It's been a productive year for science and technology. Researchers have sequenced key genomes, discovered an entirely new order of insect and probed the outer reaches of the solar system with surprising results, to name but a few advances. Of course, 2002 also had its low points, perhaps most notably two prominent cases of fraud in physics. But in all, the progress outweighs the setbacks. From the hundreds of stories that ScientificAmerican.com has featured over the past year, we have selected the 25 that most impressed us--some with their importance, others simply with their gee-whiz appeal. We hope you enjoy these highlights, which appear in no particular order below. --The Editors

Controlling Robots with the Mind

People with nerve or limb injuries may one day be able to command wheelchairs, prosthetics and even paralyzed arms and legs by "thinking them through" the motions.

Scientists Sequence Genomes of Malarial Parasite and Mosquito

Malaria continues to plague the world's population, particularly inhabitants of sub-Saharan Africa, where it kills at least one person every 30 seconds. Efforts to eradicate the disease in the 1950s and 1960s met with failure, and current control measures such as antimalarial drugs are swiftly losing their potency. Now researchers have sequenced the genetic codes of the most deadly malarial parasite and a mosquito that carries it.

Cosmic Microwave Background Radiation's Polarization Detected at Last

Although it was discovered less than 40 years ago, the cosmic microwave background (CMB) radiation has been around a lot longer than that. A relic from the early days of the Universe more than 14 billion years ago, the CMB is the oldest radiation on record. Current cosmological models posit that the CMB should be slightly polarized but this property has never been observed--until now.

Mouse Genome Sequenced

In the name of science, researchers have fashioned numerous kinds of mice: fat, thin, hairless, or afflicted with a particular disease, to name a few. The first draft sequence of the mouse genome should make the tiny rodents even more helpful for future research into a variety of diseases.

Astronomers Discover Icy World Far Past Pluto

Astronomers have discovered the largest object in the solar system since Pluto was identified more than 70 years ago. The object, dubbed Quaoar (pronounced "kwa-whar") by its discoverers, is approximately half Pluto's size and nearly four billion miles away from Earth.

Stamp-Size Plastic Chip Provides New Approach to Cryptography

Modern encryption techniques are tested every time someone makes a purchase over the Internet or spends electronic cash stored in smart cards. These strategies rely on so-called one-way functions, which are easy to execute in one direction (for instance, multiplying two prime numbers) but difficult to reverse (factoring a large number into two primes). With ever-increasing computer power and advances in quantum computing, however, such methods may soon become breakable. Researchers have developed a new approach to cryptography--built around a piece of plastic the size of a stamp--that is hard to crack and nearly impossible to forge.

Meet the Oldest Member of the Human Family

After more than a decade of digging, researchers working in Chad have made the fossil discovery of a lifetime: a nearly complete skull said to belong to the oldest and most primitive member of the human family yet known. Nicknamed Touma¿¿or "hope of life" in the local Goran language¿it belongs to an entirely new genus and species of hominid, Sahelanthropus tchadensis. And at almost seven million years old, it has taken scientists several crucial steps closer to the point in time at which humans and chimpanzees diverged. Yet as is the case for most spectacular finds, this one raises as many questions, if not more, than it answers.