Oct. 2003 Asteroid/Comet/Meteor News
Updated: 20 January 2004
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The Heber Springs, Arkansas Sun-Times had an Oct. 3rd article, "Local recalls falling of Miller Meteorite." The fall was witnessed on 13 July 1930, and the meteorite, weighing 13.7 kg. (36.6 lbs.), landed "about fifty yards" from an occupied house in what is now Greers Ferry in north-central Arkansas. "1930 Arkansas" may ring a bell, since A/CC told earlier about another, larger meteorite that fell about 80 miles (130 km.) away, near a house in the state's northeastern corner on February 17th of the same year. The Miller Meteorite is now in the collection of the American Museum of Natural History (AMNH) in New York City.
8 October 2003
The Minor Planet Center updated its Discovery Circumstances pages on Oct. 8th with namings for 69 LINEAR-discovered asteroids, from 19550 Samabates (1999 JP61) to 19835 Zreda (2000 SQ252). No new numberings were issued for asteroids, but the Periodic Comet Numbers page was updated with 1978 C2=2003 T1 newly numbered as 157P/Tritton.
18 October 2003
Spacewatch has a new FMO Project to involve the public in observing runs with its 0.9 telescope by having them watch for fast-moving objects (FMOs) that cannot be easily or reliably detected by software automation. Discovery and recovery credits will be given. "The only requirements for participation in the FMO project are 1) interest, 2) sharp eyes and 3) access to a computer during the hours that the Spacewatch mosaic system [CCD camera] is in operation." A broadband Internet connection is recommended, along with 1280x1024 screen resolution and a 19" monitor. "Knowledge about astronomy" is "Useful (but not necessary)." The site includes a tutorial that should be interesting even for those who don't participate, and further help is available for those who do.
After more than three weeks of news about bolides seen around the globe and about tiny globe-buzzing asteroids, the big question is, Has Earth encountered some kind of minor object stream? It has even been suggested that all this activity could be associated with fireballs seen last September and October, as if Earth is on its second pass through a field of space boulders. In regard to just two events separated by a few hours, one over California and another over Europe, a San Jose Mercury article of September 30th quoted Peter Jenniskens, who studies such streams for NASA, as saying "maybe we have a bit of a shower of bright fireballs going on at the moment."
See also a Planetary Society Oct. 2nd article, "Meteors Raining From the Sky," summing up the 23-29 September run of worldwide meteor news.
2003 UC20 & 1954 XA
On Oct. 23rd, MPEC 2003-U55 announced 2003 UC20 as discovered by LINEAR on the 21st and followed up on the 22nd by LINEAR with Table Mountain and Tenagra II observatories, and on the morning of the 23rd by Table Mountain. From its brightness (H=19.3), 2003 UC20 was estimated to be on the order of 475 meters/yards wide.
The orbital elements for 2003 UC20 bear some resemblance to those of 1954 XA. Attempts to link the two apparitions have not been successful, although a number of dynamical routes that allow 2003 UC20 to make a close Earth approach in 1954 have been identified. Further observations are very desirable. 1954 XA was discovered by George Abell at Mt. Palomar on 5 Dec. 1954, and was only observed once more, six days later, according to the NEODyS observation tally and 1954 XA's entry in the EARN database. Although not seen since, 1954 XA is often included in NEO lists, and is on Lowell Observatory's Orbit intersections list as a potentially hazardous object (PHO). The discovery MPEC did not categorize 2003 UC20 as a PHO.
Later the same day, on Oct. 23rd, MPEC 2003-U56 reported additional observations of 2003 UC20 by LINEAR that morning and announced a correlation, 2003 UC20 = 1954 XA, "based upon a successful linkage of the 1954 and 2003 observations by A. Lowe," who achieved this by discarding one of two "problematic" 1954 XA observations from 11 Dec. 1954.
Not initially categorized as a potentially hazardous asteroid (PHA), the various PHA lists by Oct. 25th included 2003 UC20. Astrometric and photometric optical observations were requested to help prepare for radar observation from Arecibo in Puerto Rico during 28-31 October. The 25th's Daily Orbit Update MPEC carried 2003 UC20 observations from LINEAR and Table Mountain Observatory from the 24th, and Andrushivka Observatory in the Ukraine turned in a set of ten positions from the morning of the 25th.
Radar observations of 2003 UC20 from Arecibo were reported from Oct. 28th in the Daily Orbit Update MPEC (DOU) of the next day, and from the 30th in the DOU for Nov. 1st.
SOHO ends public participation
After about 650 discoveries, with some 100 still unreported to the IAU, SOHO comet hunting has now come to a halt. Derek Hammer, the last of the ESA/NASA mission staff members who used to confirm, measure, and report discoveries to the Minor Planet Center (MPC), on August 4th posted his final message to the SOHO-hosted chat page for announcing and confirming SOHO comet discoveries.