A recent Department of Defense analysis of images of the Red Planet may have located a lost spacecraft on Mars, but NASA says the images could just be electronic noise. (p. 232)

Far beyond the solar system's nine known planets, a body as massive as Mars may once have been part of our planetary system, and it might still be there. (p. 213)

Ultrafast laser pulses may have for the first time revealed the incredibly rapid, step-by-step progress of a complete chemical reaction on a surface, at the actual speed at which it took place. (p. 221)

By detecting vibrations of less than an atom's width of a tiny cantilever, physicists have made the most sensitive measurement of force ever by mechanical means. (p. 221)

Although it's now the fifth element to be made into the strange state of ultracold matter known as Bose-Einstein condensate, helium may prove to be the most revealing so far because of unusually high energies within the newly condensed atoms. (p. 183)

Under the right circumstances, heating a tiny cluster of sodium atoms makes its temperature fall. (p. 143)

New observations that subatomic particles called B mesons decay differently from their antimatter versions may help explain why the universe is made almost entirely of matter, not antimatter. (p. 143)

Scientists have found another indicator that the sun has reached the maximum of its current activity cycle: The polarity of its magnetic field has reversed. (p. 139)