Contents on 31 December '11
- IAU Minor Planet Center
- Observers -- fourteen observers
- Impact Risk Monitoring -- one object
- Consolidated Risk Tables - the CRT page (archive)
Of 425 risk-listed objects, 26 have had news in the last 31 days. Updated at 1935 UTC on 31 Dec.
- Earth's Busy Neighborhood close passer Traffic Report
Five objects are known to be within ten LD of Earth today. Updated at 2019 UTC on 31 Dec.
- Ephemerides for risk-rated & nearby objects + potential mission destinations
- News image catalog
- News old archive & Small Objects Archive
- Object Links - mainly for radar targets & close passers - updated 20 Dec.
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. And use the all-up news archive to access news from any time since A/CC began in early 2002. To keep track of what's new each day, watch the Chronology section.
NEOCP Activity on 31 December '11
The MPC's NEO Confirmation Page has 23 listings
When last checked at 2357 UTC today, the Minor Planet Center's Near Earth Object discovery Confirmation Page (NEOCP) had 23 objects listed. Of these, fifteen were "one nighters." So far The Tracking News has counted a total of 48 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 31 December '11
Minor Planet Electronic Circulars
As of last check at 2357 UTC, there have been five MPECs posted today from the International Astronomical Union's Minor Planet Center in Cambridge, Massachusetts. No Daily Orbit Update DOU MPEC has been posted yet, so visit the MPC Status Page for possible explanation.
- MPEC 2011-Y67 time-stamped "16:51 UT" - 2011 YB40 - see below
- MPEC 2011-Y68 time-stamped "16:53 UT" - 2011 YC40 - see below
- MPEC 2011-Y69 time-stamped "16:55 UT" - 2011 YD40 - see below
- MPEC 2011-Y70 time-stamped "16:57 UT" - 2011 YE40 - see below
- MPEC 2011-Y71 time-stamped "17:21 UT" - 2011 YH40
MPEC 2011-Y71 - "17:21 UT" - 2011 YH40
- K11Y40H 2011 YH40 (small asteroid, Earth MOID=4.8 LD, H=22.4 ~112m, close passer) from the Catalina Sky Survey (CSS) (Dec. 29.42-47p8 & 31.43-44p4), the Spacewatch 1.8m telescope (Dec. 29.46-47p3), Schiaparelli Obs. (Dec. 29.84-86p3), Great Shefford Obs. (Dec. 29.99p3), Doc Greiner Research Obs. Rancho Hildalgo (DGRO-RH) (Dec. 30.17-18p3), Farra d'Isonzo Obs. (Dec. 31.05-06p2), and Moriyama Obs. (Dec. 31.54p2)
MPEC 2011-Y70 - "16:57 UT" - 2011 YE40
- K11Y40E 2011 YE40 (small asteroid, Earth MOID=8.9 LD, H=24.9 ~35m, close passer) from LINEAR (Dec. 30.13-19p5), CSS (Dec. 31.31-33p6), and Sabino Canyon Obs. (Dec. 31.36-37p3)
MPEC 2011-Y69 - "16:55 UT" - 2011 YD40
- K11Y40D 2011 YD40 (H=21.0 ~214m) from the Mt. Lemmon Survey (MLS) (Dec. 29.41-43p4 at V=20.7-22.4, 30.48p4 at V=21.1-22.1 & 31.48p2 at V=21.2-5), Spacewatch 1.8m (Dec. 29.50p3), and Tim Lister via Faulkes Telescope North (Dec. 29.50-51p9)
MPEC 2011-Y68 - "16:53 UT" - 2011 YC40
- K11Y40C 2011 YC40 (risk-listed, Earth MOID=0.3 LD, H=29.7 ~4m, close passer) from MLS (Dec. 29.27-29p7 & 30.32p4) and Sabino Canyon Obs. (Dec. 29.33p2)
MPEC 2011-Y67 - "16:51 UT" - 2011 YB40
Observers on 31 December '11
Fourteen observers appear in today's MPECs.
|Code||Observer / observatory|
|300||Bisei Spaceguard Center in Japan, 1 in MPEC 2011-Y67 -- 2011 YB40|
|703||Catalina Sky Survey (CSS) in Arizona, 3 in MPECs 2011-Y67, 2011-Y70 & 2011-Y71 -- 2011 YH40, 2011 YE40, 2011 YB40|
|G48||Doc Greiner Research Obs. Rancho Hildalgo in New Mexico, 1 in MPEC 2011-Y71 -- 2011 YH40|
|595||Farra d'Isonzo Obs. in Italy, 2 in MPECs 2011-Y67 & 2011-Y71 -- 2011 YH40, 2011 YB40|
|F65%||Tim Lister in southern California via Faulkes Telescope North in Hawaii, 1 in MPEC 2011-Y69 -- 2011 YD40|
|J95||Great Shefford Obs. in England, 1 in MPEC 2011-Y71 -- 2011 YH40|
|C32||Ka-Dar Obs. TAU Station in Russia, 1 in MPEC 2011-Y67 -- 2011 YB40|
|704||LINEAR in New Mexico, 1 in MPEC 2011-Y70 -- 2011 YE40|
|900||Moriyama Obs. in Japan, 1 in MPEC 2011-Y71 -- 2011 YH40|
|G96||Mt. Lemmon Survey (MLS) in Arizona, 2 in MPECs 2011-Y68 & 2011-Y69 -- 2011 YD40, 2011 YC40|
|854||Sabino Canyon Obs. in Arizona, 2 in MPECs 2011-Y68 & 2011-Y70 -- 2011 YE40, 2011 YC40|
|H36||Sandlot Obs. in Kansas, 1 in MPEC 2011-Y67 -- 2011 YB40|
|204||Schiaparelli Obs. in Italy, 1 in MPEC 2011-Y71 -- 2011 YH40|
|291||Spacewatch 1.8m telescope in Arizona, 3 in MPECs 2011-Y67, 2011-Y69 & 2011-Y71 -- 2011 YH40, 2011 YD40, 2011 YB40|
|For a list of all participating observatories that have Web addresses, see A/CC's Observatory Links page.|
Impact Risk Monitoring on 31 December '11
Notes for Today's Latest Risk Assessments
|2011 YC40||JPL Sentry||1908||2028-2050||6||3.4e-06||-7.33||-7.41||0||JPL: "Analysis based on 13 observations spanning 1.0493 days (2011-Dec-29.27153 to 2011-Dec-30.32086)." Diameter approximately 0.004 km. from mean, weighted H=29.7.|
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 31 December '11
Times are UTC for when items were noted or added by The Tracking News.
|1908||Noted that JPL Sentry has posted 2011 YC40 as an impact risk - see above|
|1735||Grabbed MPEC 2011-Y71 - 2011 YH40 - see above|
|1706||Grabbed MPEC 2011-Y67 - 2011 YB40 - see above|
Grabbed MPEC 2011-Y68 - 2011 YC40 - see above
Grabbed MPEC 2011-Y69 - 2011 YD40 - see above
Grabbed MPEC 2011-Y70 - 2011 YE40 - see above