| Sunday | 1 August 2004 | 5:06pm MDT | 2004-08-01 UTC 2306 |
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The Asteroid/Comet Connection's Today's issue status: done
Cover: Earth co-orbital 54509 2000 PH5 [link|alt] observed last Monday morning (July 26th) by Pepe Manteca at Begues Observatory in Spain (north is up and east left). See the A/CC cover that day for more info and his imagery of this small object from a year ago, and see below for this week's observing record. |
| Small objects – panel 1/2 | Major News for 1 Aug. 2004 |
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Small objects With nights still short in the northern hemisphere, where most NEO observing is done, and with the Moon interfering as it brightened to full yesterday, there is little to report this past week for observation of small asteroids (defined at right). One discovery was announced on July 27th, and two other objects were followed, including the only numbered small asteroid. Fourteen observatories participated in the week's work. The discovery came from Michael Van Ness at LONEOS in Arizona thirteen days after 2004 OW10 passed Earth at 4.6 lunar distances (LD). No close passes are predicted for August. In last week's report, some older observations credited to MPC code J50 for “La Palma-NEON” were described as coming from the Network of European Observatories in the North (NEON) Archive Observing School. That was an error. A/CC has learned that the J50 code is assigned to the Nordic Near-Earth-Object Network of Spaceguard (NEON) which has a current run on the 2.5m Nordic Optical Telescope (NOT). Its observations previously had been coded with MPC#950, which is used generically for a variety of users of several La Palma telescopes.
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What’s so big about “small objects”? If an asteroid’s orbit brings it to within 0.05 astronomical units (AU) of Earth's orbit, it is categorized as “potentially hazardous” unless it has an absolute magnitude H greater than 22.0, which corresponds to a diameter on the order of 135
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| Small objects – panel 2/2 (table) | Major News for 1 Aug. 2004 |
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H = absolute magnitude (brightness), from which size is roughly estimated — m/yd = meters/yards — [cross index]
All objects had observations reported last week. Those on a light-blue background had observations from only before the week.
Object | Estimated diameter | JPL H | MPC H | Discovery H in MPEC |
Earth MOID | European Spaceguard Central Node priority/visibility/campaign |
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| 2004 OW10 Apollo | 43 m/yd | 24.50 | 24.5 | 24.4 2004-O39 | 0.00447 AU | Urgent, visibility ends 27 Aug. |
| NEW: 2004 OW10 flew past Earth at 4.6 lunar distances on July 12th and was discovered on July 25th by Michael Van Ness at LONEOS, was confirmed on 26 and 27 July by Sandlot Obs., and on 27 July by Mt. John Obs., and Table Mountain Obs., and was announced in MPEC 2004-O39 of 27 July. This object was also observed on 27 July by Wykrota Obs. and Mt. John Obs. It has an MOID of 0.008 AU with Mars. | ||||||
| 2004 HB39 Amor | 100 m/yd | 22.65 | 22.7 | 22.5 2004-H74 | 0.093466 AU | Useful, visibility ends 17 Aug. |
| 2004 HB39 was observed on 24 and 25 July by the Nordic Near-Earth-Object Network of Spaceguard (NEON) with the 2.5m Nordic Optical Telescope (NOT). | ||||||
| 54509 2000 PH5 Apollo | 107 m/yd | 22.51 | 22.7 | 21.9 2000-P32 | 0.001726 AU | |
| 54509 2000 PH5 was observed on 26 July by Camarillo Obs., Begues Obs. (see cover above), and McCarthy Obs., on 28 July by Powell Obs., Dresden Obs., and Jurassien-Vicques Obs., on 29 July by Herrenberg Obs., and on 31 July by Powell Obs. and Modra Obs. This object shares Earth's orbit and came within 5 LD of Earth on July 25th. See the July 26th cover for more info and links. Catchall Catalog entry (alternate). | ||||||
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| Risk monitoring - panel 1/1 | Major News for 1 August 2004 |
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Risk monitoring
 1 August  The Sunday Daily Orbit Update MPEC (DOU) has observation of 2004 OT11 from yesterday morning from Powell Observatory in Kansas and this morning from Pla D'Arguines Observatory in Spain and Great Shefford Observatory in England. Today NEODyS very slightly, and JPL slightly, lowered risk ratings for this kilometer-size object while both cut their impact solution counts by about two thirds. Today's DOU also has observation of 2004 NL8 from Powell yesterday morning and Pla D'Arguines this morning. Today NEODyS cut back to one impact solution and sharply lowered its risk assessment for this kilometer-size object. |
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