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

Today's issue status: done, updated

• News briefs – new comet C/2004 C1 (Larsen), European weather site, dark skies, Rosetta news & spacecraft computers
• Risk monitoring
  Part 2 – JPL has removed 2004 BG121

Cover image: Photograph by Graziano Ventre and Enrico Colzani of a Leonid fireball at 3:15am local time on 17 November 1998 at Sormano Observatory in Italy. This two-minute exposure was made with a 35mm camera with 50mm lens at f/1.9 and Fujiicolor 800 SuperPlus film. See another photo from the same morning on the February 2nd cover.

Comet news:  MPEC 2004-C52 today announces C/2004 C1 (Larsen), discovered yesterday morning by Jeff Larsen with the Spacewatch 0.9m telescope in Arizona and confirmed this morning with three other telescopes in Arizona and one each in Kansas and southern California. The preliminary calculation has a 56.3°-inclined parabolic orbit with perihelion at a distant 4.263 AU on October 12th next year.

Weather site:  The European Space Agency announced yesterday its new Weather Today site with a Meteosat view of clouds over Europe.

Dark skies:  The Durango, Colorado Herald has an article from yesterday, "City officials hear comments on dark skies," telling about a proposed ordinance discussed at a public information meeting the night before, at which many common issues were raised. And the Alamogordo, New Mexico Daily News has an item today about "tightening the decade-old Dark Sky Ordinance" in Cloudcroft.

Rosetta:  The Rosetta Journal has now had four days of daily entries, from the 10th through today:

• Tuesday: "Lander successfully completes on-ground check-out" — "only a few protective covers and other 'remove-before-flight' items still have to be removed (including tip protectors of the harpoons)"
• Wednesday: "Ariane 5 Rolls Out" — from the Launcher Integration Building to the Final Integration Building, where Rosetta will be hoisted aboard
• Yesterday: "Rosetta integrated with ACU" (launch vehicle adapter)
• Today: "Power Supply Rack Installation" for Rosetta pre-launch power from the "launch table" on which the Ariane 5 sits and travels, and from which it will be launched

New Scientist has an article from yesterday, "Europe's comet-chasing mission passes final test":

“ [The] last of 25 [launch simulations] carried out since the mission was reconfigured . . . was completed on Wednesday without a hitch . . . involving centres in Europe, South America, the US, and Australia. ”

Spacecraft computers:  PC World has an interview today with a Wind River programmer about the computer on the Mars rovers and the Stardust and Spitzer spacecraft (more about spacecraft computers).

Risk monitoring 13 Feb.

One would think it was Friday the 13th the way things have been going with computers at the Minor Planet Center (MPC) and at the JPL NEO Program in recent days. The MPC reported various problems over the last three days with its Web services for observers and in preparing the Thursday Daily Orbit Update MPEC. Meanwhile, the JPL Sentry Web site, with its lists and data for objects with impact solutions, was down yesterday, taken off-line to thwart a hacker attack in an episode that began Wednesday morning, and there have been some technical difficulties which still have that site down today. This is also affecting the related JPL Solar System Dynamics (SSD) site with the Horizons ephemeris service.

The MPC hasn't reported any problems today, and A/CC has been informed that the JPL Sentry and SSD sites may be back up later today.

On Wednesday, the 11th, NEODyS joined JPL in posting 2004 BG121. The Wednesday Daily Orbit Update (DOU) MPEC had 2004 CB observations

from the 10th from Powell and Tenagra II observatories and LINEAR, and from Great Shefford Observatory early on the 11th. Both risk monitors that day lowered their overall risk estimates slightly for 2004 CB.

The Thursday DOU didn't have new observations for any objects that are listed with impact solutions and are currently in view, but NEODyS updated on 2004 BG121, noting one additional observation within the existing observing arc, and very slightly raising its BG121 risk ratings. The Friday DOU shows that

more Risk monitoring >>

<< continued from part 1

this observation came from Linz Observatory in Austria from the night of January 30th.

The Friday DOU also carries a set of observations of 2004 CB from the 11th from Robert Hutsebaut using a Rent-a-scope telescope at New Mexico Skies Observatory. However, Friday night in Pisa, NEODyS hasn't yet publicly updated its 2004 CB assessment.

2248 UTC update:  Noticed at 2:30pm in Pasadena is that the JPL NEO Program Sentry Web site is back up, but active risk assessments haven't been updated yet (see Current Impact Risks).

0052 UTC update:  JPL has removed 2004 BG121.

0210 UTC update:  JPL has updated its 2004 CB assessment, slightly lowering overall risk ratings. (NEODyS hasn't yet publicly updated its 2004 CB assessment with Friday's new data from the 11th.)