Contents  on 21 February '17

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 21 February '17

Five objects reported inside ten LD

Five asteroids are known to be inside ten lunar distances (LD) of Earth today. Nearest is NHATS target 2017 DB, moving away from 1.91 to 2.99 LD, leaving the planet's SOI and coming its closest to the Moon on this passage -- 2.74 LD at 0107 UTC. Much further out, risk-listed radar target 2017 BY93 enters the ten LD space, zooming in from 12.83 to 8.62 LD.

Earth passage I D ~Size Distance Today  Notes
1.82 LD yesterday2017 DB 13 m  1.91 to 2.99 LD exits Earth SOI, NHATS target, Moon closest 2.74 LD at 0107 UTC
2.09 LD Feb. 192017 DF 16 m  2.84 to 3.75 LD NHATS target
2.37 LD Feb. 232017 BY93 82 m  8.62 from 12.83 LD enters ten LD, radar target, risk - DOU
3.58 LD Feb. 242017 CP1 40 m  4.36 from 5.02 LD radar/NHATS target - DOU
4.63 LD Feb. 172017 BW 69 m  6.35 to 7.15 LD radar/NHATS target

This report was generated at 1748 UTC with follow-up in today's DOU MPEC for inbound 2017 BY93 and radar/NHATS target 2017 CP1, approaching 2017 CS, and departed objects 2017 CP32, radar/NHATS target 2017 CF32, and NHATS target 2017 AG5.

Approaching (sorted by 10-LD bubble entry date)
2.7   LD March 22012 DR32 41 m  < 10 LD Feb. 28, uncertainty +/- 4.1333 hours
8.34 LD March 161998 SL36 309 m  < 10 LD March 14, radar target
7.63 LD March 262015 TC25 4 m  < 10 LD March 17, radar/NHATS target, risk
4.57 LD April 192014 JO25 812 m  < 10 LD April 18, radar target
7.9   LD May 292017 CS 442 m  < 10 LD May 26, uncertainty +/- 24 mins. - DOU



Notes: Ten times the distance to the Moon (ten LD) has no astronomical importance but is a useful boundary for reporting on transient natural objects that approach the actually significant gravitational sphere of influence (SOI), which has a radius of about 2.41 LD from Earth's center. This puts a focus on some of the most important and very best NEO observation work, representative of the much larger NEO discovery and tracking effort. Object distances are derived 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 21 February '17

The MPC's NEO Confirmation Page has 51 listings

When last checked at 2358 UTC today, the Minor Planet Center's Near Earth Object discovery Confirmation Page (NEOCP) had 51 objects listed. Of these, 33 were "one nighters." So far The Tracking News has counted a total of 67 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 February '17

Minor Planet Electronic Circulars

As of last check at 2358 UTC, there has been one MPEC posted today from the International Astronomical Union's Minor Planet Center in Cambridge, Massachusetts.


<< DOU on 21 Feb. '17 >>  MPEC 2017-D24 - "13:05 UT" - Daily Orbit Update

Observers  on 21 February '17

Eighteen observers appear in today's MPEC.

CodeObserver / observatory
H21Astronomical Research Obs. Westfield in Illinois, 13 in MPEC 2017-D24 -- 2017 BY93, 2017 BN91, 2017 BM123, 2017 AC5, 2016 UU80, 2016 QC84, 2012 JS17, 2003 CR1, 90075, 370307, 326683, 203471, 3352
T05ATLAS Haleakala in Hawaii, 3 in MPEC 2017-D24 -- 5626, 4055, 887
T08ATLAS Mauna Loa in Hawaii, 7 in MPEC 2017-D24 -- 2017 BY93, 90075, 153951, 138846, 138155, 10636, 1036
C77Bernezzo Obs. in Italy, 2 in MPEC 2017-D24 -- 2017 CP1, 2011 WO41
160Castelmartini Obs. in Italy, 13 in MPEC 2017-D24 -- 2017 CP1, 2016 UU80, 2011 UU106, 2001 QE34, 96590, 54789, 443103, 310842, 24445, 12538, 10165, 5693, 5131
807|Robert Holmes in Illinois via Cerro Tololo Inter-American Obs. (CTIO) in Chile, 9 in MPEC 2017-D24 -- 2017 CW1, 2017 CS, 2017 CG1, 2017 BV6, 2017 BQ93, 2017 BM92, 2017 BL123, 2016 WR3, 2016 TX55
K78Iota Scorpii Obs., 3 in MPEC 2017-D24 -- 138846, 5653, 5131
H06#M. Suzuki in Japan via iTelescope Obs. Mayhill in New Mexico, 1 in MPEC 2017-D24 -- 2008 CA6
Q62iTelescope Obs. Siding Spring in New South Wales, 1 in MPEC 2017-D24 -- 2002 EM6
Q622Marian Urbanik in Slovakia via iTelescope Obs. Siding Spring in New South Wales, 2 in MPEC 2017-D24 -- 2017 CP1, 2017 BY93
Q62|Sergio Foglia in Italy via iTelescope Obs. Siding Spring in New South Wales, 1 in MPEC 2017-D24 -- 2017 BL30
W86LCOGT Cerro Tololo B in Chile, 1 in MPEC 2017-D24 -- 2017 BY93
474Mt. John Obs. in New Zealand, 7 in MPEC 2017-D24 -- 2017 CQ1, 2017 CP32, 2017 BY93, 2017 BP31, 2017 AO13, 2016 YP4, 2008 EE68
W25RMS Obs., 6 in MPEC 2017-D24 -- 2017 DE, 2017 CF32, 2017 BY93, 2017 BM123, 370702, 138155
691Spacewatch 0.9m telescope in Arizona, 16 in MPEC 2017-D24 -- 2017 CS, 2017 BN3, 2017 BL6, 2017 BL30, 2017 BL123, 2017 AM4, 2017 AG5, 2016 XH2, 2016 XD1, 2016 WF9, 2012 RG3, 2012 BB124, 2009 UN3, 438955, 433953, 152563
291Spacewatch 1.8m telescope in Arizona, 7 in MPEC 2017-D24 -- 2017 CQ, 2017 BS31, 2017 BR31, 2017 BL30, 2017 BA30, 2012 UR136, 2002 SR
I52Steward Obs. Mt. Lemmon Station in Arizona, 5 in MPEC 2017-D24 -- 2017 DC, 2017 CQ32, 2017 BN123, 2017 BD29, 414990
Z52The Studios Obs., 1 in MPEC 2017-D24 -- 5653
T12UH/Tholen NEO Follow-Up 2.24m Telescope in Hawaii, 1 in MPEC 2017-D24 -- 2016 WF9
I15Wishing Star Obs. in Rhode Island, 7 in MPEC 2017-D24 -- 2017 CR32, 2017 CP1, 2014 EW24, 2011 WO41, 54789, 481904, 479325
For a list of all participating observatories that have Web addresses, see A/CC's Observatory Links page.

Impact Risk Monitoring  on 21 February '17

Summary Risk Table for Risk Assessments Updated Today   (last checks: NEODyS and JPL at 2358 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.
0000NNN000

Object

Risk
Monitor
When
Noted
UTC
0000T0000
Year
Range

VI
#
000NN00
Prob
Cum
T0000
PS
Cum
T0000
PS
Max

T
S


Notes for Today's Latest Risk Assessments
2017 CA33NEODyS15352043-2116159.53e-10-8.43-9.050NEODyS: "Based on 6 optical observations (of which 0 are rejected as outliers) from 2017-02-04.521 to 2017-02-06.288."
2017 CY32NEODyS15352047-209341.2e-08-9.14-9.390NEODyS: "Based on 18 optical observations (of which 0 are rejected as outliers) from 2017-02-01.401 to 2017-02-01.528."
2017 BF136NEODyS15352040-208144.89e-09-8.52-8.940NEODyS: "Based on 14 optical observations (of which 1 are rejected as outliers) from 2017-01-31.335 to 2017-02-01.370."
2017 BE136JPL Sentry18072025-2116191.1e-08-7.18-7.880JPL: "Analysis based on 7 observations spanning .90380 days (2017-Jan-30.42534 to 2017-Jan-31.329142)." Diameter approximately 0.067 km. from mean, weighted H=23.6.
2017 BY93NEODyS1807207019.76e-09-6.90-6.90NEODyS: "Based on 127 optical observations (of which 1 are rejected as outliers) from 2017-01-26.500 to 2017-02-21.123."
2017 BL30NEODyS18072029-2116154.56e-05-3.09-3.090NEODyS: "Based on 205 optical observations (of which 0 are rejected as outliers) from 2017-01-28.379 to 2017-02-21.279."
JPL Sentry16302029-205245.6e-06-4.01-4.010JPL: "Analysis based on 205 observations spanning 23.900 days (2017-Jan-28.37792 to 2017-Feb-21.27827)." Diameter approximately 0.072 km. from mean, weighted H=23.4.
2009 VZ39JPL Sentry05152017-21149237.0e-06-6.23-7.610JPL: "Analysis based on 8 observations spanning .04342 days (2009-Nov-10.27204 to 2009-Nov-10.31546)." Diameter approximately 0.009 km. from mean, weighted H=27.9.

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 21 February '17

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

1807Noted that JPL Sentry has posted 2017 BE136 as an impact risk - see above
Noted that NEODyS has updated its 2017 BL30 risk assessment - see above
Noted that NEODyS has updated its 2017 BY93 risk assessment - see above
1748Generated Traffic Report
1630Noted that JPL Sentry has updated its 2017 BL30 risk assessment - see above
1535Noted that NEODyS has posted 2017 BF136 as an impact risk - see above
Noted that NEODyS has posted 2017 CA33 as an impact risk - see above
Noted that NEODyS has posted 2017 CY32 as an impact risk - see above
Grabbed MPEC 2017-D24 - Daily Orbit Update - see above
0515Noted that JPL Sentry has updated its 2009 VZ39 risk assessment - see above