Alien bright lights, big city could reveal ET

Alien bright lights, big city could reveal ET

noriakimasumoto/getty IN BRIEF Come on in, the water’s lovely Alien bright lights, big city could show where ET lives IF ET enjoys urban nightlife a...

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noriakimasumoto/getty

IN BRIEF Come on in, the water’s lovely

Alien bright lights, big city could show where ET lives IF ET enjoys urban nightlife as much as we do, we might be able to spot the glittering lights of alien cities. The mainstream search for extraterrestrial intelligence (SETI) relies on the hope that aliens will either leak or broadcast radio signals out into space. In recent years, however, humanity’s own radio voice has softened with the shift to Earthward-pointed satellite broadcasts, while our cities have brightened. If we are any guide, alien hunters should look to city lights instead, argue Avi Loeb of Harvard University and Edwin Turner of Princeton University. Existing telescopes could distinguish the spectral

signature of sunlight glinting off an object at the edge of our solar system from the glow of alien street lights, they argue, while future space telescopes could detect well-lit planets around other stars (arxiv.org/abs/1110.6181). Greg Laughlin, an exoplanet hunter at the University of California, Santa Cruz, thinks this is a “good SETI search strategy”, though he doubts that alien urbanites live in the outer reaches of our solar system, so far from the life-giving glow of the sun. “This idea has its best applicability outside the solar system.” Of course, the plan could hit some practical snares. When Loeb’s home lost power for three days after a recent storm, he thought, “I hope the aliens do not use [the same] electric company, or else their lighting will not be consistent.”

Clot-hunting probe spots troublemakers THE movie Fantastic Voyage had a miniaturised submarine sent into a VIP’s bloodstream to destroy a life-threatening clot. A new probe is hot on the fictional microsub’s tail fins: it can pass through arteries to spot the most dangerous clots and deposits. Existing probes are essentially cameras that can travel inside arteries. Doctors must spot deposits and judge whether they

are likely to come loose and block an artery. The new probe, developed by Guillermo Tearney at Massachusetts General Hospital in Boston, also detects molecules that mark out the most harmful clots and fatty plaques. To test the probe, Tearney’s team first fed rabbits a diet that generated arterial deposits. They then injected them with a fluorescent chemical that tags

the danger-sign molecules. The probe carries a detector for the fluorescent light, which revealed bright areas on artery walls where the tags had found their targets. The team was able to detect a protein that causes clots to form, and an enzyme found in the most dangerous plaques (Nature Medicine, DOI: 10.1038/nm.2555). In principle, any molecule could be detected, says Tearney. And just as in the movie, lasers to zap suspicious lesions could be added.

WARM weather may have pushed the landlubber ancestors of some marine animals back to the sea. Vertebrates ventured from water onto land only once, about 365 million years ago. But since then some 31 groups have gone back the other way, including prehistoric plesiosaurs and present-day whales and dolphins. Fossils and estimates of past temperatures show that 26 of the groups took the plunge when the world was warmer than today, says Ryosuke Motani at the University of California, Davis. Warm water would help coldblooded animals to remain active as they adapted to the oceans, he says. This would be less of a problem for warm-blooded mammals and birds, but even they were more likely to take to the water during warm spells, Motani told the Society for Vertebrate Paleontology meeting in Las Vegas, Nevada, last week.

Leopard horses lived in Stone Age STONE AGE cave paintings of white horses with black spots may have depicted real animals, rather than spirit horses, as is sometimes assumed. Some archaeologists argue that no horses with “leopard” patterns had evolved 25,000 years ago. So spotted horses in cave murals from that time at Pech-Merle in France must be symbolic. Now Arne Ludwig of the Leibniz Institute for Zoo and Wildlife Research in Berlin, Germany, has analysed DNA extracted from the remains of ancient European horses, and found it contains variants of the pigment genes that produce the spotted-coat pattern in modern-day horses (Proceedings of the National Academy of Sciences, DOI: 10.1073/pnas.1108982108). 12 November 2011 | NewScientist | 19