An astronaut exploring a small asteroid. 
Illustration credit: NASA/JPL NEOPO.

The NASA/JPL NEO Program Office yesterday announced its new Near-Earth Object Human Space Flight Accessible Targets Study (NHATS) Web site. See the intro, default table, and complete list in ascending object designation order. Illustration of an astronaut exploring a small asteroid, credit NASA/JPL NEOPO.

Contents  on 21 March '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 21 March '12

Five objects reported inside ten LD

Five asteroids are reported traveling within ten lunar distances (LD) of Earth today. Inside Earth's Hill sphere, 2012 EO8 comes its closest to Earth on this passage, reaching 3.60 LD at 1711 UTC. Further away, risk-listed 2012 EK5 comes in from 7.14 to 5.86 LD, while 2012 EL8 is outbound from 8.0 to 8.3 LD* and 2012 EJ5 from 9.17 to 9.94 LD, and 2012 FM departs from inside ten LD, passing from 9.39 to 10.21 LD.

Coming toward Earth, radar target intruder 2012 EG5 arrives inside ten LD on March 27th and 2007 HV4 comes inside on April 14th.

This report was posted at 1629 UTC with follow-up in today's DOU MPEC for 2012 EO8 and 2012 EG5.

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. "LD*" indicates some passage uncertainty. See also current sky chart and object details (alt-details), ephemerides, and today's timeline.

NEOCP Activity  on 21 March '12

The MPC's NEO Confirmation Page has 15 listings

When last checked at 2359 UTC today, the Minor Planet Center's Near Earth Object discovery Confirmation Page (NEOCP) had fifteen objects listed. Of these, thirteen were "one nighters." So far The Tracking News has counted a total of seventeen 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 21 March '12

Minor Planet Electronic Circulars

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

<< DOU on 21 Mar. '12 >>  MPEC 2012-F47 - "06:03 UT" - Daily Orbit Update

MPEC 2012-F46 - "03:52 UT" - 2007 DS84

MPEC 2012-F45 - "03:37 UT" - 2011 HS4

Observers  on 21 March '12

Nineteen observers appear in today's MPECs.

CodeObserver / observatory
300Bisei Spaceguard Center in Japan, 3 in MPEC 2012-F47 -- 2012 EO8, 2012 EK8, 2012 EG5
160Castelmartini Obs. in Italy, 6 in MPEC 2012-F47 -- 2012 DH4, 317643, 312942, 267221, 263976, 141018
807|Robert Holmes in Illinois via Cerro Tololo Inter-American Obs. (CTIO) in Chile, 2 in MPEC 2012-F47 -- 2012 FR1, 2012 ES14
G48Doc Greiner Research Obs. Rancho Hildalgo (DGRO-RH) in New Mexico, 3 in MPEC 2012-F47 -- 2012 EK8, 2012 CA55, 136618
113Drebach Obs. in Germany, 1 in MPEC 2012-F47 -- 2012 CA55
639Dresden Obs. in Germany, 2 in MPEC 2012-F47 -- 2012 EO8, 2012 EK8
151Eschenberg Obs. in Switzerland, 3 in MPEC 2012-F47 -- 2012 EK8, 2012 CA55, 1998 KN3
F659Marco Micheli in Hawaii via Faulkes Telescope North in Hawaii, 1 in MPEC 2012-F47 -- 2012 FQ1
C73Galati Obs. in Romania, 9 in MPEC 2012-F47 -- 2012 CA55, 2004 QJ7, 275558, 267221, 21277, 162186, 155336, 9400, 4055
A17Guidestar Obs. in Germany, 3 in MPEC 2012-F47 -- 2012 DX75, 2012 DO8, 2012 DK61
246KLENOT in the Czech Republic, 1 in MPEC 2012-F47 -- 2012 EG5
046Klet Obs. in the Czech Republic, 1 in MPEC 2012-F47 -- 2012 EK8
C41MASTER-II Obs. Kislovodsk in Russia, 1 in MPEC 2012-F47 -- 66251
5682David Tholen's team on Mauna Kea in Hawaii, 1 in MPEC 2012-F47 -- 2012 EC
5683Christian Veillet on Mauna Kea in Hawaii, 2 in MPECs 2012-F45 & 2012-F46 -- 2011 HS4, 2007 DS84
A24New Millennium Obs. in Italy, 23 in MPEC 2012-F47 -- 2012 DX75, 2012 DH4, 2012 BC20, 2011 YV15, 2011 SL102, 68267, 36183, 317643, 306595, 302830, 275558, 263976, 238063, 21277, 184990, 171819, 163000, 162038, 154555, 9400, 6455, 5620, 3352
F51Pan-STARRS 1 (PS1) in Hawaii, 11 in MPEC 2012-F47 -- 2012 EU14, 2012 DG61, 2012 BK77, 2012 AN23, 2008 YU32, 2001 HA8, 1998 FF14, 53319, 306595, 153814, 152667
D90`Kevin Hills in England via RAS Obs. Moorook in South Australia, 1 in MPEC 2012-F47 -- 2012 EG5
B04Saint-Barthelemy Obs. in Italy, 1 in MPEC 2012-F47 -- 99942
I15Wishing Star Obs. in Rhode Island, 4 in MPEC 2012-F47 -- 2012 CC17, 2012 CA55, 312942, 20826
For a list of all participating observatories that have Web addresses, see A/CC's Observatory Links page.

Impact Risk Monitoring  on 21 March '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 FR1JPL Sentry16262024-2073136.5e-08-3.48-3.580JPL: "Analysis based on 25 observations spanning 4.0096 days (2012-Mar-16.40434 to 2012-Mar-20.41398)." Diameter approximately 0.575 km. from mean, weighted H=18.8.
NEODyS16262024-2070111.03e-08-4.30-4.520NEODyS: "Based on 25 optical observations (of which 0 are rejected as outliers) from 2012-03-16.405 to 2012-03-20.415."
2012 FQ1JPL Sentry16262021-2108395.3e-07-3.18-3.580JPL: "Analysis based on 20 observations spanning 3.1323 days (2012-Mar-16.16837 to 2012-Mar-19.300689)." Diameter approximately 0.522 km. from mean, weighted H=19.1.
NEODyS16262021-2071132.03e-07-3.54-3.860NEODyS: "Based on 20 optical observations (of which 0 are rejected as outliers) from 2012-03-16.169 to 2012-03-19.301."
2012 ECJPL Sentry16262083-210748.9e-06-4.79-4.930JPL: "Analysis based on 74 observations spanning 17.210 days (2012-Mar-01.3419 to 2012-Mar-18.551899)." Diameter approximately 0.066 km. from mean, weighted H=23.5.
NEODyS16262049-209044.53e-07-5.98-6.20NEODyS: "Based on 74 optical observations (of which 0 are rejected as outliers) from 2012-03-01.343 to 2012-03-18.553."

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 21 March '12

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

1629Posted Traffic Report
1626Noted that JPL Sentry has updated its 2012 EC risk assessment - see above
Noted that NEODyS has updated its 2012 EC risk assessment - see above
Noted that JPL Sentry has updated its 2012 FQ1 risk assessment - see above
Noted that NEODyS has updated its 2012 FQ1 risk assessment - see above
Noted that JPL Sentry has updated its 2012 FR1 risk assessment - see above
Noted that NEODyS has updated its 2012 FR1 risk assessment - see above
Grabbed MPEC 2012-F47 - Daily Orbit Update - see above
0616Grabbed MPEC 2012-F45 - 2011 HS4 - see above
Grabbed MPEC 2012-F46 - 2007 DS84 - see above