It is difficult to accept as new information Alfred McEwen's assertion that the Elysium Basin of Mars was formed by lava ("Lava may have sculpted Martian plains," SN: 11/7/98, p. 295). Low-resolution images of Elysium from Viking identified lava flows there in the early 1990s (Icarus 88, 465-490; USGS Map I-2397).

Mary Chapman
U.S. Geological Survey
Flagstaff, Ariz.

The Elysium Basin region was indeed described as entirely covered by young flood lavas in the 1990 Icarus paper by Jeff Plescia. However, most workers favored different interpretations, such as lake sediments on top of eroded lava (USGS Map I-2397). The new high-resolution images have dramatically confirmed Plescia's views.

Alfred S. McEwen
University of Arizona
Tucson, Ariz.

I disagree with part of McEwen's idea that the albedo markings represent plates of the lava flow that moved independently. I do agree that the material is almost certainly hundreds of meters thick, but I doubt it would have been liquid or that the entire region would have been active at the same time. For the features observed to be plates would require an exceedingly large (even by Martian standards) volume of lava to be liquid.

Additionally, it is unclear how sufficient material could have been erupted in the short time necessary. I had estimated that even with values such as occur in the Columbia Plateau, the time necessary would be too long to keep it all liquid to allow for the kind of conditions that McEwen is suggesting.

A simpler explanation is that these features are either dunes of windblown material or low areas filled in by windblown material.

Jeff Plescia
U.S. Geological Survey
Flagstaff, Ariz.

In "Democratizing Science" (SN: 11/7/98, p. 298), Mr. Daryl Chubin of the National Science Foundation thinks a university should assess how it serves its local community and should, at minimum, consider making staff available to the public. I thought a university's mission is to educate students, including any qualifying local students. I know there are many complaints about staff already being distant from actual students; the more "available" the staff is outside the university, the less available it is for the primary function.

I also wonder how accurately the Center for Neighborhood Technology "can predict how much money a household in any half-square-mile zone will spend on transportation."

Steve Sells
Wichita, Kan.