Year in science: Dig into DNA, out-of-this-world discoveries

— -- Distant worlds envisioned. Cellular secrets revealed. The subatomic world cracked open. Science hinted at a tantalizing future in 2008 with pictures of planets circling nearby stars, skin cells remade into embryonic tissues and the inauguration of the world's largest science experiment in Europe. "It was a good year for science," says news editor Robert Coontz of Science magazine. Take a look back at the stars of the Year in Science.

Flying through Saturn's moon's plume

NASA probes added to a legacy of daring space flybys, passing fairly close to Mercury and Saturn's mystery moon, Enceladus, including a 14-mile-high skim through a geyser plume. A lively scientific debate has erupted along with those plumes between scientists who suggest a lake lies hidden under the ice crust of Enceladus and those who disagree. Of all the discoveries at Saturn made by the Cassini spacecraft, a collaboration with the European Space Agency, "none has been more thrilling or carries greater implications" than the water jets blasting out of the south pole of Enceladus, said imaging team leader Carolyn Porco of the Space Science Institute in Boulder, Colo., at a recent science meeting.

In October, NASA's MESSENGER spacecraft sped just 124 miles above the Mercury, mapping never-before-seen territory on the solar system's innermost planet. The flight revealed 30% of Mercury previously hidden from view, a land area equal to the size of South America, and showed that the crust of the planet is a mishmash of materials, with ancient impact craters mixed with lava flows on the surface.

Findings about stem cells multiply

A crescendo of discoveries pushed stem cells from the lab dish to news headlines this year. Only two years ago, a Japanese research team led by Shinya Yamanaka of Kyoto University announced a method for turning mouse skin cells into unspecialized ones that resembled embryonic stem cells, prized by biomedical researchers for the potential to turn into any kind of tissue. This year, teams made use of the discovery in human cells to earn "Breakthrough of the Year" status from Science magazine.

For the first time, two teams created families of induced pluripotent cells — unspecialized cells derived from specialized cells — from patients suffering 11 different diseases, including Parkinson's disease and juvenile diabetes. And a team led by Harvard's Doug Melton demonstrated "lineage switching" in a Nature journal study, switching ordinary kidney cells into specialized tissues that produce insulin in mice. The end goal of cell reprogrammers is to create immune-system-friendly transplant tissues for patients.

Science bummer: LHC shut down

Europe's Large Hadron Collider was a mixed blessing. The world's most complicated science experiment is designed to explore the creation of the universe. On the plus side, the world did not end, despite some fears that the $6 billion atom smasher would create black holes, gravitational pits from which not even light can escape. But nine days after start-up, it was shut down by a liquid hydrogen leak and damage to magnets guiding the particle beams within its 5.3-mile-wide ring. "No one expected the LHC not to have some hurdles, and this was not a showstopper," says Phillip Schewe of the American Institute of Physics.

Genome mapping gets personal

The age of the personal genome, an entire genetic map of a single person, began this year as 10 volunteers on a Harvard University project, including lead scientist George Church, released genome details in October. "We're all shockingly healthy," Church said.

A month later, Nature magazine reported on individual genomes of a man from China and another from West Africa in separate studies. "Already researchers are gearing up to sequence thousands of genomes, both to discover the true nature of human variation, and very important to determine the full spectrum of mutations that cause cancer," said Illumina Cambridge's David Bentley, who led the West African study.

Researchers hope to pioneer a field of personalized medicine.

Planets that really are out of this world

The hunt for an Earth-like planet orbiting a nearby star acquired new focus with the first images of nearby solar systems in November. A star about 128 light-years away named HR 8799 was orbited by three planets in NASA images, along with another possible planet spotted orbiting the star Fomalhaut. French astronomers from the European Southern Observatory contributed their own potential planet, which was spotted orbiting the star Beta Pictoris.

The planet pictures rely on better techniques for screening starlight from the infrared radiation (heat) emitted by planets. The planets are all massive worlds bigger than Jupiter and at least eight times farther out from their star than Jupiter is from our sun at 483 million miles. Still, scientists are closing in on smaller planets closer to their stars, says Christian Marois of the National Research Council Canada, who led the HR 8799 study.

Astronomers have detected more than 330 planets orbiting nearby stars, including a handful only a few times larger than Earth, by indirect means. Expect more news early next year when the European Space Agency's COROT mission reveals its findings of "transit" planets, revealed by the dimming of light from a star when an orbiting planet eclipses its light. NASA's Kepler mission, which uses the same method to look at more stars further away, will also launch later next year. The end goal is detection of a planet like Earth around a star like the sun in coming decades.

Ancient DNA gets its day in the sun

Extinct species enjoyed a good year — well, as good as you can have when you are extinct — thanks to genetic technologies. A team led by Richard Green of Germany's Max Planck Institute in August unveiled a complete map of the mitochondrial DNA of a 38,000-year-old Neanderthal. Mitochondrial DNA is found throughout cells and the results showed significant differences with human DNA.

And then it was the woolly mammoth's turn. A team led by Webb Miller of Penn State reported the genome of the vanished pachyderms in Nature. The genes reveal that mammoths split from African elephants about 1.5 million years ago.

Maya blue colored their worldview

The mystery of Maya blue — the hardy blue pigment used by the ancient Maya to decorate pottery, murals and human sacrifices — appears to have yielded to archaeological science this year. Examining a 14-foot thick layer of blue residue lining the bottom of a natural well, the Sacred Cenote, in Mexico's Yucatan, researchers from Chicago's Field Museum and Wheaton (Ill.) College figured out how Maya blue was made.

Evidence suggests the pigment was baked from clay and incense as part of human sacrifices, says the study in the journal Antiquity. More than 100 bodies, plus blue pots, rained into the well from A.D. 300 to 1500 to create the thick pigment layer.

Kuttamuwa was a soul man

At an archaeological site in Turkey this summer, a University of Chicago team reported the discovery of an 800-pound, 3-foot-tall inscribed basalt stone, called a stele, bearing intriguing insights into Iron Age conceptions of the afterlife. A cremation inscription for Kuttamuwa, an official in a city then part of the Assyrian Empire, refers to one offering — "a ram for my soul that is in this stele."

"It's the first inscription to make really clear what these people understood about the afterlife in terms of the soul," archaeologist David Schloen wrote in Archaeology, which named the eighth-century B.C. stele one of its top discoveries for 2008. The ancient Egyptians had developed a sense of the soul thousands of years earlier, but the stele confirms that a sense of the soul separate from the body also existed.

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