心脏星云的核心

心脏星云的核心

ByNASA中文

2022年2月14日 In the Heart of the Heart Nebula Image Credit & Copyright: Adam Jensen Explanation: What excites the Heart Nebula? First, the large emission nebula dubbed IC 1805 looks, in whole, like a human heart. Its shape perhaps fitting of the Valentine’s Day, this heart glows brightly in red light emitted by its most prominent element: excited hydrogen. The red glow and the larger shape are all created by a small group of stars near the nebula’s center. In the heart of the Heart Nebula are young stars from the open star cluster Melotte 15 that are eroding away several picturesque dust pillars with their energetic light and winds. The open cluster of stars contains a few bright stars nearly 50 times the mass of…

夜晚的地球

夜晚的地球

ByNASA中文

2022年2月13日 Earth at Night Image Credit: NASA, Suomi NPP VIIRS; Data: Miguel Román (NASA GSFC); Processing: Joshua Stevens Explanation: This is what the Earth looks like at night. Can you find your favorite country or city? Surprisingly, city lights make this task quite possible. Human-made lights highlight particularly developed or populated areas of the Earth’s surface, including the seaboards of Europe, the eastern United States, and Japan. Many large cities are located near rivers or oceans so that they can exchange goods cheaply by boat. Particularly dark areas include the central parts of South America, Africa, Asia, and Australia. The featured image, nicknamed Black Marble, is actually a composite of hundreds of pictures remade in 2016 from data taken by the orbiting Suomi NPP satellite….

月光下的极光

月光下的极光

ByNASA中文

2022年2月12日 Aurora by Moonlight Image Credit & Copyright: P-M Hedén (Clear Skies, TWAN) Explanation: The ice was singing as light from a bright gibbous Moon cast shadows across this frozen lake, about 20 kilometers north of Stockholm, Sweden, planet Earth. In the alluring night skyscape captured on February 10, shimmering auroral curtains of light dance in the evening sky. On that northern night nature’s performance included the auroral displays fostered by a minor geomagnetic storm. Stormy space weather was the result of a coronal mass ejection, erupting from a solar prominence days earlier and brushing our fair planet’s magnetosphere. Tomorrow’s picture: planet in the dark 月光下的极光 影像提供与版权: P-M Hedén (Clear Skies, TWAN) 说明: 当凸月的月华撤落在这座位于地球·瑞典·斯德哥尔摩北边的冰冻湖泊，并投下这些暗影之时，湖冰在吟唱。这幅摄于2月10日的迷人夜景里，夜空中有荧荧生辉翩翩舞动的极光帘。在那个北方的夜晚，自然界诸多景观中的这些极光活动，则是由微弱的地球磁暴所触发的。造就这例地球磁暴的太空天气风暴，则是太阳在数天前发生日珥爆发，所产生的日冕物质抛射后来擦撞了地球的磁层。 明日的图片: planet in the dark

IC 342：隐藏的星系

IC 342：隐藏的星系

ByNASA中文

2022年2月11日 IC 342: The Hidden Galaxy in Camelopardalis Image Credit & Copyright: Daniel Feller Explanation: Similar in size to large, bright spiral galaxies in our neighborhood, IC 342 is a mere 10 million light-years distant in the long-necked, northern constellation Camelopardalis. A sprawling island universe, IC 342 would otherwise be a prominent galaxy in our night sky, but it is hidden from clear view and only glimpsed through the veil of stars, gas and dust clouds along the plane of our own Milky Way galaxy. Even though IC 342’s light is dimmed and reddened by intervening cosmic clouds, this sharp telescopic image traces the galaxy’s own obscuring dust, young star clusters, and glowing pink star forming regions along spiral arms that wind far from the…

金牛T星与欣德变光星云

金牛T星与欣德变光星云

ByNASA中文

2022年2月10日 T Tauri and Hind’s Variable Nebula Image Credit & Copyright: Dawn Lowry, Gian Lorenzo Ferretti, Ewa Pasiak and Terry Felty Explanation: The star with an orange tint near top center in this dusty telescopic frame is T Tauri, prototype of the class of T Tauri variable stars. Next to it (right) is a yellow cosmic cloud historically known as Hind’s Variable Nebula (NGC 1555). About 650 light-years away, at the boundary of the local bubble and the Taurus molecular cloud, both star and nebula are seen to vary significantly in brightness but not necessarily at the same time, adding to the mystery of the intriguing region. T Tauri stars are now generally recognized as young (less than a few million years old), sun-like stars…

海山二：现知最危险恒星的3D模型

海山二：现知最危险恒星的3D模型

ByNASA中文

2022年2月9日 Eta Car: 3D Model of the Most Dangerous Star Known Video Credit: NASA, CXC, April Hobart; Text: Michael F. Corcoran (NASA, Catholic U., HEAPOW) Explanation: What’s the most dangerous star near earth? Many believe it’s Eta Carinae, a binary star system about 100 times the mass of the Sun, just 10,000 light years from earth. Eta Carinae is a ticking time bomb, set to explode as a supernova in only a few million years, when it may bathe the earth in dangerous gamma rays. The star suffered a notorious outburst in the 1840s when it became the brightest star in the southern sky, only to fade to obscurity within decades. The star was not destroyed, but lies hidden behind a thick, expanding, double-lobed structure…

挪威上空的极光和光柱

挪威上空的极光和光柱

ByNASA中文

2022年2月8日 Aurora and Light Pillars over Norway Image Credit & Copyright: Alexandre Correia Explanation: Which half of this sky is your favorite? On the left, the night sky is lit up by particles expelled from the Sun that later collided with Earth’s upper atmosphere — creating bright auroras. On the right, the night glows with ground lights reflected by millions of tiny ice crystals falling from the sky — creating light pillars. And in the center, the astrophotographer presents your choices. The light pillars are vertical columns because the fluttering ice-crystals are mostly flat to the ground, and their colors are those of the ground lights. The auroras cover the sky and ground in the green hue of glowing oxygen, while their transparency is clear…

NGC 4651：雨伞星系

NGC 4651：雨伞星系

ByNASA中文

2022年2月7日 NGC 4651: The Umbrella Galaxy Image Credit & Copyright: CFHT, Coelum, MegaCam, J.-C. Cuillandre (CFHT) & G. A. Anselmi (Coelum) Explanation: It’s raining stars. What appears to be a giant cosmic umbrella is now known to be a tidal stream of stars stripped from a small satellite galaxy. The main galaxy, spiral galaxy NGC 4651, is about the size of our Milky Way, while its stellar parasol appears to extend some 100 thousand light-years above this galaxy’s bright disk. A small galaxy was likely torn apart by repeated encounters as it swept back and forth on eccentric orbits through NGC 4651. The remaining stars will surely fall back and become part of a combined larger galaxy over the next few million years. The featured…

宛如蓝弹珠的地球

宛如蓝弹珠的地球

ByNASA中文

2022年2月6日 Blue Marble Earth Image Credit: NASA, Apollo 17 Crew Explanation: Welcome to planet Earth, the third planet from a star named the Sun. The Earth is shaped like a sphere and composed mostly of rock. Over 70 percent of the Earth’s surface is water. The planet has a relatively thin atmosphere composed mostly of nitrogen and oxygen. The featured picture of Earth, dubbed The Blue Marble, was taken from Apollo 17 in 1972 and features Africa and Antarctica. It is thought to be one of the most widely distributed photographs of any kind. Earth has a single large Moon that is about 1/4 of its diameter and, from the planet’s surface, is seen to have almost exactly the same angular size as the Sun….

共生变星宝瓶座R

共生变星宝瓶座R

ByNASA中文

2022年2月5日 Symbiotic R Aquarii Image Credit: X-ray: NASA/CXC/SAO/R. Montez et al.; Optical: Data: NASA/ESA/STScI, Processing: Judy Schmidt (CC BY-NC-SA) Explanation: Variable star R Aquarii is actually an interacting binary star system, two stars that seem to have a close symbiotic relationship. Centered in this space-based optical/x-ray composite image it lies about 710 light years away. The intriguing system consists of a cool red giant star and hot, dense white dwarf star in mutual orbit around their common center of mass. With binoculars you can watch as R Aquarii steadily changes its brightness over the course of a year or so. The binary system’s visible light is dominated by the red giant, itself a Mira-type long period variable star. But material in the cool giant star’s…