保护地球，探索宇宙，发现文明
2020年7月6日 M43: Dust, Gas, and Stars in the Orion Nebula Image Credit: NASA, ESA, Hubble, HLA; Reprocessing & Copyright: Bryan Goff Explanation: Unspeakable beauty and unimaginable bedlam can be found together in the Orion Nebula Arguably the most famous of all astronomy nebulas, the Great Nebula in Orion is an immense interstellar molecular cloud only 1...
2020 June 17 Magnetic Streamlines of the Milky Way Image Credit: ESA, Planck; Text: Joan Schmelz (USRA) Explanation: What role do magnetic fields play in interstellar physics? Analyses of observations by ESA’s Planck satellite of emission by small magnetically-aligned dust grains reveal previously unknown magnetic field structures in our Milky Way Gala...
2020 April 14 NGC 253: The Silver Coin Galaxy Image Credit: NOAJ: Subaru, NASA & ESA: Hubble, ESO: VLT & Danish 1.5-m; Processing & Copyright: Robert Gendler & Roberto Colombari Explanation: NGC 253 is one of the brightest spiral galaxies visible, but also one of the dustiest. Dubbed the Silver Coin for its appearance in smalltelescopes, ...
2020 February 21 LDN 1622: Dark Nebula in Orion Image Credit & Copyright: Min Xie Explanation: The silhouette of an intriguing dark nebula inhabits this cosmic scene. Lynds’ Dark Nebula (LDN) 1622 appears against a faint background of glowing hydrogen gas only visible in long telescopic exposures of the region. In contrast, the brighter reflection ...
2019 October 24 Dark Seahorse in Cepheus Image Credit & Copyright: Sergio Kaminsky Explanation: Light-years across, this suggestive shape known as the Seahorse Nebula appears in silhouette against a rich, luminous background of stars. Seen toward the royal northern constellation of Cepheus, the dusty, obscuring clouds are part of a Milky Way molecular c...
2019 September 27 The Annotated Galactic Center Image Credit & Copyright: Miguel Claro (TWAN, Dark Sky Alqueva) Explanation: The center of our Milky Way galaxy can be found some 26,000 light-years away toward the constellation Sagittarius. Even on a dark night, you can’t really see it though. Gaze in that direction, and your sight-line is quickly o...
2019 August 27 Dark Dust and Colorful Clouds near Antares Image Credit: David McGarvey Explanation: Why is the sky near Antares and Rho Ophiuchi so dusty yet colorful? The colors result from a mixture of objects and processes. Fine dust illuminated from the front by starlight produces blue reflection nebulae. Gaseous clouds whose atoms are excited by ultravi...
2019 August 26 NGC 2170: Angel Nebula Still Life Image Credit & Copyright: Juan Lozano de Haro Explanation: Is this a painting or a photograph? In this classic celestial still life composed with a cosmic brush, dusty nebula NGC 2170, also known as the Angel Nebula, shines near the image center. Reflecting the light of nearby hot stars, NGC 2170 is joined...
就像灰尘会聚积在家里的角落和书架上，它们也会在太阳系中堆积起来，不同的是，星际尘埃聚成的是好几个环状的圈圈，围绕着我们的太阳。这些尘埃环恰好与行星的运行轨道重合，因为在行星绕太阳运行的时候，会通过万有引力的作用拖拽着这些星际尘埃，最终形成环绕太阳的尘埃圆环。 在大约46亿年前，太阳系从一片混沌中开始诞生，小行星相互冲击、彗星东碰西撞，星际尘埃就是由当时残存的碎石和碎屑组成的。这些星际尘埃散布在整个太阳系中，但又主要聚集在地球和金星的运行轨道上，形成满是颗粒的圆环，从地球上用望远镜就能看得到。通过研究这些星际尘埃的组成、由来和运动，科学家探寻着行星的诞生和太阳系中一切可见物质的组成。 最近的两项研究发表了太阳系内部尘埃环的新发现。其中一项研究用到了NASA的数据，概述了围绕太阳的水星轨道上存在一个尘埃环的证据。另...