The Asteroid/Comet Connection's
daily news journal about
asteroids, comets, and meteors

Today's issue status: done

• News briefs – meteor news
  News from Cloudbait by Chris Peterson
• Risk monitoring
  – NEODyS has posted 2004 MO7 & 2004 MP7

Cover: In early daylight 96 years ago today, Earth took its largest documented cosmic hit in historic times, from what is believed to have been a stony asteroid, perhaps 30 to 60 meters/yards wide, or a somewhat larger comet piece. The aerial explosion destroyed trees over an area the size of Rome in a very remote region of Siberia northwest of Lake Baikal, in what is now the Tychansky Natural Reserve in the Evenkia Autonomous Area of the Russian Federation. At left, courtesy of the University of Bologna Tunguska site, is an aerial photo from a 1938 survey by Leonid Kulik, a recent photo showing the swampy terrain, and a map of the site.

Meteor news:  Australian Broadcasting said today that Perth Observatory and Western Australia Museum have reports of a phenomenon “somewhere between Perth and Albany” in southern Western Australia at around 5:30pm Tuesday, flying toward the south-southeast. Although described as “zigzagging,” authorities maintain it was probably a meteor. At last check, this event hasn't appeared elsewhere in Australian news media. Marco Langbroek reports that there were no suitable orbital decay candidates to explain the sightings.

The New Zealand Otago Daily Times has an article from June 28th with more from two eyewitnesses to a fireball Saturday night who were mentioned in a Stuff.co.nz article linked from A/CC's Sunday report.

News from Cloudbaitby Chris Peterson

The Sandia camera in Albuquerque, New Mexico captured a very impressive fireball, magnitude -10.9, at 0311 MDT on 25 June (505Kb). This was also captured on my camera, allowing me to locate the terminal explosion about 40 miles (65 km.) NNW of Albuquerque.

I have a good witness report describing a Sunday 0415 CDT (0915 UTC) fireball seen to the east of Refugio, Texas. It sounds like there was a lot going on Sunday morning [see “More meteors”].

I also received several witness reports of a fireball on 26 June, with times ranging from 2230 to 2250, and ranging from Pennsylvania to Michigan. These presumably were of the Russian rocket decay. I normally only receive multiple reports of events this far from Colorado when they are very impressive. [See “Russian rocket.”]

Chris Peterson in Guffey (in central Colorado) is a science teacher, amateur astronomer, and the Colorado state coordinator for fireball reports and a network of school-based all-sky cameras.

Risk monitoring 30 June

Today NEODyS posted 2004 MO7 and 2004 MP7, new discoveries that were announced after 2230 UTC yesterday and posted after midnight UTC by JPL.

MPEC 2004-M67 announced that 2004 MP7 was discovered early Saturday by amateur astronomer Roy Tucker at Goodricke-Pigott Observatory in Arizona, where he uses an unusual homebuilt setup consisting of three fixed-mount 0.35m telescopes that operate in continuous drift-scan mode. He points out to A/CC that John Broughton at Reedy Creek Observatory in Queensland, Australia deserves “special recognition” for achieving a very difficult first confirmation, as the “uncertainty region had grown to enormous dimensions by the time he snagged it” yesterday, more than three days (75.92 hours) later. The Observatorio Astronomico de Mallorca (OAM) closed out the confirmation last night. And the Wednesday Daily Orbit Update has positions reported from last night from OAM as well as Modra Observatory in Slovakia.

The MPC is showing that 2004 MP7 passed 11.7 lunar distances from Earth on Thursday, June 24th.

2004 MO7 was announced in MPEC 2004-M68 as discovered by David Tholen and Fabrizio Bernardi early on June 16th from Mauna Kea in Hawaii, using, Tholen tells A/CC, the Japanese 8.2m Subaru Telescope. They picked it up again 24.7 hours later, and then confirmed it with the 2.3m Bok Telescope at Kitt Peak in Arizona on the 19th and 20th (MO7 hasn't been reported seen since ten days ago).

By a great coincidence, the Bok operator and designated principal investigator was Roy Tucker,

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whose day job is “CCD characterization engineer at the University of Arizona's Imaging Technology Laboratory,” which among other tasks provides technical support to Kitt Peak. He says, “even though I am strictly-speaking a university staff member at the CCD lab and not a professional astronomer, I found myself in the sweet position of observing asteroids with a 90" telescope. . . I wasn’t getting paid for it and I was taking vacation time to do it, but I wasn’t complaining.” A/CC will have a lot more about all of this tomorrow.

These obviously are not “run of the mill” NEO discoveries. One rarely sees very large telescopes used for NEO follow-up, let alone discovery, and 2004 MP7 is only the third amateur-discovered NEO this year, and the second to appear on the risk monitors' lists (the other was 2004 GA1, discovered by John Broughton at Reedy Creek).