NASA Scientific and Technical Aerospace Reports

20040070922 NASA Marshall Space Flight Center, Huntsville, AL, USA
Crystallization of a Li2O2SiO2 Glass under High Hydrostatic Pressures
Fuss, T.; Day, D. E.; Lesher, C. E.; Ray, C. S.; [2004]; 1 pp.; In English; 106th Annual Meeting of the American Ceramic
Society, 18-21 Apr. 2004, Indianapolis, IN, USA
Contract(s)/Grant(s): NAG8-1465; No Copyright; Avail: Other Sources; Abstract Only
The crystallization behavior of a Li2O.2SiO2 (LS2) glass subjected to a uniform hydrostatic pressure of 4.5 or 6 GPa was
investigated between 550 and 800 C using XRD, IR, Raman, TEM, NMR, and DTA. The density of the glass subjected to 6
GPa was between 2.52 plus or minus 0.01 and 2.57 plus or minus 0.01 grams per cubic centimeters, depending upon the
processing temperatures, and was higher than that of the stoichiometric LS2 crystals, 2.46 plus or minus 0.01 grams per cubic
centimeter. Thus, crystallization in 6 GPa glass occurred in a condition of negative volume dilatation, deltaV = V(sub glass)
- V(sub crystal), while that for the 4.5 GPa glass occurred in the condition deltaV greater than 0. For deltaV greater than 0,
which also includes the control glass at ambient (one atmosphere) pressure, the glasses always crystallize Li2Si2O5
(orthorhombic, Ccc2) crystals, but for deltaV less than 0 (6 GPa), the glasses crystallize Li2SiO3 crystals with a slightly
deformed structure. The crystal growth rate vs. temperature curve moved to higher temperature with increasing pressure, and
was independent of the sign of deltaV. These results for the effect of hydrostatic pressure on the crystallization of LS2 glass
were discussed from thermodynamic considerations.
Author
Crystallization; Hydrostatic Pressure; Lithium Compounds; Silicon Dioxide; Glass; High Pressure
20040070958 Planetary Science Inst., Tucson, AZ, USA
Observing the Sky and Lunar Photo of the Day: Two New Astronomy Education Web Sites
Wood, C. A.; Brausch, J.; Kramer, R.; Ayiomamitis, A.; Lunar and Planetary Science XXXV: Engaging K-12 Educators,
Students and the General Public in Space Science Exploration; 2004; 1 pp.; In English; Lunar and Planetary Science XXXV,
15-19 Mar. 2004, Houston, TX, USA; No Copyright; Avail: CASI; C01, CD-ROM; A01, Hardcopy
The Internet provides the most direct way for scientists to communicate with large numbers of people around the world,
without the distortions often introduced by traditional media. Thus, the Internet is the ideal medium for large-scale scientific
public outreach. Having previously reached as many as 4,000,000 unique visitors per year with VolcanoWorld (http://
volcano.und.edu), a NASA-funded web site that provided information direct from PhD volcanologists, we have developed two
new astronomy-related web sites to provide accurate and interesting information to teachers, students and the public.
Derived from text
Education; Websites; Lunar Photographs; NASA Space Programs; Astronomy; Volcanology
20040071004 Agnes Scott Coll., Decatur, GA, USA
Public Enthusiasm Generated by the 2003 Mars Opposition and Landing of the Exploration Rovers
Crane, A. N.; Albin, E. F.; Lunar and Planetary Science XXXV: Engaging K-12 Educators, Students and the General Public
in Space Science Exploration; 2004; 1 pp.; In English; Lunar and Planetary Science XXXV, 15-19 Mar. 2004, Houston, TX,
USA; Copyright; Avail: CASI; C01, CD-ROM; A01, Hardcopy
Interest in Mars is at an all time high. For many weeks leading up to and after August 27th or, the date of opposition,
record crowds flocked to observatories for a look at Mars. Public enthusiasm was just as high upon the landing on the two
exploration rovers in January 2004. Even after the media "dropped" the event and moved on to other stories, the
public response was still strong. It is suggested that such overwhelming public enthusiasm can be taken as good reason to seek
a higher level of government funding for the exploration of the Red Planet. Observations and impressions of the public
response to the 2003 close approach and exploration rover landings on Mars were taken from our affiliation with the Fernbank
Science Center in Atlanta, Georgia -- a museum which houses a well equipped planetarium and observatory. Fernbank staff
produced an original planetarium presentation entitled "Visions of Mars." Due to overflow crowds, special
extended showings were offered. After the planetarium program, members of the public were invited to the observatory for
a look at Mars. On many evenings, centered around opposition, the observatory remained open from 9:00 p.m. until 5:30 a.m.
the following morning. On each of these nights, we estimate that at least 950 people saw Mars through our telescope. An
important tool, the CCD video camera, proved invaluable in preparing observers for their actual observation of Mars. The
Mars mania continues. Two Mars Exploration Rovers were launched toward the Red Planet in the summer of 2003. These
probes, Spirit and Opportunity, landed on Mars in January 2004 .
Derived from text
Mars Exploration; Mars Roving Vehicles; Mars Landing
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