Top Thirty Publications
The following list are papers that I am most proud of, either because they represent pieces of work I think have proved of long term value, or I consider them particularly original, or because they were just fun to research or write.  Electronic copies are available by clicking on the publication number.

Number in Publication List


My reasons for including paper in list


Sears, D.W. and Mills, A.A. (1973)  Temperature gradients and atmospheric ablation rates for the Barwell meteorite.  Nature Physical Science, 242, 25-26.

The first publication, and Alan showed me how.  A neat application of quantitative theory to something normally considered purely descriptively.  I am not sure anyone cared, but 30 years later I was thinking about Earth Return Vehicles for sample return missions and this paper was of great value to me.


Sears. D.W. and Axon, H.J. (1976)  Nickel and cobalt contents of chondritic meteorites.  Nature, 260, 34-35.

I was trying to find something to do with magnetic residues from my PhD work and identified a new parameter to explore chondrite meteorites that has been used by many groups, the Co content of the kamacite.


Sears, D.W. (1980)  Thermoluminescence of meteorites; relationships with their K-Ar age and their shock and reheating history.  Icarus, 44, 190-206.

Some Russian researchers had previously argued that since K-Ar age correlated with TL sensitivity, TL was created by radiation damage.  I showed that, in fact, this was not the case but the high TL sensitivity of crystalline rocks was being lowered by shock, which also caused a loss of Ar.  I like this paper because it is well done and comes to an unexpected but very solid conclusion.


Sears, D.W., Grossman, J.N., Melcher, C.L., Ross, L.M. and Mills, A.A. (1980)  Measuring the metamorphic history of unequilibrated ordinary chondrites.  Nature, 287, 791-795.

This is my first well-known and well-cited paper, establishing a sequence and a classification scheme for primitive meteorites that is still in common use after nearly 30 years.  John Wasson played a crucial role, encouraging us to make the measurements and providing the samples.


Guimon, R.K., Weeks, K.S., Keck, B.D. and Sears, D.W.G. (1984)  Thermoluminescence as a palaeothermometer.  Nature, 311, 363-365.

A novel and largely unanticipated result, that the shape of the TL glow curve also reflects thermal history, not just the level of induced TL.  This paper reminds me of the importance of enthusiastic graduate students who are not deterred from making measurements that some said could not be done.  I learned a lot from Kyle, who died in early 2006.


Hartmetz, C.P., Ostertag, R. and Sears, D.W.G. (1986)  A thermoluminescence study of experimentally shock-loaded oligoclase and bytownite. Proc. 17th Lunar and Planet. Sci. Conf., Part 1, J. Geophys. Res., 91, E263-E274.

Work on terrestrial minerals sometimes helps us understand extraterrestrial materials.  This work showed that the shape of the TL glow curve is related to the degree of disorder in the feldspar crystals and thus explains why the shape of the TL glow curve can be related to thermal history.


Hasan, F.A., Haq, M. and Sears, D.W.G. (1987)  Natural thermoluminescence levels in meteorites, I:  23 meteorites of known Al-26 content.  Proc. 17th Lunar and Planet. Sci. Conf., Part 2, J. Geophys. Res., 92, E703-E709.

This paper was fun because it was done at the instigation of a committee trying to increase the utility of Antarctic meteorites.  Sure enough, we found that natural TL could identify meteorites that were petrographically familiar but had interesting physical histories. As a result of this paper, NASA and NSF established the natural TL Survey of Antarctic meteorites.  Robert Walker and Steve Sutton played an important advocacy role in this effort.


Batchelor, J.D. and Sears, D.W.G. (1991)  Metamorphism of eucrite meteorites studied quantitatively using thermoluminescence.  Nature 349, 516-519.

We showed that the TL technique worked not just with primitive chondrites but also with these meteorites that were formed as lavas during some sort of volcanism.


Benoit, P.H., Sears, D.W.G. and McKeever, S.W.S. (1991)  The natural thermoluminescence of meteorites - II. Meteorite orbits and orbital evolution. Icarus 94, 311-325.

Early work by physicists suggested that natural TL levels would reflect perihelion distance, and we pursued this idea, successfully.


Benoit P.H. and Sears D.W.G. (1992) The breakup of a meteorite parent body and the delivery of meteorites to Earth.  Science 255, 1685-1687.

The boldness of this work pleases me.  Meteorites that were all part of an asteroid that fragmented by a single event 8 Ma ago - but arrived on earth 40,000 years apart - have different metamorphic history.  Orbital streaming means that meteorites that released from different places on the asteroid arrive on Earth at different times.  We made it into the New York Times!


Benoit P.H., Jull A.J.T., Mckeever S.W.S. and Sears D.W.G. (1993)  The natural thermoluminescence of meteorites VI:  Carbon-14, thermoluminescence and the terrestrial ages of meteorites.  Meteoritics 28, 196-203.

This paper pleases me because it is one big "I told you so"!  When our natural TL data were first published, people cynical of TL pointed out their poor agreement with 14C data.  Twenty years later radiocarbon data improved because of the invention of accelerator mass spectrometry and the correlation was vastly improved.


Benoit P.H., Sears D.W.G. and McKeever S.W.S. (1993)  Natural thermoluminescence and terrestrial ages of meteorites  from a variety of temperature regimes.  Radiat. Detect. Dosimet. 47, 699-674.

This was a hurriedly-written but never-the-less very nice paper showing how natural TL can be used in a variety of climates to determine terrestrial age, adjusting the theoretical curves for local temperatures.


Matsunami S., Ninagawa K., Nishimura S., Kubon N., Yamamoto I., Kohata M., Wada T., Yamashita Y., Lu Jie, Sears D. W. G., and Nishimura H. (1993)  Thermoluminescence and compositional zoning in the mesostasis of a Semarkona group A1 chondrules and new insights into the chondrule-forming process.  Geochim. Cosmochim. Acta 57, 2101-2110.

Here we tackled a dogma of 20 years - that chondrules were closed systems during their formation - with unique new observations and careful reasoning.  We were successful in overturning the dogma.


Sears D.W.G., Benoit P.H. and Lu Jie (1993)  Two groups each with distinctive rims in Murchison recognized by cathodoluminescence.  Meteoritics 28, 669-675.

A new type of observation (cathodo-luminescence) showed rather clearly that the famous rims on chondrules depended on what was being rimmed, and therefore that rims are condensates from evaporation that occurred during chondrule formation.


Benoit P.H. and Sears D.W.G. (1994)  A recent meteorite fall in Antarctic with an unusual orbital history.  Earth Planet. Sci. Lett. 120, 463-471.

A technique has come of age when it makes discoveries that were not predicted.  While we were looking at terrestrial ages and searching for meteorites that had been close to the Sun, we discovered a meteorite that had only recently - in geological terms - become Earth-crossing.


Sears D.W.G., Huang S. and Benoit P.H. (1995)  Chondrule formation, metamorphism, brecciation, an important new primary chond-rule group, and the classification of chondrules.  Earth Planet. Sci. Lett. 131, 27-39.

Two groups of chondrules (lithic and droplet) have been known for a century under various names, neither with “chondritic” phase compositions.  We found a third type, which have chondritic compositions while being essentially unequilibrated.


Sears D.W.G., Symes S.P., Guimon R.K. and Benoit P.H. (1995)  Chemical and physical studies of type 3 chondrites XII:  The metamorphic history of CV chondrites and their components.  Meteoritics 30, 707-714.

We even found that the refractory inclusions in Allende - famous for being the oldest materials in the solar system - also form a metamorphic sequence that can be identified from their induced TL properties.


Yanghong Zhang, Benoit P.H. and Sears D.W.G. (1995)  The classification and thermal history of enstatite chondrites.  Jour. Geophys. Res. - Planets 100, 9417-9438.

Ms. Zhang was my guide on a visit to China and I was fascinated by her.  She later came to the US as my student and did some neat work in the enstatite chondrites.  Here we stressed the major differences in thermal history of the EL and EH classes which were previsouly thought be a single genetic series..


Huang Shaoxiong and Sears D. W. G. (1996)  Metal-silicate fractionation in the surface dust layers of accreting planetesimals:  Implications for the formation of chondrites and the nature of asteroid surfaces.  J. Geophys. Res. - Planets 101, 29,373 - 29,385.

A brave new suggestion that the chondrite classes - marked for their differing amounts of metal relative to silicates - were caused by the way metal and silicate became separated on the surface of an asteroid.


Sears D.W.G., Huang S. and Benoit P.H. (1996)  Open-system behavior during chondrule formation.  In "Chondrules and the Protoplanetary Disk", (eds. Hewins, R., Jones R. H. and Scott E. R. D.), pp. 221-231.  Cambridge University Press.

This was my major paper establishing the open system nature of chondrule formation - which has implications for explaining the meteorite classes - and since this paper was published the conclusion has hardly been challenged.


Yanghong Zhang, Benoit P.H. and Sears D.W.G. (1996)  Pyroxene structures, cathodoluminescence and the thermal history of the enstatite chondrites.  Meteorit. Planet. Sci. 31, 87-96.

Here we pursued an idea briefly mentioned in the literature previously that the structure of pyroxenes determines their cathodoluminescence properties, and this was a reflection of differences between the classes in thermal history.


Akridge D. G. and Sears D. W. G. (1998)  Regolith and megaregolith formation of H-chondrites:  Thermal constraints on the parent body. Icarus 132, 185-195.

Glen performed these thermal calculations that showed that chondrite meteorites could all come from the surface layers of an asteroid.


Sears D. W. G. (1998)  The rarity of chondrules and CAI in  the early solar system and some astrophysical consequences.  Astrophys. Jour. 498, 773-778

Another attempt to tackle dogmas, and I think it was at least partially successful - why assume chondrules are common because they are common in a major class of the fallen meteorites.  All the evidence is that they are actually rare, as rare as refractory inclusions called CAI.


Sears D. W. G. and Kral T. A. (1998)  Martian "microfossils" in lunar meteorites?  Meteorit. Planet. Sci.  33, 791-794.

Sometimes politics overwhelms science, such as when some JSC researchers found "fossils" in a martian meteorite.  The JSC-NASA-media circus over this issue involved sex, violence, power, and money – I am waiting for the movie – in which our small paper was a plea for sanity.  Nonsense, we said, there are similar structures in meteorites from barren planets.  A lot of people agreed with us, but said nothing, waiting for the dollars.


Symes S. J. K., Sears D. W. G., Taunton A., Akridge D. G., Yanghong Zhang and Benoit P. H. (1998)  The crystalline lunar spherules:  Their formation and implications for the origin of meteoritic chondrules.  Meteorit. Planet. Sci. 33, 13-29.

I was surprised to learn that this is one of my most cited papers.  It makes the case that chondrules - whose origin has long been unclear - are simply the impact melt spherules from the surfaces of asteroids.  This was a very controversial conclusion, but has met with a surprisingly positive response.


Akridge D. G. and Sears D. W. G. (1999)  The gravitational and aerodynamic sorting of meteoritic chondrules and metal:  Experimental results with implications for chondritic meteorites.  J. Geophys. Res. (Planets) 104, 11853-11864.

A very sound and very original attempt to understand chondritic meteorites in terms of processes likely to be occurring on the surface of an asteroid


Sears D. W. G., Kochan H. and Huebner W. F. (1999)  Simulation experiments and surface processes on comets.  Meteorit. Planet. Sci. 34, 497-525.

My first excursion into comets and laboratory space simulations and brought me into contact with two new friends, Walter Huebner and Herman Kochan


Sears, D. W. G.; Allen, C. C.; Britt, D. T.; Brownlee, D. E.; Cheng, A. F.; Chapman, C. R.; Clark, B. C.; Drake, B. G.; Fevig, R. A.; Franchi, I. A.; Fujiwara, A.; Gorevan, S. P.; Kochan, H.; Lewis, J. S.; Lindstrom, M. M.; Nishiizumi, K.; Race, M. S.; Scheeres, D. J.; Scott, E. R. D.; Taylor, G. J.; Yano, H. (2002)  Near-Earth Asteroid Sample Return.  In The Future of Solar System Exploration (2003-2013) -- Community Contributions to the NRC Solar System Exploration Decadal Survey. ASP Conference Proceedings, Vol. 272. Edited by Mark V. Sykes. San Francisco, Astronomical Society of the Pacific, 2002, pp. 111-140.

An important step in my efforts to persuade the scientific community and NASA that we will never be able to fully understand primitive materials of the solar system without bringing back samples from known locations on a known asteroid. This article was apparently successful because near-Earth asteroid sample return featured prominently in the final National Academies report.


Akridge, D. G.; Akridge, J. M. C.; Batchelor, J. D.; Benoit, P. H.; Brewer, J.; DeHart, J. M.; Keck, B. D.; Jie, Lu; Meier, A.; Penrose, M.; Schneider, D. M.; Sears, D. W. G.; Symes, S. J. K.; Yanhong, Zhang (2004)  Photomosaics of the cathodoluminescence of 60 sections of meteorites and lunar samples.  Journal of Geophysical Research, Volume 109, Issue E7, CiteID E07S0

Summarizes the work of virtually all my students to that date and represents a unique and widely unappreciated view of meteorites, the view from cathodoluminescence which captures both petrologic and compositional information


Sears, Derek W. G.; Moore, Shauntae R. (2005)  On laboratory simulation and the evaporation rate of water on Mars.  Geophysical Research Letters, Volume 32, Issue 16, CiteID L16202

An entirely new research area for us.  Groups at Caltech and Berkeley tried to make these measurements, but our results are by far the best for precision and accuracy.  The paper is a testimony to an incredible student.


Sears, Derek W. G.; Chittenden, Julie D. (2005)  On laboratory simulation and the temperature dependence of the evaporation rate of brine on Mars.  Geophysical Research Letters, Volume 32, Issue 23, CiteID L23203

And we could do the measurements at any temperature.  So what if the data simply confirmed theory, it is a weak theory it shows we have mastered the techniques.  While very different to Shauntae, Julie is also an incredible student.


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