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

Today's issue status: done

• More about 2003 VB12 Sedna
• News briefs
  – distant objects & Space resources meeting
  Part 2 – comet news & major object news
• Risk monitoring – JPL has posted 2004 EW9

Cover: Images from the 2003 VB12 Sedna discovery from the 1.2m Oschin Telescope on Mt. Palomar on 14 November 2003 with the Quest II camera, observers Mike Brown, Chad Trujillo, and Dale Rabinowitz. Images courtesy of Spitzer Space Telescope (SST).

Daniel Fischer comments to A/CC that a lot of "nonsense has been broadcast and written about 2003 VB12, aka 'Sedna.'" It certainly seems to have been reported enthusiastically everywhere in the news media. For a good review of the facts, see his Cosmic Mirror report based in part on participating in yesterday's NASA telephoned news conference. And here are more news links:

• Science@NASA, "Mysterious Sedna"
• AFP on SpaceDaily, "Presenting Sedna, a far-flung planetoid of ice and rock"
• Sky & Telescope, "Far-Flung Planetoid Shatters Distance Record"
• Space.com, "Scientists Find Another Huge Mini-World in Outer Solar System"

The final confirmation observations of 2003 VB12 in yesterday's announcement MPEC 2004-E45 came from KLENOT in the Czech Republic on Sunday, and an image page has been posted there from that work.

See also today's cover and the cover and reports yesterday.

2003 VB12 orbit relative to inner (top left, with Earth and Main Belt) and outer Solar System (top right, with Pluto and Kuiper Belt), and to the theoretical inner Oort Cloud. See larger. Credit SST.

Distant objects:  The March 2004 edition of Distant EKOs was posted today. It reports a tally of 924 trans-Neptunian objects, from one Neptunian Trojan and 149 Centaurs and scattered-disk objects (SDOs) to 774 Edgeworth-Kuiper Belt objects (EKBOs), not including Pluto/Charon and 12 EKBO companions. And it notes that about half of these objects are in much need of further observation.

The issue brings to our attention a paper by Mike Brown and Chad Trujillo about imaging 50000 Quaoar with the Hubble Space Telescope High Resolution Camera "to directly determine its size" through angular resolution, coming up with 1260 km. +/- 190 km., and finding an albedo "significantly higher" than normally assumed. The preprint, a 169KB PDF available from Mike Brown, notes that Quaoar has a 20% lightcurve variation "over a period of many hours," likely caused by surface features.

That and a number of other described papers provide new insights into distant object surface

Space resources:  It was announced today that "The next Space Resources Roundtable [SRR] meeting will be held November 1-3 (end at noon) at the Colorado School of Mines, in Golden."

colors, which holds even more interest now that the reddest yet has been found, 2003 VB12 Sedna. Among other results, one paper says simultaneous optical and infrared observation with two 8m VLTs found a possible indication of water ice for 24835 1995 SM55.

And a paper by Scott Sheppard and David Jewitt tells about "Extreme Kuiper Belt Object 2001 QG298" as "the first known Kuiper Belt object and only the third minor planet with a radius >25 km to display a lightcurve with a range in excess of 1 magnitude." They suggest it "may be a very close or contact binary similar in structure to what has been independently proposed for the Trojan asteroid 624 Hektor." See Sheppard's 2001 QG298 page for more info and the preprint. (He also notes that the "peculiar" 1995 SM55 will be discussed in a coming paper on EKBO lightcurves.)

more news briefs >>

<< continued from part 1

Comet news:  The asteroidal object announced February 28th in MPEC 2004-D45 as discovered by the Spacewatch 0.9m telescope in Arizona, with observations 1.48 hours later by LINEAR in New Mexico and six days earlier by LONEOS in Arizona, was updated in MPEC 2004-F09 today. This new MPEC redubbed it comet P/2004 DO29 (Spacewatch-LINEAR) and showed observation by Catalina Sky Survey (CSS) in Arizona yesterday and by Scott Sheppard et al. this morning with the University of Hawaii 2.2m Telescope on Mauna Kea.

Major object news:  Space.com has an article today, "Distant Sedna Raises Possibility of Another Earth-Sized Planet in Our Solar System." It says the strange orbit of 2003 VB12 Sedna may be explained by 1) gravitational influences in the stellar nursery where our Solar System was born, close to dense clouds and other stars, or by 2) being perturbed by a very distant object with the mass of the Earth or larger. It says Brian Marsden doesn't like the first theory, and thinks it might have been a perturber at 400 to 1,000 AU. 2003 VB12 co-discoverer Mike Brown says his team's calculations put the perturber at about 70 AU. It may not have been noticed yet because it is in the bright region toward the galactic center, and "his team is considering making that search now."

Risk monitoring 16 March

For the first time since March 6th, there is an object under current observation that is listed with an impact solution. JPL today posted 2004 EW9, which was announced in MPEC 2004-F07 today as discovered yesterday morning with NEAT's Mt. Palomar telescope in southern California, and confirmed last night and this morning by seven observatories in Europe and the U.S. Southwest.

JPL puts the diameter at 2.28 km. (1.42 miles), so it's just as well that there is only one low rated solution long away. And a sharp-eyed anonymous observer points out to A/CC that the JPL assessment is based on the 1.006-day observing arc in the announcement MPEC, but the Minor Planet Center Last Observation page is showing a 47-day arc, so new data appears to be available.