Contents  on 24 December '12

Asteroid/Comet Connection (A/CC) Resources:

The latest A/CC news is available via framed access, RSS news feed RSS news feed, or redirection. - Note: A/CC has a main Web site and also a backup site with its own duplicate 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 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.

Traffic Report  on 24 December '12

Three objects reported inside ten LD

There are three objects reported inside ten lunar distances (LD) of our planet today. Within Earth's Hill sphere, radar target 2012 XM55 is outbound from 3.05 to 3.13 LD. Further out, 2012 YS1 comes its closest to Earth on this passage, reaching 8.15 LD at 1142 UT, and radar target intruder 2012 XB112 is outbound from 8.94 to 9.90 LD.

Headed our way next, 2012 XP55 arrives inside ten LD on December 26th.

This report was generated at 1604 UTC with follow-up in today's DOU MPEC for 2012 XP55.

Notes: Ten times the distance to the Moon (ten LD) has no astronomical significance but is a useful reporting boundary. Earth's Hill sphere (of gravitational influence) is estimated to extend out to around 3.89 LD. Object distances are interpreted 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 24 December '12

The MPC's NEO Confirmation Page has 55 listings

When last checked at 2359 UTC today, the Minor Planet Center's Near Earth Object discovery Confirmation Page (NEOCP) had 55 objects listed. Of these, 39 were "one nighters." So far The Tracking News has counted a total of 61 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 24 December '12

Minor Planet Electronic Circulars

As of last check at 2359 UTC, there has been one MPEC posted today from the International Astronomical Union's Minor Planet Center in Cambridge, Massachusetts.

<< DOU on 24 Dec. '12 >>  MPEC 2012-Y27 - "06:05 UT" - Daily Orbit Update

Observers  on 24 December '12

Ten observers appear in today's MPEC.

CodeObserver / observatory
H21Astronomical Research Obs. Westfield in Illinois, 11 in MPEC 2012-Y27 -- 2012 YO1, 2012 YK, 2012 XY6, 2012 XT134, 2012 XP55, 2012 XP111, 2012 XM134, 2012 XC112, 2012 VK77, 333358, 3838
300Bisei Spaceguard Center in Japan, 3 in MPEC 2012-Y27 -- 2012 QF49, 2001 YM2, 4179
G32Elena Remote Obs., 1 in MPEC 2012-Y27 -- 2012 YQ1
F658David Tholen's team in Hawaii via Faulkes Telescope North in Hawaii, 2 in MPEC 2012-Y27 -- 2012 XC112, 2012 WQ10
844Los Molinos Obs. in Uruguay, 5 in MPEC 2012-Y27 -- 88213, 331509, 189173, 163732, 138937
5682David Tholen's team on Mauna Kea in Hawaii, 1 in MPEC 2012-Y27 -- 2012 VP6
F51Pan-STARRS 1 (PS1) in Hawaii, 14 in MPEC 2012-Y27 -- 2012 XS93, 2009 BD2, 2007 BM8, 68063, 337075, 26166, 222165, 177614, 164216, 162825, 159533, 141354, 112985, 1685
H23Pear Tree Obs. in Florida, 2 in MPEC 2012-Y27 -- 2012 XC112, 2012 VF37
D03Rantiga Obs., 1 in MPEC 2012-Y27 -- 2001 YM2
H47Vicksburg Obs. in Mississippi, 2 in MPEC 2012-Y27 -- 7350, 5646
For a list of all participating observatories that have Web addresses, see A/CC's Observatory Links page.

Impact Risk Monitoring  on 24 December '12

Summary Risk Table for Risk Assessments Updated Today   (last checks: NEODyS and JPL at 2359 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 JPL NEO Program Sentry and NEODyS CLOMON2 risk pages.





Notes for Today's Latest Risk Assessments
2012 YQ1JPL Sentry1600210613.3e-07-4.78-4.780JPL: "Analysis based on 34 observations spanning 4.0260 days (2012-Dec-19.23613 to 2012-Dec-23.26216)." Diameter approximately 0.220 km. from mean, weighted H=20.9.

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 24 December '12

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

1604Generated Traffic Report
1600Noted that JPL Sentry has updated its 2012 YQ1 risk assessment - see above
Grabbed MPEC 2012-Y27 - Daily Orbit Update - see above