保护地球，探索宇宙，发现文明
研究人员用NASA的詹姆斯·韦伯太空望远镜观测，在一颗遥远行星的大气中确定了硅酸盐云的特征。在22小时的一天中，大气不断上升、混合和移动，使较热的物质上升，使较冷的物质下降。由此产生的亮度变化如此剧烈，以至于它是迄今为止已知的变化了最大的行星质量天体。由亚利桑那大学的布列塔尼·迈尔斯领导的研究团队还利用韦伯的数据非常清楚地探测到了水、甲烷和一氧化碳，并发现了二氧化碳存在的证据。这是迄今为止在太阳系以外的行星上同时发现的分子数量最多的一次。
Stars leave streaks of light in concentric circles in this March 16, 2012, view from the International Space Station. To create this composite long exposure, NASA astronaut Don Pettit combined multiple 30-second exposures from a mounted camera on the space station into one image. The orbiting laboratory travels 5 miles per second, traveling around our planet...
2023年3月22日 M31: The Andromeda Galaxy Image Credit & Copyright: Abdullah Al-Harbi Explanation: How far can you see? The most distant object easily visible to the unaided eye is M31, the great Andromeda Galaxy, over two million light-years away. Without a telescope, even this immense spiral galaxy appears as an unremarkable, faint, nebulous cloud in the c...
This Feb 3, 2023, enhanced-color image from Landsat 9 highlights a green and blue patchwork pattern in flooded rice fields in southwestern Louisiana. Raised levees used for water management form the grid pattern between the fields, which appear dark blue. As it flowed through several southern states over tens of thousands of years, the Mississippi River left...
2023年3月21日 Dark Nebulae and Star Formation in Taurus Image Credit & Copyright: Vikas Chander Explanation: Can dust be beautiful? Yes, and it can also be useful. The Taurus molecular cloud has several bright stars, but it is the dark dust that really draws attention. The pervasive dust has waves and ripples and makes picturesque dust bunnies, but perhaps...
奥德赛号是一艘有几十年历史的没有燃料表的航天器，测量其燃料供应绝非易事。自从NASA在22年前（2001年）发射了火星奥德赛轨道飞行器到红色星球以来，这艘宇宙飞船已经绕火星飞行了94,000多次。这大约相当于13.7亿英里（22.1亿公里），这一距离需要对航天器的燃料供应进行极其谨慎的管理。鉴于奥德赛没有燃油表，这一壮举更加令人印象深刻；工程师们不得不转而依赖数学。
Titan, Saturn’s largest moon, looks quite small in comparison to the giant planet behind it in this natural color view from the Cassini-Huygens spacecraft. This image from Aug. 29, 2012, also shows seasonal changes occurring on Saturn; as spring comes to the northern Saturnian hemisphere, the azure blue seen fades, while winter in the south adds a bluish hue...
2023年3月20日 M1: The Expanding Crab Nebula Video Credit & Copyright: Detlef Hartmann Explanation: Are your eyes good enough to see the Crab Nebula expand? The Crab Nebula is cataloged as M1, the first on Charles Messier’s famous list of things which are not comets. In fact, the Crab is now known to be a supernova remnant, an expanding cloud of debri...
2023年3月19日 Equinox at the Pyramid of the Feathered Serpent Image Credit & Copyright: Robert Fedez Explanation: To see the feathered serpent descend the Mayan pyramid requires exquisite timing. You must visit El Castillo — in Mexico’s Yucatán Peninsula — near an equinox. Then, during the late afternoon if the sky is clear, the pyramid&#...
2023年3月18日 Wolf-Rayet 124 Image Credit: NASA, ESA, CSA, STScI, Webb ERO Production Team Explanation: Driven by powerful stellar winds, expanding shrouds of gas and dust frame hot, luminous star Wolf-Rayet 124 in this sharp infrared view. The eye-catching 6-spike star pattern is characteristic of stellar images made with the 18 hexagonal mirrors of the James ...