《自然》杂志25日报道了詹姆斯·韦布空间望远镜（JWST）直接成像的一颗小型气态巨行星。这是"韦 布"在其运行期间发现的首颗系外行星，标志着其向直接成像更小的、与地球质量接近的行星的目标迈 出了重要一步。这一发现填补了人们对太空认知的空白，有助于理解早期行星的形成过程及原行星盘内 的动态变化。 新发现不仅代表了对更小质量系外行星研究的重大突破，也为未来的探索奠定了基础。下一步JWST有 望捕捉到质量仅为木星10%的系外行星图像，这将极大地促进人们对类地行星的认知。此外，随着更先 进成像技术的发展，无论是空间还是地面望远镜都将拥有更强的搜索系外行星能力，从而进一步揭开宇 宙秘密。 当代天文学的一个主要目标是寻找并研究系外行星。自2022年开始运行以来，JWST为科学家提供了前 所未有的机会来详细地研究已知系外行星。此次，JWST捕捉到了迄今为止通过直接成像方法观测到的 质量最小的系外行星。这类行星相对较暗，并且其信号容易被母星光芒所掩盖，对其成像是一个巨大的 技术挑战。 （文章来源：科技日报） 为克服这一难题，法国国家科学研究中心巴黎天文台研究团队开发了一种特殊的日冕仪，并将其安装在 JWST的MIRI仪器上。 ...

COSMOS-Web图谱回溯至大爆炸后约3亿年，彼时宇宙刚刚点亮第一批恒星。JWST比哈勃空间望远镜 的主镜大了约6倍，因此其光收集能力和灵敏度大幅提升。这使得团队不仅可看到更遥远的星系，还能 观测到许多过去从未发现的天体。 科技日报记者 张佳欣 JWST所拍摄到的远古星系数量，远远超出预期。人们原以为在宇宙诞生后的5亿年内，星系应该极为稀 少，但JWST却在这一时期发现了比哈勃预测多出10倍的星系。更令人惊讶的是，团队还发现了一些超 大质量黑洞，而这些天体在哈勃时代是根本无法探测到的。 由多个国家科研机构联合组成的项目组6月6日正式发布了迄今最大的宇宙图谱及相关全部观测数据。该 图谱名为"COSMOS-Web"，基于詹姆斯·韦布空间望远镜（JWST）收集的数据构建，涵盖逾78万个星 系，时间跨度达135亿年，占据整个宇宙历史的98%。这些数据正在挑战人们对宇宙早期的认知。相关 论文已提交《天体物理学杂志》和《天文学与天体物理学》。 这些发现挑战了目前的宇宙演化模型。此前认为，形成一个拥有10亿个太阳质量的星系至少需要几亿 年，但新数据表明，宇宙似乎在短短几亿年内就形成了大量恒星和复杂结构。目前仍有大量细节有 ...

Core Findings - An international team led by astronomer Nikku Madhusudhan from Cambridge University has published findings in the Astrophysical Journal Letters, indicating the discovery of "the strongest evidence yet" for potential life activity in the atmosphere of the exoplanet K2-18b, located approximately 124 light-years from Earth [1] - The atmosphere of K2-18b contains chemical signatures of dimethyl sulfide (DMS) and dimethyl disulfide (DMDS), which on Earth are primarily produced by marine life, suggesting a possible biological origin [1] - This research utilized the James Webb Space Telescope (JWST) to analyze the starlight passing through the planet's atmosphere, revealing the presence of these complex organic molecules, which are more intricate than methane [1] Exoplanet Characteristics - K2-18b is one of the most common types of exoplanets discovered, with a mass approximately 8.6 times that of Earth and a volume about 2.6 times larger, situated within the habitable zone [2] - Previous studies using the Hubble Space Telescope suggested that K2-18b's atmosphere was rich in water vapor, although later analyses indicated that the observed water vapor might actually be methane [2] - The recent study confirmed the presence of methane and carbon dioxide in K2-18b's atmosphere and proposed the existence of dimethyl sulfide for the first time, achieving a detection confidence level of 3.4, which is considered a significant threshold in astronomical observations [2] Scientific Debate - There is skepticism among researchers regarding the findings, with some suggesting that the observational data may be affected by significant noise, and that reported features could be statistical fluctuations [3] - Other models could potentially explain the data with similar or even better fits, raising questions about the existence of water on K2-18b, with some researchers proposing it may resemble a gas giant like Neptune [3] - The possibility that dimethyl sulfide could originate from non-biological processes or interstellar medium has also been raised, indicating that even if detected, these compounds may not necessarily indicate life [3] Future Exploration - Various countries are developing plans to explore exoplanetary life, including China's Tianling Plan and the United States' Habitable Worlds Observatory project, reflecting a growing interest in astrobiology [4] - Advancements in astronomical telescopes, atmospheric modeling, and astrobiology are expected to enhance the understanding of potential life signals in the universe [4]