Published online 20 December 2006 | Nature | doi:10.1038/news061218-10


2006 in review

A romp through ten of this year's big science developments.

Here's a question that 2006 strove valiantly to answer: what, exactly, is a planet, and is Pluto one?

This might seem a silly and inconsequential matter, and perhaps space enthusiasts were more taken by the latest snaps showing recent water flow on Mars, the crash-landing mission to the Moon, or even the ill-fated X-Prize Cup. But for astronomers, the debate about how to define a planet got very, very heated.

We reports/internationalastronomical_union/">blogged the brouhaha live from the International Astronomical Union meeting in Prague, where researchers concluded that Pluto, along with several other planetary contenders, is only a 'dwarf planet'. All those lists of our Solar System's nine planets end the year by being wrong — although the debate is likely to continue at the next meeting in 2009.

The drug trial that went horribly wrong

A graver matter was this year's drug trial that ended in disaster : an experimental drug that manipulates the immune system caused serious trauma and permanent injury to many of the volunteers in the phase I trial. The trial grabbed headlines with witness quotes about participants feeling as if their heads were about to explode, and also raised questions about how drug trials are conducted, and the wisdom of tinkering with the immune system. The repercussions are still being felt.

Disaster-struck Indonesia

Before (above) and after (below). You can see the source of the mud in the centre, and the attempts to wall it in.Before (above) and after (below). You can see the source of the mud in the centre, and the attempts to wall it in.CRISP 2004

More natural disasters struck the people of Indonesia, still recovering from the tsunami of 2004. On Java, Mount Merapi threatened to blow its top, aggravated in part by a major earthquake some days later. More than 5,000 people died in the quake, although the volcano quietened down. Another major quake in July caused a local tsunami that triggered warnings but still took at least five lives. And then a mysterious mud flow sprang up in east Java after an oil company drilled into the land. The flow has brought havoc to the local people and environment, and shows no sign of stopping. Geologists say it may never stop .

Muddled over methane

Perhaps the most befuddling research of the year involved the greenhouse gas methane. First it emerged that plants — not just rice paddies and bogs, but forests — might produce more of the gas than thought, a bizarre conclusion that has no known mechanism and has left many unconvinced. Other research into the gas brought bad news: it seems the apparent levelling off of methane emissions is just a result of natural declines masking rising human sources. And that won't last — not with the permafrost melting .

The inconvenient truth of climate change

Al Gore points to a warming world.Al Gore points to a warming world.2006 by Paramount Classics/Photo By: Eric Lee

The bad news from 2006 was that global greenhouse-gas emissions are speeding up , and ever-more evidence shows that Greenland and Antarctica are losing ice. But at least it looks like the tide of opinion may be changing in the United States. Al Gore's slide-show-turned-film An Inconvenient Truth has had a big impact. And the US Supreme Court has heard, although not yet decided on, a landmark case attempting to force the US Environmental Protection Agency to regulate emissions. Even economists look to be taking climate change seriously — as shown by the worldwide attention devoted to UK chief economist Nicholas Stern's report on global warming's impact on the world's finances.

Genetic complications

Genetic research saw several surprise results this year — from a mapping of the human genome that revealed how humans may be more different from each other than was thought, to studies showing mechanisms of inheritance that go against textbook descriptions. In mice and plants, we no longer think that characteristics pass to offspring solely via DNA. The whole idea of DNA and genes being straightforward seems to have unraveled.

Medics on trial

Valya Chervenyashka, one of five Bulgarian nurses on death row in Libya.Valya Chervenyashka, one of five Bulgarian nurses on death row in Libya.Fred Abrahams/Human Rights Watch 2005

In Libya this year, a fight has been waged in court and in the press over the fate of five Bulgarian nurses and a Palestinian doctor, who were accused of deliberately infecting children with HIV. Scientific experts provided evidence that the medical team are not guilty, and wrote reports, published research, and made their findings widely known. Their evidence shows that the outbreak began several years before the accused began working at the hospital in 1998 and that it was probably caused by poor hygiene at the hospital. Yet the group was sentenced to death by the Libyan court this December. The medical team can appeal once more to the Supreme Court — as this story went to press it was uncertain when this would happen.

The case has highlighted, some say, what happens when a government refuses to accept the presence of health problems, such as the re-use of dirty needles, in its hospitals. It is not only the lives of the medical team on trial that are at stake in this story, but those of thousands of children in African hospital wards who are still at risk of infection.

Seeking stem cells

George Bush vetoed a bill that could have seen more stem-cell lines opened up to research in the United States, while the European Union voted to fund some work with human embryonic stem cells, with restrictions. Controversy over the ethical and religious implications of such work rages on. But there was also progress in efforts to make embryonic stem-cell lines without destroying an embryo — either by not harming the embryo (also done in mice this year) , or by extracting cells from an embryo that had died naturally.

A fizzle heard around the world

South Koreans express their outrage at North Korea's nuclear test.South Koreans express their outrage at North Korea's nuclear test.AP/EMPICS

North Korea grabbed the attention this year by testing both a missile and a nuclear device — neither of which seemed to go perfectly. Their smaller-than-average may have made a relatively small bang, but it still reached the ears of politicians desperate to halt the county's nuclear advance. Despite international talks, no firm agreements have been reached — although reports from North Korea indicate that ageing equipment and a lack of raw material may hamper the country's nuclear ambitions.

Russian recluse spurns prize

Perhaps the strangest story of the year was mathematical. A reclusive Russian who seems to have cracked one of the Clay Prize problems declined both the Fields Medal and its Cdn$15,000 (US$13,000) cash prize. If Grigory Perelman's proof of the Poincaré conjecture is deemed to deserve the US$1 million offered by the Clay Mathematics Institute, there are hints he may decline that too.

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