Most of Earth's oldest impact craters, even those from colossal collisions, have been lost due to weathering and tectonic forces. News releases April 25th from Purdue University and the Southwest Research Institute (SwRI) report that new tools allow these impacts to be studied through thin layers of spherules that condensed from plumes of vaporized rock thrown high above Earth, such as these examples, each about a millimeter wide, from Western Australia (Jeerinah layer) from an event with worldwide affects 2.63 billion years ago. Photo credit: Oberlin College/Bruce M. Simonson.
Contents on 27 April '12
- Traffic Report -- four objects
- IAU Minor Planet Center
- Observers -- sixteen observers
- Impact Risk Monitoring -- four objects
Asteroid/Comet Connection (A/CC) Resources:
- Consolidated Risk Tables - the CRT page (archive)
Of 456 risk-listed objects, 30 have had news in the last 31 days. Updated at 2259 UTC on 27 April.
- Ephemerides for risk-rated & nearby objects + potential mission destinations
- News image catalog
- News old archive & Small Objects Archive
- Object Links - mainly for radar targets & close passers - updated 18 April
- Observing Campaigns
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 April '12
Four objects reported inside ten LD
Four asteroids are reported traveling within ten lunar distances (LD) of Earth today. Inside Earth's Hill sphere, radar target 2012 HM moves from 2.50 to 1.57 LD and risk-listed 2012 HP13 comes its closest to Earth this time around, reaching 1.98 LD at 0625 UTC, as well as its closest to the Moon -- 1.10 LD at 1024 UTC.
Out further, risk-listed 2012 HG2 is outbound from 7.21 to 7.99 LD and 2012 HN1 from 8.43 to 9.40 LD.
Coming to the neighborhood next, 1992 JD arrives inside ten LD on April 30th and 2010 KK37 on May 15th.
This report was generated at 1312 UTC with follow-up in today's DOU MPEC for 2012 HP13 and 2012 HM.
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 April '12
The MPC's NEO Confirmation Page has 20 listings
When last checked at 2358 UTC today, the Minor Planet Center's Near Earth Object discovery Confirmation Page (NEOCP) had 20 objects listed. Of these, nine were "one nighters." So far The Tracking News has counted a total of 43 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 27 April '12
Minor Planet Electronic Circulars
As of last check at 2359 UTC, there has been one MPEC posted today from the International Astronomical Union's Minor Planet Center in Cambridge, Massachusetts.
- Observations of risk-listed objects
- K12H13P 2012 HP13 (small asteroid, arc=4 days, H=24.2 ~49m, close passer) from David Tholen's team on Mauna Kea (April 25.58p2), San Marcello Pistoiese Obs. (April 25.83-86p3), Castelmartini Obs. (April 25.97-98p4), Barred Owl Obs. (April 26.14-16p22), Pear Tree Obs. (April 26.19p3), Tim Lister via Faulkes Telescope North (April 26.33-34p17), and South Obs. (April 26.90-91p8)
- K12H08M 2012 HM8 (small asteroid, Q=4.683 AU, arc=5 days, H=23.9 ~56m) from Naef Obs. (April 26.85-88p4)
- K12H08G 2012 HG8 (Q=4.229 AU, arc=7 days, H=19.8 ~371m) from Mark Trueblood via Kitt Peak Natl. Obs. (KPNO) (April 27.18p4)
- K12G17V 2012 GV17 (arc=11 days, H=21.2 ~195m) from Tholen team/Mauna Kea (April 25.49-50p2 at R=22.2-3)
- Observations of close-passing objects
- K12H00M 2012 HM (arc=11 days, H=24.1 ~51m, radar support) from Castelmartini Obs. (April 25.97p3), Barred Owl Obs. (April 26.11-13p66), Lister/Faulkes North (April 26.31-32p22), and Trueblood/KPNO (April 27.17p4)
- Observation campaigns (radar support, potential mission destinations)
- K10K07X 2010 KX7 (arc=3 opp, H=21.7 ~155m, radar) from Galati Obs. (April 26.99p5)
-- Planetary radar schedules: Arecibo & Goldstone
- Observations of small asteroids (H>22.0)
- K12H00L 2012 HL (arc=10 days, H=22.7 ~98m) from Castelmartini Obs. (April 25.95-96p3)
- Observations of other asteroidal objects
- K12H20C 2012 HC20 (arc=2 days, H=21.5 ~170m) from Bisei Spaceguard Center (April 26.54-55p4)
- K12H13O 2012 HO13 from the Spacewatch 1.8m telescope (April 25.36p3)
- K12H01Y 2012 HY1 (arc=10 days, H=19.9 ~355m) from Pan-STARRS 1 (PS1) (April 26.40-41p2)
- K12H01M 2012 HM1 (arc=10 days, H=21.2 ~195m) from PS1 (April 26.40-41p2)
- K12G11X 2012 GX11 (arc=12 days, H=21.1 ~204m) from PS1 (April 26.59-60p2)
- K12D00O 2012 DO (arc=70 days, H=20.3 ~295m) from Castelmartini Obs. (April 26.02p3) and PS1 (April 26.42-44p2)
- K10L14J 2010 LJ14 (arc=2 opp, H=17.8 ~933m) from PS1 (April 26.59-60p2)
- K10C18G 2010 CG18 (arc=2 opp, H=20.8 ~234m) from PS1 (April 26.42-43p2)
- K09X08G 2009 XG8 (i=59.9°, arc=2 opp, H=18.8 ~589m) from Sandlot Obs. (April 26.41-42p3)
- K03SM2V 2003 SV222 (arc=5 opp, H=17.6 ~1.02 km) from PS1 (April 26.35-36p2)
- K03S05L 2003 SL5 (arc=4 opp, H=19.2 ~490m) from PS1 (April 26.40-41p2)
- K01SQ9Z 2001 SZ269 (arc=3 opp, H=19.6 ~407m) from Castelmartini Obs. (April 26.07p3)
- V2473 312473 2008 SX245 from Galati Obs. (April 26.87-88p18)
- S4114 284114 2005 TZ51 from Lohrmann Obs. (2008 Oct. 23.84-85p3)
- Q3976 263976 2009 KD5 from MASTER-II Obs. Kislovodsk (April 25.78-80p2)
- I9008 189008 1996 FR3 from PS1 (April 26.40-41p2)
- I6822 186822 2004 FE31 from PS1 (April 26.40-41p2)
- F2889 152889 2000 CF59 from PS1 (April 26.45-46p2)
- E4861 144861 2004 LA12 from PS1 (April 26.47-50p4)
- E1531 141531 2002 GB from Naef Obs. (April 26.90p1 & 26.94p1)
- D6874 136874 1998 FH74 from PS1 (April 26.41-42p2)
- 96590 96590 1998 XB from Lohrmann Obs. (2011 March 21.83p1 & 2011 March 21.87p2)
- 86667 86667 2000 FO10 from PS1 (April 26.40-41p2) and Galati Obs. (April 26.83-84p18)
- 66407 66407 1999 LQ28 from PS1 (April 26.45-46p2)
- 24475 24475 2000 VN2 from Galati Obs. (April 26.81-82p18)
- 10150 10150 1994 PN from PS1 (April 26.52-53p2)
- 07341 7341 1991 VK from PS1 (April 26.38-39p2)
- 01865 1865 Cerberus (1971 UA) from Lohrmann Obs. (2010 July 8.93-95p4)
- 01620 1620 Geographos (1951 RA) from Lohrmann Obs. (2008 Oct. 23.85p3)
Observers on 27 April '12
Sixteen observers appear in today's MPEC.
|Code||Observer / observatory|
|I27||Barred Owl Obs., 2 in MPEC 2012-H75 -- 2012 HP13, 2012 HM|
|300||Bisei Spaceguard Center in Japan, 1 in MPEC 2012-H75 -- 2012 HC20|
|160||Castelmartini Obs. in Italy, 5 in MPEC 2012-H75 -- 2012 HP13, 2012 HM, 2012 HL, 2012 DO, 2001 SZ269|
|F65%||Tim Lister in southern California via Faulkes Telescope North in Hawaii, 2 in MPEC 2012-H75 -- 2012 HP13, 2012 HM|
|C73||Galati Obs. in Romania, 4 in MPEC 2012-H75 -- 2010 KX7, 86667, 312473, 24475|
|695]||Mark Trueblood via Kitt Peak Natl. Obs. (KPNO) in Arizona, 2 in MPEC 2012-H75 -- 2012 HM, 2012 HG8|
|C01||Lohrmann Obs. in Germany, 4 in MPEC 2012-H75 -- 96590, 284114, 1865, 1620|
|C41||MASTER-II Obs. Kislovodsk in Russia, 1 in MPEC 2012-H75 -- 263976|
|5682||David Tholen's team on Mauna Kea in Hawaii, 2 in MPEC 2012-H75 -- 2012 HP13, 2012 GV17|
|A13||Naef Obs. in Switzerland, 2 in MPEC 2012-H75 -- 2012 HM8, 141531|
|F51||Pan-STARRS 1 (PS1) in Hawaii, 17 in MPEC 2012-H75 -- 2012 HY1, 2012 HM1, 2012 GX11, 2012 DO, 2010 LJ14, 2010 CG18, 2003 SV222, 2003 SL5, 86667, 66407, 189008, 186822, 152889, 144861, 136874, 10150, 7341|
|H23||Pear Tree Obs. in Florida, 1 in MPEC 2012-H75 -- 2012 HP13|
|104||San Marcello Pistoiese Obs. in Italy, 1 in MPEC 2012-H75 -- 2012 HP13|
|H36||Sandlot Obs. in Kansas, 1 in MPEC 2012-H75 -- 2009 XG8|
|J84||South Obs. in England, 1 in MPEC 2012-H75 -- 2012 HP13|
|291||Spacewatch 1.8m telescope in Arizona, 1 in MPEC 2012-H75 -- 2012 HO13|
|For a list of all participating observatories that have Web addresses, see A/CC's Observatory Links page.|
Impact Risk Monitoring on 27 April '12
Notes for Today's Latest Risk Assessments
|2012 HP13||JPL Sentry||2259||2077-2100||10||4.8e-07||-6.06||-6.64||0||JPL: "Analysis based on 150 observations spanning 4.4542 days (2012-Apr-22.46032 to 2012-Apr-26.91457)." Diameter approximately 0.050 km. from mean, weighted H=24.2.|
|NEODyS||1308||2069-2088||14||3.79e-07||-6.12||-6.75||0||NEODyS: "Based on 156 optical observations (of which 9 are rejected as outliers) from 2012-04-22.461 to 2012-04-26.915."|
|2012 HM8||JPL Sentry||1308||R E M O V E D||JPL: Risk listing removed at 0850 UTC.|
|2012 HG8||JPL Sentry||1308||2030||1||1.7e-06||-2.50||-2.50||0||JPL: "Analysis based on 133 observations spanning 6.9249 days (2012-Apr-20.25484 to 2012-Apr-27.17974)." Diameter approximately 0.370 km. from mean, weighted H=19.8.|
|NEODyS||1308||2030-2030||1||6.48e-07||-2.93||-2.93||0||NEODyS: "Based on 134 optical observations (of which 1 are rejected as outliers) from 2012-04-20.256 to 2012-04-27.181."|
|2012 GV17||NEODyS||1308||2035-2090||30||1.51e-07||-4.92||-5.21||0||NEODyS: "Based on 28 optical observations (of which 0 are rejected as outliers) from 2012-04-14.343 to 2012-04-25.499."|
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 April '12
Times are UTC for when items were noted or added by The Tracking News.
|2259||Noted that JPL Sentry has updated its 2012 HP13 risk assessment - see above|
|1312||Generated Traffic Report|
|1308||Noted that NEODyS has updated its 2012 GV17 risk assessment - see above|
Noted that JPL Sentry has updated its 2012 HG8 risk assessment - see above
Noted that NEODyS has updated its 2012 HG8 risk assessment - see above
Noted that JPL Sentry has removed 2012 HM8 as an impact risk - see above
Noted that NEODyS has updated its 2012 HP13 risk assessment - see above
Grabbed MPEC 2012-H75 - Daily Orbit Update - see above