天问一号成功观测到星际“访客”：该天体彗星特征明显，距其约3000万公里远程拍摄

Core Viewpoint - China's Tianwen-1 orbiter successfully observed the interstellar object ATLAS, marking a significant achievement in space exploration and expanding the capabilities of the Tianwen-1 mission [1][2]. Group 1: Observation Details - The Tianwen-1 orbiter observed ATLAS from a distance of approximately 30 million kilometers, making it one of the closest observations of this interstellar body [1]. - ATLAS was discovered on July 1, 2025, by a telescope in Chile and is the third known interstellar object to visit the solar system [1]. - The object has a hyperbolic trajectory with an eccentricity of 6.23, indicating it does not follow a closed orbit around the Sun [2]. Group 2: Scientific Significance - ATLAS is estimated to be between 3 billion and 11 billion years old, potentially older than the solar system, making it a rare sample for studying the composition of exoplanets and early stellar history [2]. - The ongoing research on ATLAS aims to explore the physical properties and size of the object, which is believed to have a comet-like structure with an icy nucleus [2]. Group 3: Technical Achievements - The Tianwen-1 team began preparations for observing ATLAS in early September, overcoming challenges due to the object's small size (nucleus diameter of about 5.6 kilometers) and faint brightness [3]. - The high-resolution camera on the Tianwen-1 orbiter was utilized to capture images of ATLAS, achieving a significant technical milestone by observing a target that is 10,000 to 100,000 times dimmer than Mars [4]. - The successful observation of ATLAS serves as a technical trial for future asteroid exploration missions, particularly for Tianwen-2 [4].