On the summit of Haleakala, a dormant volcano on the island of Maui in Hawaii, a telescope began clicking pictures of the night sky in 2010. Over the next four years, Pan-STARRS, short for Panoramic Survey Telescope and Rapid Response System, photographed the entire sky, as seen from Hawaii, 12 times in five colors of visible and infrared light. In December, the astronomers who operate Pan-STARRS released the first results from their survey. Their big data universe lists the positions, colors and brightness of 3 billion stars, galaxies and other objects. It amounts to 2 petabytes of data, roughly equivalent to 1 billion selfies. All this information resides in the Mikulski Archive for Space Telescopes at the Space Telescope Science Institute in Baltimore, where any astronomer can access it. A big goal of the project is to discover moving objects like asteroids so that we can visit them and perhaps steer them away before they visit us, as well as to discover supernovas and other rare violent events while they are exploding.

Slime molds don’t need brain to learn

A slime mold doesn’t have eyes for watching, a mouth for communicating or a brain for thinking. It doesn’t even have neurons, for crying out loud. It is exactly what its name suggests: a weird-looking, single-celled blob of goo. But it can learn. And it can teach its friends. This discovery comes in a study published in the journal Proceedings of the Royal Society B. Scientists in France taught some 2,000 slime molds to avoid nasty-tasting substances while searching for food — and found that the molds could then transmit this behavior to their compatriots simply by fusing with them.

Warming blamed for lackluster snowpack

On Tuesday, state water officials trudged into the Sierra Nevada for the first snowpack survey of 2017. The reading at Phillips Station, near Lake Tahoe, is a largely ceremonial exercise, attracting attention in part for its visual interest. After dipping poles into the snow, surveyors said the snowpack was at roughly half the historical average. Electronic readings across the whole of the Sierra Nevada indicated the snowpack was about 70 percent of normal. Scientists say warming temperatures have worked to suppress the snowpack. “Just about every year since 2000 has been warmer than the preceding year,” said Doug Carlson, a spokesman for the California Department of Water Resources. “So this is where global warming is really seen in our data here in California.” The lackluster readings could spell trouble in the spring and summer, when California relies on runoff from the mountains to meet a third of its water needs.

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