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

Today's issue status: done

• News briefs – comet, precovery & meteor news + Deep Impact news
• Risk monitoring – NEODyS has posted 2004 GU9
  + 2004's 2nd amateur-discovereed NEO (2004 GA1) has VIs + NEODyS & JPL have removed 2004 GB2

Cover: An L5 chondrite Park Forest meteorite from the Chicago area March 2003 event, showing some "yellow paint that it picked up on impact." Photo by Elliott Brennan, courtesy of the University of Illinois. See that link for yesterday's news about analysis of the event. It is reported that the strewn field does not line up with satellite entry data, apparently due to strong winds.

Comet news:  C/2004 F4 (Bradfield) is now visible in SOHO LASCO C3 images, entering as a bright "bump" at bottom, slightly left of center on the frame edge, beginning with the 2018 UT frame of the 15th. The SOHO mission has posted a preview of how the comet will move up through the frame in coming days. There are a number of URLs from which to watch, including the latest LASCO C3 images page. (Thanks to Sebastian Hoenig for the news tip.)

For the second day in a row (see yesterday), an asteroidal object has been redesignated as "comet Catalina-LINEAR," this time P/2004 EW38 (Catalina-LINEAR), reported in MPEC 2004-G46 with perihelion last November 19th out past Mars.

Precovery news:  MPEC 2004-G45 today reports that Giussepi Forti located 2004 FC32 in digitized plates from the Mt. Palomar 1.2m Schmidt telescope from 16 and 22 March 1996. FC32 was announced yesterday in MPEC 2004-G33 without discovery credit but showing observations from that same telescope

on April 8th as well as from the Catalina Sky Survey (CSS) in Arizona March 18th and April 14th, and from LINEAR in New Mexico on 30-31 March. As NEOs go, it is distant, with perihelion at 1.26 AU on an eccentric orbit (e=0.3393). From its brightness, it could be from 600 to more than a thousand meters/yards wide, with best standard rough estimate around 700.

Meteor news:  A JPL news release today tells of the Mars rover Opportunity examining "an odd volcanic rock on the plains of Mars' Meridiani Planum region with a composition unlike anything seen on Mars before, but scientists have found similarities to meteorites that fell to Earth." Named "Bounce Rock," it resembles shergottites found in India and Antarctica.

Deep Impact:  Space.com has an article today, "On the Edge: Creating a Crater in Space." It reports that the Deep Impact mission, in presuming that the flyby spacecraft will likely survive next year's July 4th 9P/Tempel 1 encounter, plans to formally propose to NASA extending the mission to visit "other comets and asteroids," with 103P/Hartley 2 at top of the list.

Risk monitoring 15 April

The year's second amateur-discovered near-Earth asteroid is a big one, and was soon posted to the JPL Current Impact Risks page. 2004 GA1 was announced today in MPEC 2004-G43 as discovered by John Broughton at Reedy Creek Observatory in southeasternmost Queensland, Australia on Sunday. He and the Siding Spring Survey (SSS) at Siding Spring caught it again on Monday, and it was further confirmed by six other observatories yesterday and this morning. JPL puts the diameter at 1.13 km. (0.7 mile).

The Thursday Daily Orbit Update MPEC (DOU) reports three positions for 2004 GB2 from early yesterday from the Spacewatch 1.8m telescope in Arizona, and today NEODyS and JPL both removed their few impact solutions for this object.

The DOU also has observation of 2004 GU9 early yesterday from LINEAR in New Mexico, and JPL today cut its count of impact solutions for this object while slightly raising its overall risk ratings.

Update:  NEODyS has now posted 2004 GU9.

Follow-up:  Brigitta Sipocz tells A/CC that it was Krisztian Sarneczky at the Szeged University (SZTE) Asteroid program who found the additional positions in archives for 2001 FB70 reported yesterday.

Today's DOU shows radar observation of 2004 FY31 on April 14th from Arecibo in Puerto Rico. This object was listed with impact solutions from March 31st to April 3rd. JPL's current absolute magnitude calculation of H=21.89 converts to a diameter of roughly 140 meters/yards. It passed Earth at 12.1 lunar distances on the 10th.