[meteorite-list]

From: Pat <bigredwizard_at_meteoritecentral.com>
Date: Wed Aug 10 21:54:49 2005
Message-ID: <007001c59e17$abc1ac00$0300a8c0_at_tim>

----- Original Message -----
From: "Pat" <bigredwizard_at_earthlink.net>
To: "Meteorite Mailing List" <meteorite-list_at_meteoritecentral.com>
Sent: Wednesday, August 10, 2005 4:15 PM
Subject: [meteorite-list] test


> test
>
> ----- Original Message -----
> From: "Ron Baalke" <baalke_at_zagami.jpl.nasa.gov>
> To: "Meteorite Mailing List" <meteorite-list_at_meteoritecentral.com>
> Sent: Wednesday, August 10, 2005 4:09 PM
> Subject: [meteorite-list] VLT NACO Instrument Helps Discover First
> TripleAsteroid
>
>
>>
>> http://www.eso.org/outreach/press-rel/pr-2005/pr-21-05.html
>>
>> ESO Press Release 21/05
>> 11 August 2005
>>
>> Under Embargo until August 10, 2005 at 19:00 CET (17:00 GMT)
>> Rubble-Pile Minor Planet Sylvia and Her Twins
>>
>> VLT NACO Instrument Helps Discover First Triple Asteroid
>>
>> One of the thousands of minor planets orbiting the Sun has been found to
>> have its own mini planetary system. Astronomer Franck Marchis
>> (University of California, Berkeley, USA)
>> and his colleagues at the Observatoire de Paris
>> (France) [1] have discovered the first triple asteroid system -
>> two small asteroids orbiting a larger one known since 1866 as 87 Sylvia
>> [2].
>>
>> "Since double asteroids seem to be common, people have been looking for
>> multiple asteroid systems for a long time," said Marchis. "I couldn't
>> believe we found one."
>>
>> The discovery was made with Yepun, one of ESO's 8.2-m telescopes of the
>> Very Large Telescope Array at Cerro Paranal (Chile), using the
>> outstanding image' sharpness provided by the adaptive optics NACO
>> instrument. Via the observatory's proven "Service Observing Mode",
>> Marchis and his colleagues were able to obtain sky images of many
>> asteroids over a six-month period without actually having to travel to
>> Chile.
>>
>> ESO PR Photo 25a/05 <images/phot-25a-05-preview.jpg>
>>
>> ESO PR Photo 25a/05
>>
>> Orbits of Twin Moonlets around 87 Sylvia
>>
>> [Preview - JPEG: 400 x 516 pix - 145k] <images/phot-25a-05-preview.jpg>
>> [Normal - JPEG: 800 x 1032 pix - 350k] <images/phot-25a-05-normal.jpg>
>>
>> ESO PR Photo 25b/05 <images/phot-25b-05-preview.jpg>
>>
>> ESO PR Photo 25b/05
>>
>> Artist's impression of the triple asteroid system
>>
>> [Preview - JPEG: 420 x 400 pix - 98k] <images/phot-25b-05-preview.jpg>
>> [Normal - JPEG: 849 x 800 pix - 238k] <images/phot-25b-05-normal.jpg>
>> [Full Res - JPEG: 4000 x 3407 pix - 3.7M]
>> <images/phot-25b-05-fullres.jpg>
>> [Full Res - TIFF: 4000 x 3000 pix - 36.0M]
>> <images/phot-25b-05-fullres.tif>
>>
>> Caption: ESO PR Photo 25a/05 is a composite image showing the positions
>> of Remus and Romulus around 87 Sylvia on 9 different nights as seen on
>> NACO images. It clearly reveals the orbits of the two moonlets. The
>> inset shows the potato shape of 87 Sylvia. The field of view is 2
>> arcsec. North is up and East is left. ESO PR Photo 25b/05 is an artist
>> rendering of the triple system: Romulus, Sylvia, and Remus.
>>
>> ESO Video Clip 03/05 <video/vid-03-05.mov>
>>
>> ESO Video Clip 03/05
>>
>> Asteroid Sylvia and Her Twins
>>
>> [Quicktime Movie - 50 sec - 384 x 288 pix - 12.6M] <video/vid-03-05.mov>
>>
>> Caption: ESO PR Video Clip 03/05 is an artist rendering of the triple
>> asteroid system showing the large asteroid 87 Sylvia spinning at a rapid
>> rate and surrounded by two smaller asteroids (Remus and Romulus) in
>> orbit around it. This computer animation is also available in broadcast
>> quality to the media (please contact Herbert Zodet
>> <../../epr/epr-contact.html>).
>>
>>
>> One of these asteroids was 87 Sylvia, which was known to be double since
>> 2001, from observations made by Mike Brown and Jean-Luc Margot with the
>> Keck telescope. The astronomers used NACO to observe Sylvia on 27
>> occasions, over a two-month period. On each of the images, the known
>> small companion was seen, allowing Marchis and his colleagues to
>> precisely
>> compute its orbit. But on 12 of the images, the astronomers also found a
>> closer and
>> smaller companion. 87 Sylvia is thus not double but triple!
>>
>> Because 87 Sylvia was named after Rhea Sylvia, the mythical mother of
>> the founders of Rome [3], Marchis proposed naming the twin
>> moons after those founders: Romulus and Remus. The International
>> Astronomical Union <http://www.iau.org/> approved the names.
>>
>> Sylvia's moons are considerably smaller, orbiting in nearly circular
>> orbits and in the same plane and direction. The closest and newly
>> discovered moonlet, orbiting about 710 km from Sylvia, is Remus, a body
>> only 7 km across and circling Sylvia every 33 hours. The second,
>> Romulus, orbits at about 1360 km in 87.6 hours and measures about 18 km
>> across.
>>
>> The asteroid 87 Sylvia is one of the largest known from the asteroid
>> main belt, and is located about 3.5 times further away from the Sun than
>> the Earth, between the orbits of Mars and Jupiter. The wealth of details
>> provided by the NACO images show that 87 Sylvia is shaped like a lumpy
>> potato, measuring 380 x 260 x 230 km (see ESO PR Photo 25a/05). It is
>> spinning at a rapid rate, once every 5 hours and 11 minutes.
>>
>> The observations of the moonlets' orbits allow the astronomers to
>> precisely calculate the mass and density of Sylvia. With a density only
>> 20% higher than the density of water, it is likely composed of water ice
>> and rubble from a primordial asteroid. "It could be up to 60 percent
>> empty space," said co-discoverer Daniel Hestroffer (Observatoire de
>> Paris, France).
>>
>> "It is most probably a "rubble-pile" asteroid", Marchis added. These
>> asteroids are loose aggregations of rock, presumably the result of a
>> collision. Two asteroids smacked into each other and got disrupted. The
>> new rubble-pile asteroid formed later by accumulation of large fragments
>> while the moonlets are probably debris left over from the collision that
>> were captured by the newly formed asteroid and eventually settled into
>> orbits around it. "Because of the way they form, we expect to see more
>> multiple asteroid systems like this."
>>
>> Marchis and his colleagues will report their discovery in the August 11
>> issue of the journal Nature, simultaneously with an announcement that
>> day at the Asteroid Comet Meteor conference in Arma??o dos B?zios, Rio
>> de Janeiro state, Brazil.
>>
>> Notes
>>
>> [1]: The team is composed of Franck Marchis (University of California,
>> Berkeley, USA) and Pascal Descamps, Daniel Hestroffer, and Jerome
>> Berthier (Observatoire de Paris, France).
>>
>> [2]: 87 Sylvia is the 87th minor planet discovered. It was first
>> observed from the Observatory of Madras (India) on May 16, 1866, by the
>> Government Astronomer Norman R. Pogson. It was common in the early days
>> to assign a name - mostly feminine - from the mythology to newly found
>> asteroids. Pogson selected a name from the list furnished to him by Sir
>> John Herschel.
>>
>> [3]: In the Appendix <pr-21-05_p2.html>, you can read the story of Syvia
>> and her sons, Romulus and Remus.
>>
>> The press release of the University of California, Berkeley, is
>> available here
>> <http://www.berkeley.edu/news/media/releases/2005/08/10_sylvia.shtml>
>> and the one from the Observatoire de Paris, here
>> <http://www.obspm.fr/actual/nouvelle/aug05/sylvia.en.shtml>.
>>
>> Contacts
>>
>> Franck Marchis
>> University of California, Berkeley, USA
>> Phone: +1 (510) 642 3958 or +1 (510) 599 0604
>> Email: fmarchis_at_berkeley.edu
>>
>> Pascal Descamps, Daniel Hestroffer, Jerome Berthier
>> IMCCE, Observatoire de Paris, France
>> Phone: +33 1 4051 2268 or +33 1 4051 2260
>> Email: descamps_at_imcce.fr, hestroffer@imcce.fr, berthier@imcce.fr
>>
>>
>> National contacts for the media:
>>
>> Belgium - Dr. Rodrigo Alvarez +32-2-474 70 50 rodrigo.alvarez_at_oma.be
>> Finland - Ms. Terhi Loukiainen +358 9 7748 8385 terhi.loukiainen_at_aka.fi
>> Denmark - Dr. Michael Linden-V?rnle +45-33-18 19 97 mykal_at_tycho.dk
>> France - Dr. Daniel Kunth +33-1-44 32 80 85 kunth_at_iap.fr
>> Germany - Dr. Jakob Staude +49-6221-528229 staude_at_mpia.de
>> Italy - Prof. Massimo Capaccioli +39-081-55 75 511 capaccioli_at_na.astro.it
>> The Netherlands - Ms. Marieke Baan +31-20-525 74 80 mbaan_at_science.uva.nl
>> Portugal - Prof. Teresa Lago +351-22-089 833 mtlago_at_astro.up.pt
>> Sweden - Dr. Jesper Sollerman +46-8-55 37 85 54 jesper_at_astro.su.se
>> Switzerland - Dr. Martin Steinacher +41-31-324 23 82
>> martin.steinacher_at_sbf.admin.ch
>> United Kingdom - Mr. Peter Barratt +44-1793-44 20 25
>> Peter.Barratt_at_pparc.ac.uk
>>
>>
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Received on Wed 10 Aug 2005 09:54:54 PM PDT