NEWS OF TH E WEEK
COMETS QUESTIONED AS WATER SOURCE SPACE: Rosetta spacecraft reports
high D/H ratio from comet 67P
W
ATER CONTAINED in the comet 67P/Churyu-
mov-Gerasimenko has a deuterium/hydrogen ratio vastly unlike that on Earth, a new study reports (Science 2014, DOI: 10.1126/science.1261952). The finding implies that comets may not have seeded our nascent planet with water. The results, obtained from the ROSINA instrument aboard the European Space Agency’s Rosetta spacecraft, which is orbiting the 2.5-mile-long comet, were announced at a press conference on Dec. 9. A more likely water source for Earth would be asteroids, experts now say. These planetary bodies would have still been laden with water billions of years ago, before being gradually dried by the sun. “This is a nice start to the science phase of the mission,” Matt Taylor, project scientist for the Rosetta mission, said at the conference. The idea that comets might have brought water to a cooling new Earth has a complex history. Astronomers
DRUG FIRMS PREVAIL IN ANTITRUST TRIAL VERDICT: AstraZeneca and Ranbaxy
win in Nexium pay-for-delay case DEAL BETWEEN AstraZeneca and Ranbaxy
A SHORELAN DER
Nexium is one of AstraZeneca’s topselling medicines.
Laboratories that resolved a patent dispute involving the launch of a cheaper, generic version of the blockbuster heartburn drug Nexium did not violate federal antitrust laws, a jury in Massachusetts has ruled. Bringing the case were pharmacies, wholesalers, insurers, and individual consumers who claimed they were overcharged billions of dollars as the result of a 2008 settlement that ended a patent lawsuit between the drugmakers. The six-week trial in the U.S. District Court in Boston was closely watched. It was the first since the U.S. Supreme Court ruled last year that so-called pay-fordelay agreements can harm competition but the arrangements are not always illegal. Manufacturers of generics often challenge the validity of patents on branded drugs years before they expire. In pay-for-delay deals, a brand-name pharmaceutical CEN.ACS.ORG
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ESA
Comet 67P/ ChuryumovGerasimenko, shown in this image from the Rosetta spacecraft, has water unlike that on Earth.
have long known that comets hailing from the Oort cloud that lies at the farthest regions of the solar system have a D/H ratio about twice as high as the ratio found in water on Earth. And for a while, the consensus was that comets couldn’t have been our water source. But three years ago, scientists were surprised to find Earth-like D/H ratios in the comet Hartley 2, which resides in the Kuiper belt—a region closer to the sun than the Oort cloud is. A picture then emerged of an Earth seeded by Kuiper belt comets. Rosetta’s surprising new data now show that 67P, despite being a Kuiper belt comet, has a ratio that’s very high, much higher even than that of Oort cloud comets. Michael A’Hearn, a University of Maryland emeritus astronomy professor who works on two different Rosetta instruments, says he found the result “startling,” but that it also supports his idea that comets in the Kuiper belt formed over a wide range of distances from the sun. Kathrin Altwegg of the University of Bern, in Switzerland, principal investigator for Rosetta’s ROSINA instrument, said at the conference that this new information suggests the Kuiper belt contains a mix of comets. The addition of even a few comets like 67P with high D/H ratios would be enough to raise the average ratio of all Kuiper belt comets to higher than the ratio in Earth’s water. A’Hearn believes the jury is still out, however, because early in the solar system’s history, comet groups may have been more segregated, and those that bombarded early Earth therefore may have been more uniform.— ELIZABETH WILSON
company pays a potential generics rival to abandon its patent challenge and stay off the market. In this case, the plaintiffs claimed that Indian generics maker Ranbaxy agreed to drop its challenge to London-based AstraZeneca’s Nexium patents and delay the launch of its generic version in exchange for nearly $1 billion and other compensation. They asserted that a low-cost, generic version of Nexium could have been on the market as long ago as six years. But the two drug companies argued that the plaintiffs failed to prove that Ranbaxy could have launched a generic Nexium sooner without the settlement. AstraZeneca says it would not have agreed to the private accord in 2008 if it had allowed Ranbaxy to sell a generic version of the drug before its patent expired in May 2014. The 11 jurors ultimately agreed that AstraZeneca would not have granted Ranbaxy an earlier market entry date, even without the payment. “The system worked. The jury understood the facts of the case and was not swayed by wishful thinking on the part of the plaintiffs,” says J. Douglas Baldrige, an attorney for Ranbaxy. The suit originally targeted two other generic drug makers that struck similar deals with AstraZeneca over Nexium—Teva Pharmaceutical Industries and Dr. Reddy’s Laboratories—but both settled with the plaintiffs.—GLENN HESS
DECEMBER 15, 2014
