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Recent Noteworthy Papers from Division Scientists
New Cover Story!
The Mid December volume of the journal Science is a special
issue devoted to the Stardust mission. The cover depicts
a piece of aerogel that flew to Comet Wild2 and tracks caused
by captured comet dust can be seen. Scott
Sandford is first author and George Cooper a co-author of
the report 'Organics
Captured from Comet 81P/Wild 2 by the Stardust Spacecraft'
Dr. Sandford is a co-author on the report 'Infrared
Spectroscopy of Comet 81P/Wild 2 Samples Returned by Stardust'
and both Drs. Sandford and Cooper are co-authors on the research
article 'Comet
81P/Wild 2 Under a Microscope'. All of the papers can be
downloaded as PDF files and the Introduction to special issue
'Look into the Seeds of Time' by Joanne Baker can be found by
following
this link.
Rain on Titan:
McKay article and press coverage Dr. Chris McKay is co-author
of the letter 'Methane drizzle on Titan' in the most recent issue
of the journal nature, which is discussed in an editors
summary, or you can read the full text online at http://www.nature.com/nature/journal/v442/n7101/full/nature04948.html
This article attracted
considerable (and international) press coverage including 'Searching
For Aliens' from Space Daily, 'NASA
Reports That Methane Drizzles on Saturn's Moon, Titan' from
Space Ref, and an interview
with Dr. McKay about searching for aliens appeared in Astrobiology
News online on July 27th.
A. G. G. M. Tielens is a co-author on a research article
that appeared recently in Science (14 July 2006: Vol. 313. no.
5784, pp. 196-200) entitled 'Massive-Star Supernovae as Major
Dust Factories' This article is available online via science
express at http://tinyurl.com/zgajm
Chondrule formation in particle-rich nebular regions at least
hundreds of kilometres across by Jeffrey
N. Cuzzi and Conel M. O'D. Alexander.
Chondrules are the dominant, enigmatic components of primitive
meteorites and probably of most primitive asteroids; they were
melted in the protoplanetary nebula and have thus lost some
of their more volatile elements (Mg, Si). Research by Space
Science Division Scientist Jeff
Cuzzi and collaborator Conel Alexander (DTM, Carnegie Institution)
suggests an explanation for a puzzling lack of the expected
preferential loss of light isotopes of these elements from chondrules.
The new model shows that if chondrule formation regions have
a certain chondrule density (roughly 10 per cubic meter) and
size (roughly 100-1000km), evaporating vapor clouds from each
chondrule overlap, replacing the lost light isotopes. The results
seem to preclude some candidate chondrule formation mechanisms
such as nebula lightning and bow shocks from numerous small
planetesimals, which act on smaller scales. The work appeared
in the May 25 issue of Nature. Click
here to be taken to the online version of the article at
nature.com and see the News
and Views piece by Steve Desch.
Other Cover Stories
An image of microbial mats taken by division scientist Lee Bebout
from their Baja Mexico Field site is the cover shot for the journal
Applied and Environmental Microbiology in association with the
article 'Unexpected Diversity and Complexity of the Guerrero Negro
Hypersaline Microbial Mat' co-authored by division scientist Brad
M. Bebout. For more information see http://aem.asm.org/cgi/content/short/72/5/3685
and http://aem.asm.org/content/vol72/issue5/cover.shtml
Two new moons, named Mab and Cupid, and two new outer rings
have been discovered around Uranus by former division scientist
Showalter and division scientist Lissauer (p. 973,
published online 22 December 2005; see the cover and the Perspective
by Murray).
These new members of the uranian system were spotted in images
from the Hubble Space Telescope and traced in earlier pictures
from Voyager 2. Substantial changes are seen in the passages
of the moons and brightness of the rings since the Voyager 2
fly-by. Many of Uranus' moons do not follow simple keplerian
orbits but exhibit complex dynamics, which suggest that the
whole system is gravitationally unstable or chaotic.
Other recent noteworthy papers:
Bernstein, M.
P.; Cruikshank, D. P.; Sandford, S. A. (2006) Near-infrared
laboratory spectra of CH4 in Solid H2O.
Icarus Volume 181, Issue 1, March 2006, Pages 302-30 Available
online.
Manning, Curtis V.; McKay, Christopher P.; Zahnle, Kevin J. (2006)
Thick and thin models of the evolution of carbon dioxide on Mars.
Icarus, Volume 180, Issue 1, p. 38-59. Available online.
Brown, Robert H.; Clark, Roger N.; Buratti, Bonnie J.; Cruikshank,
Dale P.; Barnes, Jason W.; Mastrapa,
Rachel M. E.; Bauer, J.; Newman, S.; Momary, T.; Baines, K.
H.; and 15 coauthors (2006) Composition and Physical Properties
of Enceladus' Surface Science, Volume 311, Issue 5766, pp. 1425-1428.
Available online.
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