To argue that the concentrations reported in "Macho Moms: Perchlorate pollutant masculinizes fish" (SN: 8/12/06, p. 99) are environmentally relevant is misleading. Those concentrations are usually in groundwater, not surface waters. I've been involved in the environmental field for almost 20 years and have yet to hear of any fish being caught in groundwater.
Study coauthor Frank von Hippel notes that much of the nation's water supply comes from groundwater and says that "groundwater flows just like surface water and, in many places, becomes surface water."—J. Raloff
I was sorry to learn Pluto did not qualify as a planet ("New Solar System? Twelve planets and counting," SN: 8/19/06, p. 115, and "Doggone! Pluto gets a planetary demotion," SN: 9/2/06, p. 149). Pluto has a diameter comparable with the Earth's moon. The size of our moon relative to Earth might cause any observer to consider Earth and its moon as double planets. Pluto and Charon could have equal status.
Las Vegas, Nev.
Strictly speaking, the original five "wandering stars" (in the Copernican sense) are the only sun-orbiting bodies that can rightly be called planets. In changing the definition of planet, the International Astronomical Union is messing with something much bigger than it is. Think of all the dictionaries, encyclopedias, textbooks, and Web sites that will need revision as a result of IAU's action.
Virgil H. Soule
The detection of bodies orbiting other stars suggests that the criteria we use to apply the word planet is a matter of broad significance. The criteria accepted by IAU seem to work for our solar system but don't seem general enough to allow classification of all bodies we may detect.
Coral Gables, Fla.
Astronomers have duly decided that Pluto and others should be called "dwarf planets," but the greater problem is with the term for subordinate satellites. Galileo referred to Jupiter's subordinates as "moons." That is really wrong. There is one Moon. We need a term, such as subsat, for subordinate satellites.