每日天文一图展示了太阳系在银河系中的位置，并介绍了本地星际介质(ISM)。ISM由气体构成，分布不均匀，难以探测。通过观测最近恒星的光线，可以发现本地ISM吸收特定颜色。太阳正穿过本地星际云，该云正从天蝎座-半人马座恒星形成区向外流动。太阳可能在未来1万年内离开该星际云。星际边界探测器(IBEX)的观测表明，太阳系中性星际粒子的流动方向正在变化。关于本地ISM的分布、起源及其对太阳和地球的影响，仍有许多未知之处。

🔭本地星际介质（ISM）并非均匀分布，而是呈现出不规则的斑块状，即便在太阳附近也是如此。这种介质主要由氢气组成，由于其稀薄和光线微弱，直接探测非常困难。

🛰️星际边界探测器（IBEX）的观测显示，太阳目前正穿过一个被称为本地星际云的区域，这个云正从天蝎座-半人马座恒星形成区向外流动，太阳可能在未来1万年内离开该云。

🔄IBEX的测量还揭示了一个意外的发现，即中性星际粒子穿过太阳系的方向正在发生变化，这引发了关于本地ISM动态性质的进一步研究。

🌌本地星际介质的详细分布、起源及其如何影响太阳和地球，仍然是未解之谜，科学家们正在持续进行观测和研究，以揭示更多关于我们宇宙邻域的奥秘。

Astronomy Picture of the Day Discover the cosmos!Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.2024 December 22 The Local Fluff Illustration Credit: NASA, SVS,Adler, U. Chicago, Wesleyan Explanation: The stars are not alone. In the disk of ourMilky Way Galaxy,about 10 percent of visible matter is in the form of gas called theinterstellar medium (ISM). The ISM isnot uniformand shows patchiness even near ourSun. It can be quite difficult to detect thelocal ISM because it is so tenuous and emits so little light. This mostly hydrogen gas, however, absorbs some veryspecific colors that can be detected in the light of thenearest stars. A working map of the localISM within 20 light-years,based on ongoing observations and particle detections from the Earth-orbiting Interstellar Boundary Exporer satellite (IBEX), is shown here. These observations indicate that ourSun is moving through aLocal Interstellar Cloud as this cloud flows outwards from theScorpius-Centaurus Association star forming region. Our Sun may exit the Local Cloud, also called the Local Fluff, during the next 10,000 years. Much remains unknown about the localISM, including details of its distribution,its origin, and how it affects theSun and the Earth.Unexpectedly, IBEXspacecraft measurements indicate that the direction from which neutral interstellar particles flow through our Solar System is changing. APOD Year in Review: Night Sky Network Presentation for 2024 Tomorrow's picture: sky tree <| Archive| Submissions | Index| Search| Calendar| RSS| Education| About APOD| Discuss| > Authors & editors: Robert Nemiroff(MTU) &Jerry Bonnell (UMCP)NASA Official: Amber StraughnSpecific rights apply.NASA Web Privacy,Accessibility, Notices; A service of:ASD atNASA /GSFC, NASA Science Activation& Michigan Tech. U.