Science news roundup for week ending 14/10/12:
(Originally published 12/10/12, on 24n.biz. Thumbnail image courtesy of NASA)
The Dragon docks: In a milestone of commercial spaceflight the first such mission to resupply the International Space Station (ISS) successfully docked with the station early this Wednesday. The unmanned Falcon 9 rocket launched from Florida on Sunday, succesfully putting its Dragon capsule into orbit bound for the ISS carrying 1,000 pounds of gear, science experiments and supplies. After a demonstration run without essential cargo in May, this is the first of 12 operational missions planned in a $1.6 billion contract between NASA and California-based company Space Exploration Technologies Corp. (SpaceX), owned by Pay-Pal co-founder Elon Musk. NASA is relying on private companies after retiring its space shuttle fleet last year to concentrate on manned missions beyond low Earth orbit, such as to Mars. One of the rocket’s nine engines lost pressure and shutdown during the launch, but SpaceX said the Falcon 9 was designed to handle such problems. It failed to put the commercial communication satellite that was its other cargo into the correct orbit however, but engineers are working on raising the orbit with the satellite’s on-board propulsion system. The Dragon will remain at the ISS for nearly three weeks before returning to Earth with almost 2,000 pounds of samples, experiments and used equipment.
Diamond in the sky: Scientists at Yale University announced yesterday that a nearby planet twice the size and eight times the mass of Earth, could be composed largely of diamond. The planet, 55 Cancri e, is one of five orbiting a star (55 Cancri), visible to the naked eye, 40 light years away in the constellation of Cancer. It orbits this star at hyper speed, giving it a year of just 18 hours, and its surface temperature is around 3,900 degrees Fahrenheit. Astronomical radius measurements and recent estimates of its mass allowed the Yale-led team to infer the planet’s chemical composition by modelling its interior and calculating all possible combinations of constituents that could produce a rocky planet with exactly these characteristics. The study, due to be published in Astrophysical Journal Letters, suggests the planet has no water and is composed of carbon (in the form of graphite and diamond), iron, silicon, carbide, and possibly silicates, and that at least a third of its mass – equivalent to three Earths – could be diamond.
Sweet nurture: Psychologists at the University of Rochester, New York, have shown that children’s ability to delay gratification is at least as influenced by rational decisions about the probability of future rewards, as it is on innate ability or character. The study, published online in Cognition yesterday, revisited a classic experiment published in 1972 known as the “marshmallow study”. In the experiment toddlers were presented with a treat and told they could either eat it when they chose, or, if they could wait 15 minutes, they would get two. Not only were most unable to wait, but follow up studies showed a strong association between how long they were able to wait and various measures of health, competence and success in later life. A recent Imaging study even found differences in key brain areas between adults who could and could not delay as children. The Rochester team manipulated the “reliability” of their toddlers’ environment by preceding a classic marshmallow test with similar scenarios involving an art project. A researcher gave the children some meagre art materials and told them if they could wait, she would return with better supplies. In a “reliable” condition, this is what she did, but in an “unreliable” condition, she returned minutes later to explain she had been wrong and didn’t have any better materials after all. All the children then took part in a marshmallow test. Those in the reliable condition lasted an average of 12 minutes before giving in, whereas those in the unreliable condition lasted only three. These effects are even larger than those found in previous research looking at things like teaching the children effective waiting strategies. All of which suggests that children’s willingness to delay gratification reflects rational decision making based on the probability of reward, as much as anything innate.