8 October 2011 | NewScientist | 7

“Some villages in Tokelau only have enough water until the end of this week,” says Jo Suveinakama of the Tokelau government.

A weak La Niña weather system is causing the drought by cooling the surface of the sea around Tuvalu, says Daniel Corbett of forecasters MetService in Wellington, New Zealand. The cool waters have forced a large band of cloud off course. “Normally the band would be producing afternoon showers over the islands,” says Corbett. “But now it’s too far south, so they have been bone dry.” The clouds are not expected to return until next year.

Anti planet-hackingIT’S a different kind of anti-hacking campaign. Political opposition to technologies that could cool the planet is in full swing. A geoengineering field test, led by Matthew Watson of the University of Bristol, UK, and planned for October in Sculthorpe, has been postponed for six months.

The idea was to use a kilometre-long hose to pump water into the atmosphere. Larger versions could pump sulphate aerosols into the stratosphere, cooling the Earth. The UK’s Engineering and Physical Sciences Research Council, which is funding the project, says the delay was recommended by an independent panel to allow external parties to air their concerns. The decision follows a campaign by environmental lobbyists the ETC Group, based in Ottawa, Canadia.

Meanwhile, the European Parliament has passed a resolution that “expresses its opposition to proposals for large-scale geoengineering”. If the other bodies that make up the European Union approve it, the EU would then be committed to an anti-geoengineering stance for the UN Conference on Sustainable Development in Rio de Janeiro, Brazil, in June 2012.

Asteroids plummetGOOD news, Earthlings. There are fewer large, near-Earth asteroids – which could potentially crash into Earth – than previously thought.

The news comes from an infrared sky survey by NASA’s WISE satellite. Rather than relying on reflected sunlight to detect space rocks, as visible-light surveys do, WISE picked up the heat they emit. The technique is more sensitive because it depends less on the rocks’ colour.

Amy Mainzer of NASA’s Jet Propulsion Laboratory in Pasadena, California, and

colleagues used the new census to estimate that there are 19,500 near-Earth asteroids between 100 and 1000 metres across, about half as many as previously thought.

The researchers also report that more than 90 per cent of the 981

“planet buster” asteroids – those larger than 1 kilometre across – have been identified. This meets a target set by the US Congress in 1998 (arxiv.org/abs/1109.6400).

“An infrared sky survey suggests there are fewer large, near-Earth asteroids than previously thought”

RARELY has the role of DNA evidence in court been discussed so publicly and in such detail. When Amanda Knox and Raffaele Sollecito were cleared on Monday of murdering British student Meredith Kercher in 2007, the judge said the evidence linking the two to the murder was “not reliable”.

The case has raised the issue of whether international standards for forensic analysis should be enforced. At the moment there is no global agreement on how procedures are carried out.

“Forensics comes out of a frontier mentality, with one lab pushing the boundaries and testing new techniques,” says Greg Hampikian of Boise State University in Idaho, who reviewed the DNA evidence in the

Kercher murder. He says successful forensics often come from a lab trying something new, testing its validity in court, and then making the procedure standard. “Low-template number DNA, like they attempted to use in the Knox case, that’s one of these new frontier areas.”

In June, court-appointed forensic experts from Rome’s Sapienza University concluded that Italy’s police forensic science laboratory had not followed the correct procedure for testing small amounts of DNA. The lab is a member of the European Network of Forensic Science Institutes, but Wim Neuteboom of the ENFSI says the network is not considering imposing stricter regulations on members in light of the Kercher case.

Knox trial exposes forensic flaws

–Homeward bound–

reute

rs

60 SEcondS

Heavenly Palace in orbitChina launched its first prototype science lab into space on 29 September. Called Tiangong 1, or Heavenly Palace, the 10.4-metre-long uncrewed lab is an important step in China’s plans to have a large, crewed space station orbiting Earth by 2020.

Cheaper DNAIt’s not quite the much-anticipated $1000 genome, but some people will soon be getting their “exome” – the 1.5 per cent that codes for proteins – sequenced for just $999. Last week at the Health 2.0 Conference in San Francisco, 23andMe of Mountain View, California, invited existing customers to sign up to participate in the project.

No disease pleaseIt must be love: she’s boosting her immune system. When female fruit flies hear male courtship songs, they turn on immune system genes, apparently getting ready for potential infections (Proceedings of the Royal Society B, DOI: 10.1098/rspb.2011.1644).

‘Mad cow’ still lurkingThe human form of mad cow disease is still at large in the UK, a study screening 13,878 people’s appendixes reveals. Four tested positive for variant Creutzfeldt-Jakob disease, which translates to 288 infections per 1 million people in England, the UK Health Protection Agency reports. So far, 173 people in England have died of vCJD.

Reusable rocketsToday’s space launch vehicles splash down in the sea or burn up in the atmosphere after use, taking millions of dollars with them. Upstart firm SpaceX wants to change that and last week said it aims to return its Falcon rockets to the launch pad for later reuse. The company’s aim is to ferry astronauts to the International Space Station.

For daily news stories, visit newscientist.com/news