The Best Science of 1994

1. Crash of the Century.

If you've gotta go, go with a bang. That's what Comet Shoemaker-Levy 9 did last July. Nearly two dozen mountain-size chunks of this fragmented interplanetary wanderer slammed into Jupiter, creating 2,000-mile-high fireballs and sooty smudges on the planet's cloud tops that were visible from backyard telescopes. Scientists learned much about Jupiter's atmosphere, about comets, and even about how a similar impact on earth might have killed off the dinosaurs. For most onlookers, though, it was just a fantastic show.

2. Gotcha!

Physicists think six types of quarks are the building blocks of all the particles within atomic nuclei. They had found the first five by 1977, and now the top quark, the sixth and heaviest, has been identified at Fermilab, near Chicago. It took 440 scientists to spot the top, which disintegrates in an infinitesimal fraction of a second.

3. Genetics Marches On

Breast cancer and severe obesity can both be deadly, and now there is evidence that both can result from faulty genes. Treatments are years away, but the discoveries are big steps toward that goal.

4. Bones from Way Back

Until this year the famed Lucy and her fellow members of the species Australopithecus afarensis were the oldest known members of the human family. No more: at 4.4 million years of age, the newly unearthed Australopithecus ramidus is the closest link yet (no longer missing) to the common ancestor of apes and humans. A second major find: Homo erectus, the first of Lucy's descendants to leave Africa, made that move about 800,000 years earlier than had been thought. Anyone want an obsolete paleontology book, cheap?

5. New Worlds at Last

It's official: astronomers finally have irrefutable evidence of a solar system beyond our own. But fans of alien life can't celebrate yet: the three confirmed planets are orbiting the dim remnant of a star that exploded long ago.

6. Sensible Food Labels

The U.S. Food and Drug Administration implemented a radical idea last spring: food labels that are useful to consumers. Packagers now have to display data on cholesterol, fat, protein, sodium, carbohydrates and vitamins -- and, where appropriate, reveal how much of the recommended daily allowance of these nutrients a serving of the food provides. The most startling requirement: the numbers must be based on a realistic serving size, not one too small to satisfy a hummingbird.

7. Melrose Place?

Don't fret that you're missing out on all the fun. The most scientific sex survey ever says it just isn't true that typical Americans -- especially singles -- are out having wild erotic adventures. Most of us are monogamous, married couples have the best and most frequent sex, and adultery is relatively uncommon.

8. Easier Test-Tube Babies

In vitro fertilization is an arduous process in which a woman is pumped full of drugs that force several of her eggs to mature before they are removed from her body. But a new technique involves taking out immature eggs and bringing them to maturity outside the mother. Possible benefits: freedom from harsh drugs, lower cost and maybe even a better success rate.

9. Those Loving Dinos

They were mean and bloodthirsty, sure, but such dinosaurs as Tyrannosaurus rex may well have had a more caring side. The clue is the discovery of a fossilized embryo from a carnivorous dinosaur: an oviraptor found in Mongolia. The embryo was lodged in a nest, which also contained bones from other tiny dinos that mother oviraptor might have eaten while watching over her sharp- toothed darlings. Apparently even prehistoric monsters knew how to parent.

10. A Save in Space

Russia's once mighty space program nearly lost one of the few bragging points it has left when a resupply ship had trouble docking with space station Mir last summer. If a final try had not succeeded, cosmonauts would have had to leave Mir unmanned for the first time in five years.

...And The Worst

Microscopic Mass Murderers

The arrival of the real-life thriller The Hot Zone on the best-seller list, plus outbreaks of cholera, tuberculosis, Legionnaire's disease, hantavirus, plague and -- yes -- the flesh-eating version of streptococcus bacteria, have driven home a frightening truth: the war against infectious diseases is nowhere near over. In fact, because of drug-resistant bacteria and newly emerging viruses, medical science actually seems to be losing ground.