Letters from the May 7, 2005, issue of Science News

Clearer yet

“Weighing In on a Star: A stellar size limit” (SN: 3/12/05, p. 164) includes three images of the Arches cluster near the center of the Milky Way, each taken with a different telescope. I’d be interested to know what the three telescopes are.

John McKee
Brunswick, Maine

In the trio of progressively sharper (left to right) images, the leftmost one was taken in 1994 with a 3-meter telescope at the Lick Observatory in California, the middle image was taken in 1996 by the 10-m Keck 1 telescope atop Hawaii’s Mauna Kea, and the rightmost picture was taken in 1997 by the Hubble Space Telescope’s Near Infrared Camera and Multi-Object Spectrometer.—R. Cowen

Lifeless discussion

The many reports of the explorations of Mars looking for water (“Martian Landscaping: Spacecraft eyes evidence of a frozen sea,” SN: 3/5/05, p. 149) seem to be motivated by mere curiosity. Even if water is found on Mars, the lack of a Martian magnetic field would expose any life on Mars to the ravages of radiation from space. The high-velocity sandstorms would also be adverse to any life on Mars. In light of these facts, it seems that the current explorations of Mars lack direction and purpose.

Mark Bach
Gurnee, Ill.

Old news but bad news

You may be aware that nanoparticles from sources such as diesel engines have clearly been shown to be a major component of the exposures causing thousands of human deaths in the London smog of 1952. So, the news regarding synthetic nanoscale particles (“Nano Hazards: Exposure to minute particles harms lungs, circulatory system,” SN: 3/19/05, p. 179) is important but not terribly surprising.

Jerrold L. Abraham
SUNY Upstate Medical University
Syracuse, N.Y.

Cause or effect?

I am troubled by the conclusion drawn in “College may endow memory to old brains” (SN: 3/26/05, p. 205). The report says that college-educated adults do better on memory tests, displaying pronounced frontal brain activity, than do their less-educated peers. Might it not be just as reasonable to hypothesize that those who are able to “recruit the frontal brain into a memory system” do better in school and are, therefore, more likely to extend their educations?

Kathryn Klein
Redwood City, Calif.