Contents  on 27 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 27 December '12

Two objects reported inside ten LD

Two visitors are reported flying within ten lunar distances (LD) of our planet today. Radar target 2012 XM55 exits Earth's Hill sphere, traveling from 3.64 to 4.01 LD, and 2012 XP55 comes its closest to Earth on this passage, reaching 9.17 LD at 0945 UT.

No other object is known to come this close until intruder 2012 DA14, a risk-listed radar target, arrives inside ten LD on February 8th.

This report was generated at 1611 UTC.

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 27 December '12

The MPC's NEO Confirmation Page has 22 listings

When last checked at 2359 UTC today, the Minor Planet Center's Near Earth Object discovery Confirmation Page (NEOCP) had 22 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 27 December '12

Minor Planet Electronic Circulars

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

MPEC 2012-Y33 - "20:35 UT" - 2004 UU1

<< DOU on 27 Dec. '12 >>  MPEC 2012-Y32 - "06:03 UT" - Daily Orbit Update

Observers  on 27 December '12

Five observers appear in today's MPECs.

CodeObserver / observatory
807|Robert Holmes in Illinois via Cerro Tololo Inter-American Obs. in Chile, 1 in MPEC 2012-Y32 -- 2012 YQ1
F658David Tholen's team in Hawaii via Faulkes Telescope North in Hawaii, 1 in MPEC 2012-Y32 -- 2012 XS111
950\program code "\" (26) via La Palma in the Canary Islands, 1 in MPEC 2012-Y32 -- 136793
5682David Tholen's team on Mauna Kea in Hawaii, 1 in MPEC 2012-Y33 -- 2004 UU1
A24New Millennium Obs. in Italy, 28 in MPEC 2012-Y32 -- 2012 VF37, 2012 TA79, 2012 TA219, 2012 SA59, 2012 HJ1, 2008 XE2, 2001 YM2, 2000 WL63, 1994 XD, 68548, 330825, 329338, 277127, 256412, 222165, 189173, 17188, 17182, 159533, 153958, 152742, 144411, 141052, 137052, 5646, 3360, 3200, 2212
For a list of all participating observatories that have Web addresses, see A/CC's Observatory Links page.

Impact Risk Monitoring  on 27 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 Sentry16072106-210924.1e-07-4.68-4.760JPL: "Analysis based on 39 observations spanning 6.0444 days (2012-Dec-19.23613 to 2012-Dec-25.28052)." Diameter approximately 0.230 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 27 December '12

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

2104Grabbed MPEC 2012-Y33 - 2004 UU1 - see above
1611Generated Traffic Report
1607Noted that JPL Sentry has updated its 2012 YQ1 risk assessment - see above
Grabbed MPEC 2012-Y32 - Daily Orbit Update - see above