Contents  on 11 April '13

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 11 April '13

Three objects reported inside ten LD

There are three asteroids reported to be within ten lunar distances (LD) of our planet today. Risk-listed 2010 GM23 may be inbound from 9.6 to 7.0 LD*, newly announced risk-listed 2013 GW38 departs from inside ten LD, traveling from 7.68 to 10.01 LD, and new discovery 2013 GB55 enters ten LD, passing from 10.38 to 9.93 LD.

Approaching our neighborhood next, 2013 GH23 arrives inside ten LD on April 16th.

This report was updated at 2151 UTC with new discoveries 2013 GB55 (MPEC) and departees 2013 GD55 (MPEC) and risk-listed 2013 GA55 (MPEC). Today's first traffic report was generated at 0452 UTC with the discovery announced late yesterday of 2013 GW38 (MPEC).

Notes: Ten times the distance to the Moon (ten LD) has no astronomical significance but is a useful reporting boundary. 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 11 April '13

The MPC's NEO Confirmation Page has 42 listings

When last checked at 2359 UTC today, the Minor Planet Center's Near Earth Object discovery Confirmation Page (NEOCP) had 42 objects listed. Of these, 23 were "one nighters." So far The Tracking News has counted a total of 52 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 11 April '13

Minor Planet Electronic Circulars

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

MPEC 2013-G53 - "23:58 UT" - 2012 XS93

MPEC 2013-G52 - "18:17 UT" - 2013 GE55

MPEC 2013-G51 - "18:13 UT" - 2013 GD55

MPEC 2013-G50 - "18:10 UT" - 2013 GC55

MPEC 2013-G49 - "18:07 UT" - 2013 GB55

MPEC 2013-G48 - "18:03 UT" - 2013 GA55

MPEC 2013-G47 - "17:59 UT" - 2013 GY54

<< DOU on 11 Apr. '13 >>  MPEC 2013-G46 - "06:03 UT" - Daily Orbit Update

Observers  on 11 April '13

A total of 23 observers appear in today's MPECs.

CodeObserver / observatory
E23Arcadia Obs. in New South Wales, 1 in MPEC 2013-G51 -- 2013 GD55
300Bisei Spaceguard Center in Japan, 1 in MPEC 2013-G51 -- 2013 GD55
703Catalina Sky Survey (CSS) in Arizona, 4 in MPECs 2013-G46, 2013-G49 & 2013-G50 -- 2013 GC55, 2013 GB55, 356285, 152952
807|Robert Holmes in Illinois via Cerro Tololo Inter-American Obs. (CTIO) in Chile, 14 in MPECs 2013-G46, 2013-G48, 2013-G50 & 2013-G51 -- 2013 GJ, 2013 GD55, 2013 GC55, 2013 GA55, 2013 FD11, 2013 FC8, 2013 EN126, 2013 CL89, 2013 BD70, 2012 VO6, 2005 EJ94, 2002 TR190, 1991 FB, 152756
J04ESA Optical Ground Station (ESA OGS) in the Canary Islands, 4 in MPECs 2013-G46 & 2013-G50 -- 2013 GR38, 2013 GO3, 2013 GG, 2013 GC55
695{Tomas Vorobjov in England via Kitt Peak Natl. Obs. in Arizona, 1 in MPEC 2013-G47 -- 2013 GY54
W85LCOGT Cerro Tololo A in Chile, 2 in MPECs 2013-G48 & 2013-G52 -- 2013 GE55, 2013 GA55
W87LCOGT Cerro Tololo C in Chile, 1 in MPEC 2013-G47 -- 2013 GY54
809:program code ":" via La Silla in Chile, 1 in MPEC 2013-G46 -- 2007 WW4
5682David Tholen's team on Mauna Kea in Hawaii, 2 in MPECs 2013-G46 & 2013-G48 -- 2013 GM3, 2013 GA55
568_Marco Micheli on Mauna Kea in Hawaii, 1 in MPEC 2013-G46 -- 2010 LF14
G96Mt. Lemmon Survey (MLS) in Arizona, 6 in MPECs 2013-G46, 2013-G47, 2013-G49, 2013-G51 & 2013-G52 -- 2013 GY54, 2013 GE55, 2013 GD55, 2013 GB55, 2013 EK89, 7480
644NEAT's Mt. Palomar telescope in southern California, 1 in MPEC 2013-G53 -- 2012 XS93
J43Oukaimeden Obs. in Morocco, 1 in MPEC 2013-G46 -- 2013 FA8
F51Pan-STARRS 1 (PS1) in Hawaii, 16 in MPECs 2013-G46, 2013-G47 & 2013-G48 -- 2013 GY54, 2013 GN3, 2013 GA55, 2013 FY13, 2013 FC11, 2008 HB38, 2007 HF44, 65909, 354952, 274855, 164201, 161998, 6050, 2059, 1917, 719
D90`Kevin Hills in England via RAS Obs. Moorook in South Australia, 1 in MPEC 2013-G51 -- 2013 GD55
461SZTE Asteroid Program in Hungary, 1 in MPEC 2013-G51 -- 2013 GD55
204Schiaparelli Obs. in Italy, 2 in MPECs 2013-G47 & 2013-G50 -- 2013 GY54, 2013 GC55
E12Siding Spring Survey (SSS) in New South Wales, 2 in MPEC 2013-G46 -- 2013 GJ35, 2013 GJ
G401program code 1 via Canary Islands Obs. in the Canary Islands, 2 in MPEC 2013-G46 -- 2013 FY13, 7888
291Spacewatch 1.8m telescope in Arizona, 9 in MPECs 2013-G46, 2013-G48 & 2013-G52 -- 2013 GM3, 2013 GL8, 2013 GE55, 2013 GA55, 2013 FW13, 2013 FQ10, 2013 FA8, 2013 BJ18, 2011 BH10
D06Tuscolana Assoc. Obs., 1 in MPEC 2013-G46 -- 7888
G56Walnut Creek Obs. in northern California, 1 in MPEC 2013-G46 -- 2013 EV108
H06|Hidetaka Sato in Japan via iTelescope Obs. Mayhill in New Mexico, 1 in MPEC 2013-G47 -- 2013 GY54
For a list of all participating observatories that have Web addresses, see A/CC's Observatory Links page.

Impact Risk Monitoring  on 11 April '13

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
2013 GE55JPL Sentry20502024-207267.5e-10-7.95-8.420JPL: "Analysis based on 13 observations spanning .99858 days (2013-Apr-10.47552 to 2013-Apr-11.4741)." Diameter approximately 0.084 km. from mean, weighted H=23.0.
2013 GA55JPL Sentry20502064-2111301.2e-05-6.50-7.330JPL: "Analysis based on 14 observations spanning 1.7271 days (2013-Apr-09.44557 to 2013-Apr-11.17271)." Diameter approximately 0.010 km. from mean, weighted H=27.7.
2013 GW38NEODyS13492061-2109131.28e-05-6.65-6.760NEODyS: "Based on 18 optical observations (of which 0 are rejected as outliers) from 2013-04-09.453 to 2013-04-10.794."
JPL Sentry00562061-2109138.6e-06-6.88-7.110JPL: "Analysis based on 18 observations spanning 1.3411 days (2013-Apr-09.45225 to 2013-Apr-10.79339)." Diameter approximately 0.007 km. from mean, weighted H=28.5.
2013 GS38JPL Sentry04342017-2110221.2e-08-5.39-5.520JPL: "Analysis based on 9 observations spanning 3.9738 days (2013-Apr-06.31837 to 2013-Apr-10.29216)." Diameter approximately 0.277 km. from mean, weighted H=20.4.
2013 GJ35JPL Sentry16052015-2104344.0e-08-1.92-1.980JPL: "Analysis based on 32 observations spanning 4.0659 days (2013-Apr-06.7433 to 2013-Apr-10.80916)." Diameter approximately 2.200 km. from mean, weighted H=15.9.
NEODyS13492015-2112383.86e-08-1.61-1.650NEODyS: "Based on 32 optical observations (of which 0 are rejected as outliers) from 2013-04-06.744 to 2013-04-10.810."
2013 GL8JPL Sentry1349208411.2e-09-5.54-5.540JPL: "Analysis based on 18 observations spanning 7.8851 days (2013-Apr-03.24377 to 2013-Apr-11.12889)." Diameter approximately 0.650 km. from mean, weighted H=18.6.
2013 GM3JPL Sentry13492028-21121981.5e-04-4.61-5.380JPL: "Analysis based on 45 observations spanning 7.8657 days (2013-Apr-03.32112 to 2013-Apr-11.18683)." Diameter approximately 0.019 km. from mean, weighted H=26.2.
NEODyS13492028-20901046.63e-05-4.93-5.770NEODyS: "Based on 45 optical observations (of which 2 are rejected as outliers) from 2013-04-03.322 to 2013-04-11.188."
2013 FC11NEODyS1349R E M O V E D-

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 11 April '13

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

2359Grabbed MPEC 2013-G53 - 2012 XS93 - see above
2151Updated Traffic Report
2050Noted that JPL Sentry has posted 2013 GA55 as an impact risk - see above
Noted that JPL Sentry has posted 2013 GE55 as an impact risk - see above
1839Grabbed MPEC 2013-G47 - 2013 GY54 - see above
Grabbed MPEC 2013-G48 - 2013 GA55 - see above
Grabbed MPEC 2013-G49 - 2013 GB55 - see above
Grabbed MPEC 2013-G50 - 2013 GC55 - see above
Grabbed MPEC 2013-G51 - 2013 GD55 - see above
Grabbed MPEC 2013-G52 - 2013 GE55 - see above
1605Noted that JPL Sentry has updated its 2013 GJ35 risk assessment - see above
1349Noted that NEODyS has removed 2013 FC11 as an impact risk - see above
Noted that NEODyS has updated its 2013 GJ35 risk assessment - see above
Noted that JPL Sentry has updated its 2013 GL8 risk assessment - see above
Noted that JPL Sentry has updated its 2013 GM3 risk assessment - see above
Noted that NEODyS has updated its 2013 GM3 risk assessment - see above
Noted that NEODyS has posted 2013 GW38 as an impact risk - see above
Grabbed MPEC 2013-G46 - Daily Orbit Update - see above
0434Noted that JPL Sentry has posted 2013 GS38 as an impact risk - see above
0056Noted that JPL Sentry has posted 2013 GW38 as an impact risk - see above