保护地球，探索宇宙，发现文明
2021年11月16日 Geminids from Gemini Image Credit & Copyright: Wang Jin Explanation: Where are all of these meteors coming from? In terms of direction on the sky, the pointed answer is the constellation of Gemini. That is why the major meteor shower in December is known as the Geminids — because shower meteors all appear to come from a radiant toward G...
2021年11月15日 Light Pillar over Volcanic Etna Image Credit & Copyright: Giancarlo Tinè Explanation: What happening above that volcano? Something very unusual — a volcanic light pillar. More typically, light pillars are caused by sunlight and so appear as a bright column that extends upward above a rising or setting Sun. Alternatively, other light pi...
2021年11月14日 How to Identify that Light in the Sky Illustration Credit & Copyright: HK (The League of Lost Causes) Explanation: What is that light in the sky? Perhaps one of humanity’s more common questions, an answer may result from a few quick observations. For example — is it moving or blinking? If so, and if you live near a city, the answ...
2021年11月13日 Rosetta’s Comet in Gemini Image Credit & Copyright: Rolando Ligustri (CARA Project, CAST) Explanation: Returning along its 6.4 year orbit, periodic comet Churyumov-Gerasimenko (67P) is caught in this telescopic frame from November 7. Sweeping past background stars in the constellation Gemini the comet’s dusty tail stretches towar...
2021年11月12日 M33: The Triangulum Galaxy Image Credit & Copyright: Bernard Miller Explanation: The small, northern constellation Triangulum harbors this magnificent face-on spiral galaxy, M33. Its popular names include the Pinwheel Galaxy or just the Triangulum Galaxy. M33 is over 50,000 light-years in diameter, third largest in the Local Group of galaxie...
2021年11月11日 NGC 1333: Stellar Nursery in Perseus Image Credit & Copyright: Michael Sherick Explanation: NGC 1333 is seen in visible light as a reflection nebula, dominated by bluish hues characteristic of starlight reflected by interstellar dust. A mere 1,000 light-years distant toward the heroic constellation Perseus, it lies at the edge of a large, st...
2021年11月10日 Video of a Green Flash Video Credit & Copyright: Paolo Lazzarotti Explanation: Many think it is just a myth. Others think it is true but its cause isn’t known. Adventurers pride themselves on having seen it. It’s a green flash from the Sun. The truth is the green flash does exist and its cause is well understood. Just as the sett...
2021年11月09日 All of These Space Images are Fake Except One Image Credit: M. J. Smith et al. (U. Hertfordshire) Explanation: Why would you want to fake a universe? For one reason — to better understand our real universe. Many astronomical projects seeking to learn properties of our universe now start with a robotic telescope taking sequential images of t...
2021年11月08日 A Filament Leaps from the Sun Video Credit & Copyright: Stéphane Poirier Explanation: Why, sometimes, does part of the Sun’s atmosphere leap into space? The reason lies in changing magnetic fields that thread through the Sun’s surface. Regions of strong surface magnetism, known as active regions, are usually marked by dark sunspot...
2021年11月07日 The Cat’s Eye Nebula in Optical and X-ray Image Credit: NASA, ESA, Hubble Legacy Archive; Chandra X-ray Obs.; Processing & Copyright: Rudy Pohl Explanation: To some it looks like a cat’s eye. To others, perhaps like a giant cosmic conch shell. It is actually one of brightest and most highly detailed planetary nebula known, compose...