162173 Ryugu (1999 JU3) imaged from arriving JAXA Hayabusa2 mission.
 Credit: JAXA, Univ. of Tokyo & collaborators.

JAXA's Hayabusa2 mission has arrived at its destination, asteroid 162173 Ryugu (1999 JU3), seen here from a distance of about 40 km. Image credit: JAXA, Univ. of Tokyo & collaborators.

Contents  on 26 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 26 June '18

Three objects reported inside ten LD

There are three minor objects reported moving inside ten lunar distances (LD) of our home world today. Nearest is risk-listed 2018 MX4, inbound from 6.35 to 5.68 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
2.19 LD June 18 2018 MC7 23 m  9.10 to 10.22 LD June 9 - 26 NHATS target, exits ten LD, risk - DOU
5.51 LD tomorrow 2018 MX4 14 m  5.68 from 6.35 LD June 23 - July 2 risk
6.01 LD June 29 2018 LR3 19 m  6.46 from 6.81 LD June 20 - July 8 NHATS target, risk - DOU
2.8   LD July 4* 2018 MB7 60 m  19.4 from 22.0 LD June 30 - July 8 Earth passage uncertainty +/- 40 mins.*

This report was generated at 1939 UTC with follow-up in today's DOU MPEC for departed objects 2018 MG7 and 68347 2001 KB67, distant 450894 2008 BT18, and three risk-listed objects: inbound 2018 LR3, outbound 2018 MC7, and departed 2018 LM, plus astrometry from a couple weeks ago for risk-listed intruder 2018 LV3.

<< Reading:  JAXA's Hayabusa2 mission has arrived at its destination. See image and links above.
        Phil Plait has a report on how the fairly recent impact of a small object on Mars caused an interesting avalanche. And researchers have announced confirmation of an impact structure in Finland.
        A preprint posted yesterday outlines how NASA's New Horizons extended mission will progress, including the New Year's Day flyby of KBO 486958 2014 MU69, which is expected to produce about 50 Gbits of data that will require 21 months to download. Additional mission extensions in three stages are also proposed, from 2022 through 2035 and beyond.

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 an object that has approached Earth within ten LD since A/CC began these traffic reports eleven years ago but is not currently coming so close. 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 26 June '18

The MPC's NEO Confirmation Page has 24 listings

When last checked at 2154 UTC today, the Minor Planet Center's Near Earth Object discovery Confirmation Page (NEOCP) had 24 objects listed. Of these, eleven were "one nighters." So far The Tracking News has counted a total of 28 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 26 June '18

Minor Planet Electronic Circulars

As of last check at 2156 UTC, there have been three MPECs posted today from the International Astronomical Union's Minor Planet Center in Cambridge, Massachusetts.

MPEC 2018-M100 - "20:50 UT" - 2018 ML8

<< DOU on 26 June '18 >>  MPEC 2018-M99 - "12:03 UT" - Daily Orbit Update

MPEC 2018-M98 - "10:26 UT" - 2018 MK8

Observers  on 26 June '18

A total of 27 observers appear in today's MPECs.

CodeObserver / observatory
E23Arcadia Obs. in New South Wales, 1 in MPEC 2018-M98 -- 2018 MK8
H21Astronomical Research Obs. Westfield in Illinois, 1 in MPEC 2018-M98 -- 2018 MK8
T05ATLAS Haleakala in Hawaii, 13 in MPEC 2018-M99 -- 2017 YE5, 2015 RB82, 2011 GA62, 2005 MF5, 99799, 87311, 65996, 162168, 139345, 7889, 2061, 1627, 719
T08ATLAS Mauna Loa in Hawaii, 1 in MPEC 2018-M99 -- 2018 MG7
073Bucharest Obs. in Romania, 1 in MPEC 2018-M99 -- 13553
U63Burnt Tree Hill Obs., 1 in MPEC 2018-M99 -- 68347
160Castelmartini Obs. in Italy, 1 in MPEC 2018-M98 -- 2018 MK8
703Catalina Sky Survey (CSS) in Arizona, 12 in MPEC 2018-M99 -- 99799, 89959, 511523, 495615, 450894, 189865, 159495, 100085, 6569, 6456, 3691, 2061
807|Robert Holmes in Illinois via Cerro Tololo Inter-American Obs. in Chile, 1 in MPEC 2018-M100 -- 2018 ML8
595Farra d'Isonzo Obs. in Italy, 1 in MPEC 2018-M99 -- 2018 MG7
J81Guirguillano Obs. in Spain, 1 in MPEC 2018-M99 -- 2018 MG7
P93JAXA Space Tracking & Communications Center in Japan, 1 in MPEC 2018-M98 -- 2018 MK8
Z22MASTER IAC Obs. in the Canary Islands, 1 in MPEC 2018-M99 -- 16960
G96Mt. Lemmon Survey (MLS) in Arizona, 2 in MPEC 2018-M99 -- 2018 LF5, 37336
628Mulheim-Ruhr Obs. in Germany, 1 in MPEC 2018-M99 -- 68950
J69North Obs. in England, 1 in MPEC 2018-M99 -- 2018 MG7
Z80Northolt Branch Obs. in England, 1 in MPEC 2018-M99 -- 2017 YE5
C23Olmen Obs. in Belgium, 2 in MPEC 2018-M99 -- 66391, 1627
I41Palomar Transient Factory (PTF) in southern California, 2 in MPEC 2018-M99 -- 2018 GA5, 4257
F51Pan-STARRS 1 (PS1) in Hawaii, 6 in MPECs 2018-M98 & 2018-M99 -- 2018 MK8, 2018 LQ2, 2017 BW30, 86666, 504711, 219021
F52Pan-STARRS 2 (PS2) in Hawaii, 3 in MPEC 2018-M99 -- 2018 MS6, 65996, 2061
691Spacewatch 0.9m telescope in Arizona, 5 in MPECs 2018-M98 & 2018-M99 -- 2018 MK8, 2018 MD7, 2018 MC7, 2018 LS2, 2014 OY1
I52Steward Obs. Mt. Lemmon Station in Arizona, 1 in MPEC 2018-M98 -- 2018 MK8
381Tokyo-Kiso Obs. in Japan, 1 in MPEC 2018-M99 -- 2018 LV3
T12UH/Tholen NEO Follow-Up 2.24m Telescope in Hawaii, 5 in MPECs 2018-M99 & 2018-M100 -- 2018 MW6, 2018 ML8, 2018 MD7, 2018 LR3, 2018 LM
L01Visnjan Obs., 1 in MPEC 2018-M98 -- 2018 MK8
C51WISE in Earth polar orbit, 3 in MPECs 2018-M99 & 2018-M100 -- 2018 ML8, 444193, 152637
For a list of all participating observatories that have Web addresses, see A/CC's Observatory Links page.

Impact Risk Monitoring  on 26 June '18

Summary Risk Table for Risk Assessments Updated Today   (last checks: NEODyS at 2152 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 MD7JPL Sentry1530R E M O V E DJPL: Risk listing removed at 1415 UTC today
2018 MC7JPL Sentry15302060-2115470.000309890839-4.07-4.230JPL: Computed at 07:12 today Pacific time based on 25 observations spanning 4.9961 days (2018-Jun-21.39443 to 2018-Jun-26.39055). Diameter approximately 0.023 km. from weighted mean H=25.84.
2018 MW6JPL Sentry1530R E M O V E DJPL: Risk listing removed at 1403 UTC today
2018 LV3JPL Sentry15302061-206111.719e-07-7.46-7.460JPL: Computed at 07:01 today Pacific time based on 38 observations spanning 2.7990 days (2018-Jun-11.38233 to 2018-Jun-14.18134). Diameter approximately 0.017 km. from weighted mean H=26.55.
2018 LR3JPL Sentry15302077-210033.0044e-06-6.44-6.600JPL: Computed at 07:07 today Pacific time based on 51 observations spanning 14.921 days (2018-Jun-10.32538 to 2018-Jun-25.246552). Diameter approximately 0.019 km. from weighted mean H=26.25.
2018 LMJPL Sentry16052112-211631.5244e-06-6.42-6.740JPL #2 for the day: Computed at 08:38 today Pacific time based on 90 observations spanning 21.026 days (2018-Jun-04.25437 to 2018-Jun-25.280771). Diameter approximately 0.030 km. from weighted mean H=25.23.

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 26 June '18

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

2133Grabbed MPEC 2018-M100 - 2018 ML8 - see above
1939Generated Traffic Report
1605Noted that JPL Sentry has updated its 2018 LM risk assessment - see above
1530Noted that JPL Sentry has updated its 2018 LM risk assessment - see above
Noted that JPL Sentry has updated its 2018 LR3 risk assessment - see above
Noted that JPL Sentry has posted 2018 LV3 as an impact risk - see above
Noted that JPL Sentry has updated its 2018 MC7 risk assessment - see above
Noted that JPL Sentry has removed 2018 MD7 as an impact risk - see above
Noted that JPL Sentry has removed 2018 MW6 as an impact risk - see above
Grabbed MPEC 2018-M98 - 2018 MK8 - see above
Grabbed MPEC 2018-M99 - Daily Orbit Update - see above