composite

"A colour is a physical object as soon as we consider its dependence, for instance, upon its luminous source, upon other colours, upon temperatures, upon spaces, and so forth." -Ernst Mach Our Sun, like all Sun-like stars, will come to the end of its life someday. All the hydrogen fuel in its core will eventually burn up, and when this happens, the core itself will begin to contract. When temperatures are finally high enough, the end product of hydrogen fusion -- Helium-4 -- will begin to fuse in the contracted core, and the Sun will expand into a Red Giant. Image credit: Northwestern…

"Building one space station for everyone was and is insane: we should have built a dozen." -Larry Niven Here on the solid ground of the Earth, the Sun and Moon rise and set on a daily basis. During the hours where the Sun is invisible, blocked by the solid Earth, the stars twirl overhead in the great canopy of the night sky. Image credit: Chris Luckhardt at flickr. In the northern hemisphere, they appear to rotate around the North Star, while in the southern hemisphere, the stars appear to rotate about the South Celestial Pole. The longer you observe -- or for photography, the longer you…

"This seems to be the law of progress in everything we do; it moves along a spiral rather than a perpendicular; we seem to be actually going out of the way, and yet it turns out that we were really moving upward all the time." -Frances Willard As spring gives way to summer here in the Northern Hemisphere, one of the most beloved sights of the night sky becomes ever more prominent: the Big Dipper. (Image credit: NASA, ESA, Z. Levay (STScI) and A. Fujii.) These seven bright stars shine high above the horizon after sunset, and will continue to do so over the rest of the Spring and all Summer…