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

Today's issue status: done

• News briefs – SOFIA news + bits & pieces
• Risk monitoring
  – NEODyS & JPL have removed 2004 BG121

Cover: Confirmation imagery of comet C/2004 R2 (ASAS) from Gary Hug at Farpoint Observatory in Kansas yesterday morning, when “The comet was only about 7 degrees above the horizon.” This is cropped from a 30-sec. image made with a 0.4m LX-200 S/C telescope at f/6 with a SBIG STL1001e CCD camera. North is up and east is left.
      MPEC 2004-R48 yesterday made official the discovery of this comet, found by Grzegorz Pojmanski from Las Campanas in Chile and headed for perihelion at 0.11376 AU on October 7th according to the Minor Planet Center's first calculation. See news links yesterday.

SOFIA news:  NASA/Ames has a news release from yesterday (images), telling that, while sitting on the ground during the night of 18-19 August, the SOFIA airborne observatory 2.5m telescope made its “first look,” putting a “crisp” image of Polaris “on astronomers' computer screens inside the aircraft, demonstrating that the telescope's basic optical, mechanical and software systems all are functioning properly.” This test included SOFIA's first scientific instrument, the High-speed Imaging Photometer for Occultations (HIPO) that will be used to study, among other targets, comets and the atmospheres of distant Solar System objects such as Pluto.

Bits & pieces:  As probably every A/CC reader has learned by now from numerous news outlets, the Genesis solar wind sample return capsule recovery didn't go according to plan on September 8th (see, for instance, a JPL news release today). However, a U.S. Air Force news release from yesterday states that observation of the hypervelocity atmospheric entry (see news, “Meteor on queue”) went very well. Peter Jenniskens is quoted as saying, “The tracking was a little difficult because the craft came in a little higher than expected, but we were able to get the data we wanted.”

There article today at New Scientist, “Asteroid impact craters could cradle life,” and The Independent telling about a study of Haughton Crater on Devon Island in Canada's far north that “discovered that rocks inside the crater are more heavily colonised by microbes than the rocks outside the crater.”

The September issue of Distant EKOs has been posted with reference to a number of scientific papers, some available for download as preprints.

The University of Maryland Diamondback has an article from September 8th, “Cosmic curiousity: Michael A'Hearn, principal investigator for the Deep Impact mission.”

Risk monitoring 10 Sept.

The Friday Daily Orbit Update MPEC (DOU) has the first observation of 2004 RJ9 since its confirmation, reported from last night from Great Shefford Observatory in England. Today NEODyS slightly raised its low risk assessment toward converging with the JPL assessment, which was itself very slightly lowered.

The 2004 BG121 story took another turn today when NEODyS and JPL removed all impact solutions for this half-kilometer-plus asteroid. It was originally posted on 11 February based on observations from a period of almost eleven days, but the risk monitors soon unlinked the later observations reported in the discovery MPEC (2004-C38), leaving only Spacewatch 0.9- and 1.8-meter telescope observations spanning less than 23 hours. JPL removed its solutions then, but, until today, NEODyS had kept its assessment, including an impact solution for August 2nd next year, based on the nine original Spacewatch observations plus one other within the same arc.

Based on nine observations from the old observation arc, JPL reposted 2004 BG121 three days ago with a low-probability solution for August 1st next year. Yesterday JPL revised this assessment based on 14 observations, cutting

its solution count by more than two-thirds and eliminating solutions before 2009. Today's DOU has five Spacewatch 0.9m telescope observations from 11 and 14 February, boosting the observation arc to 14.963 days.