SNIPPETS - Getting intimate with asteroid Ceres

Getting intimate with asteroid Ceres

Ceres, the largest asteroid in the Solar System, is finally getting its close-up. NASA’s Dawn spacecraft arrived in March, and is now taking photographs from as close as 4,400 km above the asteroid’s surface. Craters and mountains are coming into view, but the bright spots that dapple Ceres’s surface remain its most mysterious feature.

A central, 9-km-wide bright spot in a 90-km-wide crater is accompanied by a cluster of smaller reflective spots off to the right. The spots could be made of ice, salt or another type of bright material, yet to be fully understood. Data from a neutron detector on the spacecraft, which could help to answer the question, take some time to accumulate. Ceres - technically a dwarf planet - is thought to consist of at least one-quarter water; craters with ice-rich peaks are common on other bodies in the Solar System, such as Jupiter’s moons Ganymede and Callisto.

Ceres is notoriously dark, but a colour camera aboard Dawn snapped a sequence of a cratered region in the asteroid’s northern hemisphere: a true-colour view showing its dark surface, a black-and-white version processed to bring out contrast in the craters and a near-infrared image in which the brightest areas are the warmest and the darkest areas the coolest.

A large impact crater in the southern hemisphere of Ceres shows a complex series of fractures, all probably related to whatever object pummelled the asteroid and left behind this blemish. To the left, two semi-curved streaks run parallel to one another, for reasons still unknown. Mission scientists say that Ceres seems to have more geological activity than does the asteroid Vesta, which Dawn visited in 2011-12.
Alexandra Witzes

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Scientists see neurons change as memories form
Learning can be traced back to individual neurons in the brain, according to a new study. “What we wanted to do was see if we could actually create a new association - a memory - and see if we would be able to see actual change in the neurons,” said Matias Ison, a neuroscientist at the University of Leicester in England and one of the study’s authors.
He and his colleagues were able to monitor the brain activity of neurosurgical patients at UCLA Medical Centre. The patients already had electrodes  implanted in their medial temporal lobes for clinical reasons. The patients were first presented with images of notable people- like Jennifer Aniston, Clint Eastwood and Halle Berry. Then, they were shown images of the same people against different backdrops - like the Eiffel Tower, the Leaning Tower of Pisa and the Sydney Opera House.

The same neurons that fired for the images of each of the actors also fired when patients were shown the associated landmark images. In other words, the researchers were able to watch as the patients’ neurons recorded a new memory - not just of a particular person, but of the person at a particular place. The research could help scientists better understand how the brain encodes and stores new memories, Matias said.
Sindya N. Bhanoo