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Explanation: In 2011, on January 20, NASA's NanoSail-D2 unfurled a very thin and very reflective 10 square meter sail becoming the first solar sail spacecraft in low Earth orbit. Often considered the stuff of science fiction, sailing through space was suggested 400 years ago by astronomer Johannes Kepler, who had observed comet tails blown by the solar wind. But modern solar sail spacecraft designs, like NanoSail-D2, Japan's interplanetary spacecraft IKAROS, or the Planetary Society's Lightsail A, rely on the small but continuous pressure from sunlight itself for thrust. Glinting in the sunlight as it circled planet Earth, NanoSail-D2's solar sail...

Astronomers have found a large object in the Solar System's outer reaches. It is being hailed as "a great discovery". Details of the object are still sketchy. It never comes closer to the Sun than Neptune and spends most of its time much further out than Pluto. It is one of the largest objects ever found in the outer Solar System and is almost certainly made of ice and rock. It is at least 1,500km (930 miles) across and may be larger than Pluto, which is 2,274km (1,400 miles) across. The uncertainty in estimates of its size is due to...

BERKELEY – A group of scientists at the University of California, Berkeley, is giving new relevance to the term "sharper image" by creating a superlens that can overcome a limitation in physics that has historically constrained the resolution of optical images. Schematic drawing of nano-scale imaging using a silver superlens that achieves a resolution beyond the optical diffraction limit. The red line indicates the enhancement of "evanescent" waves as they pass through the superlens. (Images by Cheng Sun, UC Berkeley)Print-quality image available for download Using a thin film of silver as the lens and ultraviolet (UV) light, the researchers...