Contents  on 3 January '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 3 January '18

Three objects reported inside ten LD

Three minor objects are known to be traveling less than ten lunar distances (LD) from Earth today. Nearest is 2017 YD7, which comes its closest to our world this time around, reaching 4.73 LD at 0039 UTC.

Earth passage I D ~Size Distance today  Inside ten LD Notes
1.93 LD Dec. 24 2017 YS1 6 m  7.07 to 7.76 LD Dec. 11 - Jan. 7 NHATS target
4.73 LD today 2017 YD7 12 m  4.73 LD Dec. 30 - Jan. 6 NHATS target, Earth closest at 0039 UTC
7.74 LD Dec. 30 2017 YU1 20 m  9.98 to 11.14 LD Dec. 26 - today NHATS target, exits ten LD
Approaching (sorted by 10-LD bubble entry date)
3.7   LD Feb. 24* 2017 DR109 10 m  104.5 from 107.3 LD Feb. 18 - March 1 EPU +/- 30 mins.*, NHATS target
3.76 LD March 7 2017 VR12 272 m  84.25 from 85.71 LD Feb. 28 - March 13 radar/NHATS target
* EPU = Earth passage uncertainty

This report was generated at 1652 UTC.

Reading:  Quartz has a nifty little article today, "How far is the Earth from the moon? Take a look yourself." As the author shows, the perspective of the photo from OSIRIS-REx makes the Earth and Moon look about a third closer than they actually are, but clearly there's plenty of empty space out there for small rocks to quietly pass by or between. See this for more about the picture.

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 3 January '18

The MPC's NEO Confirmation Page has 39 listings

When last checked at 2358 UTC today, the Minor Planet Center's Near Earth Object discovery Confirmation Page (NEOCP) had 39 objects listed. Of these, twelve 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 3 January '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 3 Jan. '18 >>  MPEC 2018-A12 - "13:04 UT" - Daily Orbit Update

Observers  on 3 January '18

Twelve observers appear in today's MPEC.

CodeObserver / observatory
T05ATLAS Haleakala in Hawaii, 12 in MPEC 2018-A12 -- 96590, 507366, 475967, 36284, 337228, 302311, 281365, 17511, 163696, 143992, 6053, 1864
T08ATLAS Mauna Loa in Hawaii, 8 in MPEC 2018-A12 -- 2009 QL8, 53110, 496818, 415029, 333888, 162011, 1980, 1627
073Bucharest Obs. in Romania, 1 in MPEC 2018-A12 -- 1999 AF4
160Castelmartini Obs. in Italy, 3 in MPEC 2018-A12 -- 2017 WX12, 504887, 438430
J04ESA Optical Ground Station in the Canary Islands, 1 in MPEC 2018-A12 -- 2015 YD18
H15ISON New Mexico Obs. in New Mexico, 1 in MPEC 2018-A12 -- 3122
Z22MASTER IAC Obs. in the Canary Islands, 1 in MPEC 2018-A12 -- 333888
Z80Northolt Branch Obs. in England, 1 in MPEC 2018-A12 -- 3122
F51Pan-STARRS 1 (PS1) in Hawaii, 3 in MPEC 2018-A12 -- 96189, 66251, 1036
V78Spirit Marsh Obs. in Minnesota, 1 in MPEC 2018-A12 -- 3122
W34Squirrel Valley Obs. in North Carolina, 1 in MPEC 2018-A12 -- 361071
C51WISE in Earth polar orbit, 4 in MPEC 2018-A12 -- 2017 UR7, 2004 CL1, 96189, 322763
For a list of all participating observatories that have Web addresses, see A/CC's Observatory Links page.

Impact Risk Monitoring  on 3 January '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 YE8NEODyS07342110-211336.68e-08-7.67-8.140NEODyS: "Based on 20 optical observations (of which 4 are rejected as outliers) from 2017-12-29.286 to 2017-12-31.435."

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 3 January '18

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

1652Generated Traffic Report
1644Grabbed MPEC 2018-A12 - Daily Orbit Update - see above
0734Noted that NEODyS has posted 2017 YE8 as an impact risk - see above