Contents  on 28 February '15

Asteroid/Comet Connection (A/CC) Resources:

The latest A/CC news is available via framed access, RSS news feed RSS news feed, or redirection.

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. To keep track of what's new each day, watch the Chronology section.

Traffic Report  on 28 February '15

Four objects reported inside ten LD

Four asteroids are reported to be within ten lunar distances (LD) of Earth today. 2015 DY198 is inbound from 5.79 to 2.77 LD and 2015 DS53 from 9.68 to 6.72 LD, while NHATS target 2015 DU is outbound from 8.20 to 8.31 LD and NHATS target 2015 CA40 leaves ten LD, moving from 9.73 to 11.17 LD.

Next known to be on approach, 2015 DK200 comes inside ten LD on March 4th.

This report was generated at 1533 UTC with follow-up in today's DOU MPEC for 2015 DS53, 2015 DU, and departed risk-listed 2015 DD54, plus astrometry for distant objects 425755 2011 CP4, 406213 2007 AB2, and 136617 1994 CC.

Notes: Ten times the distance to the Moon (ten LD) has no astronomical importance but puts a focus on transient natural objects that have recently approached the actually significant gravitational sphere of influence (SOI), which has a radius of about 2.41 LD from Earth's center, and thus also puts a focus on some of the most important and very best NEO observation work. "Distant" is used here to describe objects that have come within ten LD since this reporting began but are not so close during their reported apparitions. 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 28 February '15

The MPC's NEO Confirmation Page has 86 listings

When last checked at 2359 UTC today, the Minor Planet Center's Near Earth Object discovery Confirmation Page (NEOCP) had 86 objects listed. Of these, 49 were "one nighters." So far The Tracking News has counted a total of 88 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 28 February '15

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 2015-D114 - "14:05 UT" - 2015 DJ215

<< DOU on 28 Feb. '15 >>  MPEC 2015-D113 - "12:05 UT" - Daily Orbit Update

Observers  on 28 February '15

Fifteen observers appear in today's MPECs.

CodeObserver / observatory
H21Astronomical Research Obs. Westfield in Illinois, 4 in MPEC 2015-D113 -- 2002 CZ58, 137924, 3691, 1627
160Castelmartini Obs. in Italy, 5 in MPEC 2015-D113 -- 2015 BW92, 419829, 417264, 311554, 159454
703Catalina Sky Survey (CSS) in Arizona, 17 in MPEC 2015-D113 -- 2015 DU, 2015 DT, 2015 CN13, 2015 CA1, 2015 BZ310, 2008 ES, 2000 VH61, 1998 GL10, 423709, 419880, 413820, 322763, 306462, 232368, 12923, 3271, 1864
807|Robert Holmes in Illinois via Cerro Tololo Inter-American Obs. (CTIO) in Chile, 14 in MPEC 2015-D113 -- 2014 YG14, 2014 VU6, 2010 CH55, 1999 RJ27, 425755, 406213, 38086, 378160, 310560, 27346, 177016, 174050, 155110, 141484
5682David Tholen's team on Mauna Kea in Hawaii, 3 in MPECs 2015-D113 & 2015-D114 -- 2015 DJ215, 2015 DF198, 2015 DA200
568_Marco Micheli on Mauna Kea in Hawaii, 1 in MPEC 2015-D114 -- 2015 DJ215
G96Mt. Lemmon Survey (MLS) in Arizona, 4 in MPEC 2015-D113 -- 2015 CU, 2014 NE52, 2006 SV189, 2004 BV1
J43Oukaimeden Obs. in Morocco, 1 in MPEC 2015-D113 -- 425450
C27Pallerols Obs. in Spain, 1 in MPEC 2015-D113 -- 90367
F51Pan-STARRS 1 (PS1) in Hawaii, 18 in MPECs 2015-D113 & 2015-D114 -- 2015 DU198, 2015 DU180, 2015 DJ215, 2015 BP510, 2009 NJ, 2008 GX, 2006 WW, 2006 HV57, 1995 FO, 85236, 425713, 413820, 348400, 24445, 159504, 136617, 6053, 5370
W95Panamanian San Pedro Atacama Obs. in Chile, 1 in MPEC 2015-D113 -- 4055
L04ROASTERR-1 Obs. in Romania, 1 in MPEC 2015-D113 -- 2015 DP53
W882Don Cranford, Jr. in North Carolina via Chile Obs. in Chile, 1 in MPEC 2015-D113 -- 2015 DS53
691Spacewatch 0.9m telescope in Arizona, 1 in MPEC 2015-D113 -- 2015 DO155
291Spacewatch 1.8m telescope in Arizona, 2 in MPEC 2015-D113 -- 2015 DR, 2015 DD54
C51WISE in Earth polar orbit, 2 in MPEC 2015-D113 -- 2011 OL5, 413123
For a list of all participating observatories that have Web addresses, see A/CC's Observatory Links page.

Impact Risk Monitoring  on 28 February '15

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
2015 DF198NEODyS1703R E M O V E D-
2015 DU180NEODyS1703211013.82e-09-6.06-6.060NEODyS: "Based on 28 optical observations (of which 1 are rejected as outliers) from 2015-02-20.573 to 2015-02-25.500."
JPL Sentry15252068-210751.9e-08-5.33-5.430JPL: "Analysis based on 27 observations spanning 4.9269 days (2015-Feb-20.57213 to 2015-Feb-25.499046)." Diameter approximately 0.240 km. from mean, weighted H=20.7.
2015 DD54NEODyS17032112-211433.78e-06-6.06-6.06n/aNEODyS: "Based on 82 optical observations (of which 0 are rejected as outliers) from 2015-01-20.326 to 2015-02-27.512."
JPL Sentry1525211414.1e-06-6.02-6.020JPL: "Analysis based on 82 observations spanning 38.186 days (2015-Jan-20.32497 to 2015-Feb-27.51119)." Diameter approximately 0.028 km. from mean, weighted H=25.4.
2015 DA54NEODyS1703R E M O V E D-

Legend: VI# = VI count, Prob Cum = cumulative probability, PS Cum/Max = cumulative/maximum Palermo Scale, TS = Torino Scale (next 100 years)

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 28 February '15

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

1703Noted that NEODyS has removed 2015 DA54 as an impact risk - see above
Noted that NEODyS has updated its 2015 DD54 risk assessment - see above
Noted that NEODyS has removed 2015 DF198 as an impact risk - see above
Noted that NEODyS has updated its 2015 DU180 risk assessment - see above
1533Generated Traffic Report
1525Noted that JPL Sentry has updated its 2015 DD54 risk assessment - see above
Noted that JPL Sentry has updated its 2015 DU180 risk assessment - see above
Grabbed MPEC 2015-D113 - Daily Orbit Update - see above
Grabbed MPEC 2015-D114 - 2015 DJ215 - see above