99942 Apophis radar image from Arecibo 
in Jan. 2005. Credit: Lance Benner.

The best available "picture" of 99942 Apophis (2004 MN4) comes from an hour-long doppler radar session at Arecibo at midnight UTC on 28-29 January 2005 when this object was 74.7 lunar distances (0.192 AU) from Earth. A new paper by Jon Giorgini, et al. has been posted at JPL, "Predicting the Earth encounters of (99942) Apophis" (1.36Mb PDF). It explains how "Arecibo delay-Doppler measurements of (99942) Apophis in 2005 and 2006 resulted in a five standard-deviation trajectory correction to the optically predicted close approach distance to Earth in 2029," and goes on to consider all the uncertainties involved in studying the "small estimated Earth impact probability" that remains for 2036. The report includes looking for encounters with other asteroids (e.g., Apophis comes close to 144898 2004 VD17 in 2034), how to best conduct pre-2029 observations (radar is vital), and, briefly, mitigation possibilities. The paper concludes that, if a deflection effort becomes necessary, it "must be capable of producing a change in position substantially greater than the predicted position uncertainties at the time of the hazardous encounter [otherwise it] would instead create an unpredicted outcome or a new hazard." See JPL's summary and more about the above image, which is credited to Lance Benner.

Contents  on 15 November '07


Editor's note: On November 14th we launched an additional semi-automated news page, the Traffic Report for Earth's Busy Neighborhood. (It is "automated" in that, like with this page and the CRT, all the data is collected and published by program scripts without human intervention, but, to be exact, it is "semi-automated" since these activities don't yet run unattended.)

The latest news: framed access (best), RSS news feed RSS news feed (flags updates), or redirection - Note: A/CC has a main Web site and a backup site, which now has its own backup RSS news feed.

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 this year 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 15 November '07

The MPC's NEO Confirmation Page has 22 listings: 8 new, 14 updated

When last checked at 2354 UTC today, the Minor Planet Center's NEO discovery Confirmation Page (NEOCP) had eight new and fourteen updated listings. Of these, fifteen were "one nighters." So far The Tracking News has counted a total of 31 objects listed on the NEOCP at some point today.

To learn how observers use the NEOCP, see the Practical guide on how to observe NEOCP object by Birtwhistle et al. at Suno Observatory.

New MPECs  on 15 November '07

Minor Planet Electronic Circulars

As of last check at 2354 UTC, there have been six MPECs issued today from the International Astronomical Union's Minor Planet Center in Cambridge, Massachusetts.

MPEC 2007-V119 - "14:05 UT" - 2007 VF189

MPEC 2007-V118 - "14:00 UT" - 2007 VJ189

MPEC 2007-V117 - "13:57 UT" - 2007 VH189

MPEC 2007-V116 - "13:54 UT" - 2007 VG189

MPEC 2007-V115 - "13:42 UT" - 2007 VE189

<< DOU on 15 Nov. '07 >>  MPEC 2007-V114 - "07:13 UT" - Daily Orbit Update

Observers  on 15 November '07

Sixteen observing facilities appear in today's MPECs.

CodeObserver / observatory
H55Astronomical Research Obs. in Illinois, 1 in MPEC 2007-V114 -- 2002 XY4
J51Atlante Obs. in the Canary Islands, 2 in MPEC 2007-V114 -- 162004, 3553
432Boambee Obs. in New South Wales, 1 in MPEC 2007-V114 -- 66959
703Catalina Sky Survey (CSS) in Arizona, 11 in MPECs 2007-V114 & 2007-V119 -- 2007 VF189, 2007 VD138, 2007 RA9, 2007 LV, 87684, 21277, 144900, 138883, 138013, 11405, 5587
808El Leoncito Obs. in Argentina, 5 in MPEC 2007-V114 -- 2007 DL8, 2005 SA71, 85275, 66959, 138883
J95Great Shefford Obs. in England, 3 in MPECs 2007-V116, 2007-V117 & 2007-V118 -- 2007 VJ189, 2007 VH189, 2007 VG189
379Hamamatsu-Yuto Obs. in Japan, 3 in MPEC 2007-V114 -- 2007 VD12, 2007 SE11, 2007 PU11
704LINEAR in New Mexico, 10 in MPEC 2007-V114 -- 2007 VA188, 2007 UQ51, 2007 SP6, 2007 RU12, 2005 TF49, 2002 UA31, 152558, 145656, 11500, 4486
699LONEOS in Arizona, 3 in MPEC 2007-V114 -- 68063, 163902, 138852
G96Mt. Lemmon Survey (MLS) in Arizona, 9 in MPECs 2007-V114, 2007-V115, 2007-V117, 2007-V118 & 2007-V119 -- 2007 VV6, 2007 VJ189, 2007 VH189, 2007 VF189, 2007 VE189, 2007 VD3, 2007 UW3, 1998 XX2, 1994 AW1
J93Mt. Tuffley Obs. in England, 1 in MPEC 2007-V114 -- 4954
H45Petit Jean Mtn. South Obs. (PJMSO) in Arkansas, 6 in MPEC 2007-V114 -- 2007 US6, 2007 TB23, 2007 SE11, 2007 RU12, 2007 RP133, 2007 PU11
D21Shenton Park Obs. in Western Australia, 6 in MPECs 2007-V114 & 2007-V119 -- 2007 VM184, 2007 VK184, 2007 VJ184, 2007 VG184, 2007 VF189, 2007 VD138
E12Siding Spring Survey (SSS) in New South Wales, 2 in MPEC 2007-V114 -- 2004 XP164, 159608
691Spacewatch 0.9m telescope in Arizona, 9 in MPECs 2007-V114 & 2007-V116 -- 2007 VG189, 2007 VE3, 2007 TV68, 2005 YW55, 2005 XL80, 19764, 143651, 8034, 4503
291Spacewatch 1.8m telescope in Arizona, 5 in MPECs 2007-V114 & 2007-V116 -- 2007 VT6, 2007 VG189, 2007 VG, 2007 UR51, 2007 PU11

Impact Risk Monitoring  on 15 November '07

Summary Risk Table for Risk Assessments Updated Today   (last checks: NEODyS and JPL at 2354 UTC)
See the CRT page for a list of all objects rated recently as risks.
Note that the time horizon for JPL is 100 years from today and for NEODyS is now usually the year 2090.
For the latest official risk assessments, and for explanations of the terminology, see the JPL NEO Program Sentry and NEODyS CLOMON (backup) risk pages.





Notes for Today's Latest Risk Assessments
2007 VH189JPL Sentry18592010-21073129.2e-07-4.79-5.870JPL: "Analysis based on 17 observations spanning .90314 days (2007-Nov-14.35096 to 2007-Nov-15.2541)." Diameter approximately 0.071 km. from mean, weighted H=23.4.
2007 VK184NEODyS20322037-2090351.08e-04-2.39-2.900NEODyS: "Based on 37 optical observations (of which 0 are rejected as outliers) from 2007/11/12.140 to 2007/11/14.528."
JPL Sentry13522035-2075351.1e-04-2.39-2.870JPL: "Analysis based on 37 observations spanning 2.3886 days (2007-Nov-12.13904 to 2007-Nov-14.5276)." Diameter approximately 0.140 km. from mean, weighted H=22.0.

Legend: VI# = VI count, Prob Cum = cumulative probability, PS Cum/Max = cumulative/maximum Palermo Scale, TS = Torino Scale

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 15 November '07

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

2032Noted that NEODyS has updated its 2007 VK184 risk assessment - see above
1859Noted that JPL Sentry has posted 2007 VH189 as an impact risk - see above
1526Grabbed MPEC 2007-V119 - 2007 VF189 - see above
1432Grabbed MPEC 2007-V116 - 2007 VG189 - see above
Grabbed MPEC 2007-V117 - 2007 VH189 - see above
Grabbed MPEC 2007-V118 - 2007 VJ189 - see above
1353Grabbed MPEC 2007-V114 - Daily Orbit Update - see above
1352Noted that JPL Sentry has updated its 2007 VK184 risk assessment - see above
Grabbed MPEC 2007-V115 - 2007 VE189 - see above