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

Today's issue status: done

• News briefs – precovery, radar observing
  & meteor news
• Risk monitoring – JPL has removed 2004 MS1 & NEODyS has reposted 2004 MX2

Cover: Today the half-kilometer-long 25143 Itokawa (1998 SF36) is passing five lunar distances from Earth. It was the target of a radar observing campaign during 17-22 June as a science opportunity in itself and to help prepare the arrival one year from now of the MUSES-C Hayabusa sample return mission. At left is a rendering/wireframe blend of Steve Ostro's Itokawa 3D shape model derived from 2001 radar observation (available here, see six-way view).

Precovery:  MPEC 2004-M54 reported yesterday that Centaur 2003 QD112 had been found in archived NEAT/Palomar images from 20 and 29 August and 15 September 2002, more than tripling the observing arc. Reiner Stoss (Index), who made this find, notes that this object's perihelion distance and date (7.940 AU on 26 May 1998) means that it was too faint to appear in Digitized Sky Survey archives, but “fortunately SkyMorph has NEAT imagery from this period.”

Radar observing:  Jean-Luc Margot told the Minor Planet Mailing list (MPML) this last week that astrometry and photometry would be helpful in preparing for radar observation of 1999 MN at Goldstone and Arecibo in early and mid-July. He notes that this is part of a radar study of “high-e low-a” asteroids — those with eccentric orbits and low average distances from the Sun. In the last two weeks, the big radar target was 25143 Itokawa, shown on the cover above. Goldstone will soon close for maintenance that is planned to last until December.

Meteor news:  The Missouri Kansas City Star reports today that a boom “heard — and felt — on the morning of June 19,” which “Some NASA experts thought . . . was the sound of a meteorite exploding in the atmosphere,” has turned out to have been the sonic boom of a fighter jet. Update: This was picked up as an AP wire story and appeared at USA Today June 28th.

Sandia National Labs has posted a movie (505Kb) of a bright meteor flash over Albuquerque, New Mexico at 3:11am MDT yesterday [not today, as originally reported–Ed.], the first since several earlier in the month, up through the 13th (see a composite from 2-13 June).

Risk monitoring 26 June

The Saturday Daily Orbit Update MPEC has observation of 2004 MS1 from Francisquito Observatory in southern California yesterday morning and KLENOT in the Czech Republic last night. Today JPL removed its only impact solution for this small object.

KLENOT picked up 2004 MX2 early today, and now NEODyS has reposted this half-kilometer object while JPL has raised its risk ratings. The two risk monitors have converged on similar two-solution assessments.