Contents on 25 September '18
- Traffic Report -- five objects
- IAU Minor Planet Center
- Observers -- seven observers
- Impact Risk Monitoring -- two objects
Asteroid/Comet Connection (A/CC) Resources:
- Consolidated Risk Tables - the CRT page
Of 970 risk-listed objects, 43 have had news in the last 31 days. Updated at 1602 UTC on 25 Sept.
- Ephemerides for risk-listed objects & close passers
- News archive (old) & news image catalog (discontinued)
- Object Links - mainly for radar targets & close passers (mostly discontinued)
- Observing Campaigns (old)
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 25 September '18
Five objects reported inside ten LD
Five minor objects are reported within ten lunar distances (LD) of Earth today. Nearest is 2018 RQ1, which moves outward from 4.06 to 4.12 LD.
|Neighborhood Traffic - sorted by Earth passage distance, grouped by 2.41, 5.0 & 10.0 LD boundaries|
|Earth passage||I D||~Size||Distance today||Inside ten LD||Notes|
|4.06 LD yesterday||2018 RQ1||51 m||4.06 to 4.12 LD||Sept. 11 - Oct. 8||NHATS target|
|4.30 LD yesterday||2018 ST1||32 m||4.73 to 6.35 LD||Sept. 20 - 27||NEW, risk - MPEC|
|6.51 LD Sept. 27||2018 SS1||65 m||7.46 from 9.45 LD||yesterday - Sept. 29|
|6.80 LD Sept. 27||2018 SM1||93 m||7.04 from 7.46 LD||Sept. 21 - Oct. 3||NHATS target|
|8.57 LD Sept. 22||2018 RH6||11 m||9.02 to 9.53 LD||Sept. 19 - 26||NHATS target|
This report was generated at 1752 UTC with the discovery of risk-listed outbound 2018 ST1 (MPEC).
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 25 September '18
The MPC's NEO Confirmation Page has 25 listings
When last checked at 2358 UTC today, the Minor Planet Center's Near Earth Object discovery Confirmation Page (NEOCP) had 25 objects listed. Of these, ten were "one nighters." So far The Tracking News has counted a total of 27 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 25 September '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-S60 time-stamped "10:16 UT" - 2018 ST1 - see below
- MPEC 2018-S61 time-stamped "12:24 UT" - Daily Orbit Update
- K18P09L 2018 PL9 (Q=5.494 AU, arc=45 days, H=19.2 ~490m) from WISE (Sept. 21.62p1 & 21.75p1)
- 37336 37336 2001 RM from WISE (Sept. 23.60p2, 23.73p1, 24.26p1, 24.32p1 & 24.39p1)
MPEC 2018-S60 - "10:16 UT" - 2018 ST1
- K18S01T 2018 ST1 (risk listed, Earth MOID=3.2 LD, H=25.1 ~32m, close passer) was picked up at 0733 UT on 22 Sept. by the Palomar Transient Factory (PTF), observing it at Sept. 22.24-34p11. This detection was confirmed by San Marcello Pistoiese Obs. (Sept. 22.97-99p5), Big Water Obs. (Sept. 23.13-15p7), Great Shefford Obs. (Sept. 23.87-88p5, 24.01-05p4 & 24.91-96p7), Northolt Branch Obs. (Sept. 23.95-97p3), and North Obs. (Sept. 23.97p3).
Observers on 25 September '18
Seven observers appear in today's MPECs.
|Code||Observer / observatory|
|V03||Big Water Obs. in Utah, 1 in MPEC 2018-S60 -- 2018 ST1|
|J95||Great Shefford Obs. in England, 1 in MPEC 2018-S60 -- 2018 ST1|
|J69||North Obs. in England, 1 in MPEC 2018-S60 -- 2018 ST1|
|Z80||Northolt Branch Obs. in England, 1 in MPEC 2018-S60 -- 2018 ST1|
|I41||Palomar Transient Factory in southern California, 1 in MPEC 2018-S60 -- 2018 ST1|
|104||San Marcello Pistoiese Obs. in Italy, 1 in MPEC 2018-S60 -- 2018 ST1|
|C51||WISE in Earth polar orbit, 2 in MPEC 2018-S61 -- 2018 PL9, 37336|
|For a list of all participating observatories that have Web addresses, see A/CC's Observatory Links page.|
Impact Risk Monitoring on 25 September '18
Notes for Today's Latest Risk Assessments
|2018 ST1||NEODyS||1600||2090||1||8.49e-09||-8.32||-8.32||0||NEODyS: "Based on 45 optical observations (of which 3 are rejected as outliers) from 2018-09-22.242 to 2018-09-24.957."|
|2009 FZ4||NEODyS||1600||2022-2116||162||4.73e-07||-6.31||-7.07||0||NEODyS: "Based on 11 optical observations (of which 0 are rejected as outliers) from 2009-03-19.371 to 2009-03-19.970."|
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 25 September '18
Times are UTC for when items were noted or added by The Tracking News.
|1752||Generated Traffic Report|
|1600||Noted that NEODyS has updated its 2009 FZ4 risk assessment - see above|
Noted that NEODyS has posted 2018 ST1 as an impact risk - see above
Grabbed MPEC 2018-S60 - 2018 ST1 - see above
Grabbed MPEC 2018-S61 - Daily Orbit Update - see above