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

Today's issue status: done

• News briefs – meteor news & NEKAAL Tombaugh Telescope
  panel 2 – IEO news
• Risk monitoring – NEODyS & JPL have removed 2004 KB & NEODyS has removed 2004 HQ1
  + JPL has revised ratings for several objects not under current observation

Cover: PHO 2004 JQ1 is roughly estimated from its brightness to be about 400 meters/yards wide. Here it is observed (at about mag. 20) by Francesco Manca and Marco Cavagna at Sormano Observatory on May 17th, two days after it was removed from the risk monitors' lists. Two more objects were removed from those lists today, as reported below.

Meteor news:  An Arizona State University (ASU) news release today (also here) announces an article in tomorrow's edition of Science, “The Cradle of the Solar System” by Jeff Hester and other ASU astronomers and meteorite scientists. Instead of a “fairly quiescent process in which an undisturbed molecular cloud slowly collapses,” forming stars here and there, they argue that the Sun formed in a more massive region with “not only low-mass stars, but luminous high-mass stars.” They base this on observation and meteorite chemistry, specifically “the recent discovery in meteorites of patterns of isotopes that can only have been caused by the radioactive decay of iron-60, an unstable isotope that has a half life of only a million and a half years. Iron-60 can only be formed in the heart of a massive star and thus . . . provides strong evidence that when the Sun formed (4.5 billion years ago) a massive star was nearby.” This scenario also might explain “why the outer part of the Solar System — the Kuiper Belt — seems

to end abruptly.” There are some excellent illustrations, and Space.com has a report today.

The Sandia all-sky camera in Albuquerque, N.M. caught a bright meteor flash nearly overhead at 10:05pm MDT last night (Quicktime 452Kb movie).

more news >>

<< continued from panel 1

IEO news:  Lowell Observatory has a news release today, “LONEOS Discovers Asteroid with the Smallest Orbit,” telling about 2004 JG6: “2004 JG6 goes around the Sun in just six months, making it the asteroid with the shortest known orbital period" and "is the second closest solar system object orbiting the Sun." Only Mercury has an average orbital distance (semimajor axis) closer to the Sun. See an accompanying JPEG orbital diagram, A/CC's May 14th report, and the JPL orbit viewer.

Risk monitoring 20 May

The Thursday Daily Orbit Update MPEC (DOU) has observation of 2004 KB by Tenagra II Observatory in Arizona yesterday morning and last night by KLENOT in the Czech Republic and Sormano Observatory in Italy. Today both NEODyS and JPL removed all of their impact solutions for this quarter-kilometer object.

And the DOU carries positions for 2004 HQ1 reported from the Spacewatch 1.8m telescope in Arizona early yesterday UT (night of the 18th local time). Today NEODyS removed its last solution for this object estimated to be on the order of 80 meters/yards wide.

Update:  JPL today removed two listings without new observations reported. Both had had a single JPL low-rated impact solution left, and both are small: 1998 WD31 is estimated at about 110 meters wide and 2002 AN129 at about 20 meters. (NEODyS has one very low rated solution for 1998 WD31.)

Update #2:  Also based on existing observation arcs, JPL has revised its risk assessments for three other objects long out of view. It has revised its 1998 HJ3 ratings, going from two to three impact solutions next century, has posted 1998 BT13 with one very low rated solution, and has reposted with a single low-rated solution 2002 GJ8, which it had previously listed during 18 April to 4 May 2002. 1998 BT13 is a small object, estimated at about 20 meters wide.