反射星云是靠反射附近恒星的光线而发光的,呈蓝色。反射星云的光度较暗弱,较容易观测到的例子是围绕着金牛座M45七姊妹星团的反射星云,在透明度高及无月的晚上,利用望远镜便可看到

发表于:2019-01-08 / 阅读(175) / 评论(0) 分类 托福英语

We are taking a ride through the Milky Way. First, we are traveling to a place where stars are born. Even at the speed of light, 196,000 miles a second, the journey lasts for 1,500 years. We've arrived at the vast glowing cloud of gas and dust, the g

发表于:2019-01-22 / 阅读(31) / 评论(0) 分类 自然百科2011年

Look closer and there is something strange about this gas and dust. There're patches where it appears to glow. These bright glowing clouds are called nebulae. And along with the Orion Nebula, our Milky Way has some spectacular examples, the Eagle Neb

发表于:2019-01-22 / 阅读(46) / 评论(0) 分类 自然百科2011年

This is a picture of the Orion Nebula in visible light. We can see all of the gas here located in front of what we know are stars in the background, and we want to be able to look inside this nebula/ and see the stars. In infrared light in this image

发表于:2019-01-22 / 阅读(34) / 评论(0) 分类 自然百科2011年

The Aeneid by Virgil 《埃涅阿斯纪》维吉尔 Mark first read the Aeneid while he was studying Latin in high school, and he recounted the story of Aeneass quest and his desire to build a city that, he said, quoting the text in English, knows no

发表于:2019-02-01 / 阅读(29) / 评论(0) 分类 阅读空间

It looks like a hand of God reaching out into the cosmos, but NASA says the display is caused by a young and powerful pulsar. Taken by NASA's Chandra X-ray observatory from it's orbiting 360 miles above the Earth, the recently released photo of Pulsa

发表于:2019-02-16 / 阅读(74) / 评论(0) 分类 实用英语