This is a composite image of Uranus by Voyager 2 and two different observations made by the Hubble Space Telescope — one for the ring and one for the auroras. Credit: ESA/Hubble & NASA, L. Lamy/Observatoire de Paris

Unlike Earth, this icy planet’s magnetosphere opens and closes every day. More than 30 years after Voyager 2 sped past Uranus, Georgia Institute of Technology researchers are using the spacecraft’s data to learn more about the icy planet. Their new study suggests that Uranus’ magnetosphere, the region defined by the planet’s magnetic field and the material trapped inside it, gets flipped on and off like a light switch every day as it rotates along with the planet...

The Pancam on NASA’s Mars Exploration Rover Opportunity took the component images of this enhanced-color scene during the mission’s “walkabout” survey of an area just above the top of “Perseverance Valley,” in preparation for driving down the valley. Credit: NASA/JPL-Caltech/Cornell/Arizona State Univ.

NASA’s senior Mars rover, Opportunity, is examining rocks at the edge of Endeavour Crater for signs that they may have been either transported by a flood or eroded in place by wind. Those scenarios are among the possible explanations rover-team scientists are considering for features seen just outside the crater rim’s crest above “Perseverance Valley,” which is carved into the inner slope of the rim.

The team plans to drive Opportunity down Perseverance Valley after completing a “walkabout”...

Microscope photo of adipose tissue. Credit: jxfzsy/iStock/Getty Images Plus

Discovered more than 2 decades ago, the hormone leptin has been widely hailed as the key regulator of leanness. Yet, the pivotal experiments that probe the function of this protein and unravel the precise mechanism of its action as a guardian against obesity are largely missing. Flier, the HMS George Higginson Professor of Physiology and Medicine, and Maratos-Flier, HMS professor of medicine at Beth Israel Deaconess Medical Center, have made significant contributions to the understanding of the metabolism of obesity and starvation in general, and of leptin in particular.

The commentary highlights what the authors say is a startling lack of experimental evidence detailing the biologic roles of leptin in metabolism, ...

Amay J. Bandodkar et al. Soft, stretchable, high power density electronic skin-based biofuel cells for scavenging energy from human sweat, Energy Environ. Sci. (2017). DOI: 10.1039/C7EE00865A

A team at the University of California has developed a skin patch that uses human sweat as a fuel source to power an external device. Scientists and engineers are convinced that consumers want easy-to-wear consumer products—health monitors that are built into clothes, for example, or that adhere to the skin. In this new effort, they have found a way to harness human sweat as an energy source and report that the device they built was able to power a Bluetooth transmitter.

Sweat can be used as an energy source because it contains lactate, which produces energy when it oxidizes with lactate oxidase...