JL, 2018 JE5, 2018 HJ, 2015 BL311, 2014 WO7
291Spacewatch 1.8m telescope in Arizona, 6 in MPEC 2018-L02 -- 2018 KK1, 2018 KD1, 2018 KC2, 2018 KB1, 2018 JD5, 2018 FJ4
C36Starry Wanderer Obs. in Belarus, 1 in MPEC 2018-L02 -- 2018 EJ4
I52Steward Obs. Mt. Lemmon Station in Arizona, 26 in MPEC 2018-L02 -- 2018 KV, 2018 KU1, 2018 KQ1, 2018 KM2, 2018 KM1, 2018 KL2, 2018 KL, 2018 KH1, 2018 KH, 2018 KG1, 2018 KF3, 2018 KD1, 2018 KC3, 2018 JY1, 2018 JV2, 2018 JS2, 2018 JS1, 2018 JQ1, 2018 JP1, 2018 JL, 2018 JG2, 2018 JE5, 2018 JE1, 2018 JD2, 2018 JC3, 2018 GA5
T12UH/Tholen NEO Follow-Up 2.24m Telescope in Hawaii, 1 in MPEC 2018-L02 -- 2018 BL3
For a list of all participating observatories that have Web addresses, see A/CC's Observatory Links page.

Impact Risk Monitoring  on 2 June '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
2017 TA6JPL Sentry1600R E M O V E DJPL: Risk listing removed at 1407 UTC today

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 2 June '18

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

2040Generated Traffic Report
1600Noted that JPL Sentry has removed 2017 TA6 as an impact risk - see above
Grabbed MPEC 2018-L02 - Daily Orbit Update - see above