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

Today's issue status: done

• News briefs – meteor news
  Cover story by Peter Jenniskens
  panel 2 – occultation news + bits & pieces
• Risk monitoring – JPL has posted 2004 ME6, SCN 2004 ME6 observing campaign & NEODyS/JPL have removed 2004 MX2

Cover: A burst of June Bootid meteors caught by Peter Jenniskens with a video camera in Mountain View, California during 0730-1200 UT on June 23rd. Six meteors are composited into the full image, in which lines were drawn back to the radiant, and the stars beta Bootes and beta Ursae Majoris are labeled for reference. The uncropped image is available as the 458Kb original or a 135Kb version. See “Cover story” below, a similar report at the Leonid MAC site, and Marco Langbroek's report yesterday.

Meteor news:  Science@NASA has an item from June 25th about “unusually good” prospects for a good show from this year's Perseids meteor shower, which begins in mid-July and peaks during the night of 12-13 August in a dark sky, and may also have “a surge of mostly-faint meteors over Europe and Asia” at 2100 UT on the 11th (5pm EDT). See also Esko Lyytinen's prediction (2004 update at bottom).

The Warrnambool, Victoria Standard tells today about something that went thump in the night “a couple of metres” from a Terang resident who was outside tieing up his dog after being awakened by his cat falling out of a tree around 3am (we're not making this up). And the next morning he dug out what he thinks is a small meteorite (pictured). When contacted for help, a chap at the Bureau of Meteorology is quoted as saying that the only thing he knew about meteorites was that "every 30-odd million years one the size of Warrnambool hits and wipes all of us out."

more news >>

Cover story  by Peter Jenniskens, SETI Institute

An outburst of June Bootid meteors was observed from about June 22 19h UT until June 24 01h UT (ZHR > 1/hr), peaking at a rate of ZHR ~ 30/hr at 11±2 h UT, June 23. The meteors were mostly yellow in color, and the three low-resolution spectra recorded by me show a strong sodium line, a weak magnesium line, and a continuum with a relatively small contribution from the first positive system of N2.

The event was predicted by Sergey Shanov and Sergey Dubrovsky, and also studied by Mikiya Sato and Jeremie Vaubaillon, the latter at IMCCE, and is the result of Earth passing through a cluster of dust trails of 7P/Pons-Winnecke ejected in the returns of 1819, 1825, and 1830. The theoretical radiant was calculated at RA = 223.0, Decl. = +47.1 (Vg = 14.14 km/s) by Sato.

The figure [cover above, full image] is a compilation of my video records of the outburst. These meteors are small samples of comet 7P/Pons-Winnecke that spent less than 200 years in interplanetary space.

See also Peter Jenniskens' report and original 458Kb JPEG.

<< continued from panel 1

Occultation news:  David Dunham has posted a brief account of very successful observation of a star being occulted by Main Belt asteroid 302 Clarissa, video-recorded from six locations in the northeastern United States during the night of 23-24 June. Michael Richmond has posted a detailed report with images from his participation, along with a message from Dunham about preliminary results. It says that they measured an “ellipse 64 km long by 35 km wide, considerably bigger than the expected diameter of 38 km,” and they may have found a satellite on “the order of 5-6 km in size.” Wm. Robert Johnston's lists of known and suspected binary asteroids don't show that anyone had thought 302 Clarissa might have a satellite. And Sky & Telescope says today that, if confirmed, this “would become the first” asteroid discovered to be binary from observing an occultation.

Bits & pieces:  The Rosetta comet mission has posted a status report dated today for 18-25 June, “Testing Availability of MGA-S Antenna,” which may be needed “in case of Survival Mode triggering.”

Wildfire season has begun for observatories in the southwestern U.S., as evidenced by this today at the Tucson Arizona Daily Star: “Fire 6 miles from UA scopes.” It tells about a fire “burning roughly six miles west-northwest of the telescope complex atop Mount Graham,” but not yet posing a threat to the international facility.

Risk monitoring 28 June

The Monday Daily Orbit Update MPEC carries observations of 2004 MX2 from yesterday morning from McCarthy Observatory in Connecticut and Camarillo Observatory in southern California, and this morning from Great Shefford Observatory in England. And today both NEODyS and JPL removed their last impact solutions for this half-kilometer object.

Small object 2004 ME6, which isn't reported observed, was posted today to the European Spaceguard Central Node (SCN) Priority List as Level 1 “Urgent,” and noted as being in view until October 16th. SCN today also posted an observing campaign, noting that, “if further data is not achieved within a week, 2004 ME6 is very likely to be lost.” It will brighten to “magnitude 20.6 V in July,” but is currently “at magnitude 21.0-21.5.”

Update:  JPL has now posted 2004 ME6 based on the discovery observation arc of less than 21 hours.