星空有约｜水星19日迎西大距，黎明时分显露真容

Core Viewpoint - The article discusses the upcoming western elongation of Mercury on August 19, which presents the best observation conditions for the planet this year, allowing the public to potentially view it in the early morning sky if weather permits [1][2]. Group 1: Observation Conditions - Mercury will be at a horizontal height of approximately 18 degrees at sunrise, with a brightness of 0 magnitude, making it visible to the public [2]. - The observation of Mercury is not limited to August 19; the days surrounding this date also provide good opportunities for viewing due to minimal changes in the planet's height [3]. Group 2: Characteristics of Mercury - Mercury is the most challenging planet to observe in the solar system due to its proximity to the Sun, often being obscured by sunlight [1]. - The planet completes its orbit around the Sun in just 88 days, resulting in 3 to 4 occurrences of both eastern and western elongations each year, with varying observation conditions based on its position relative to the Sun [1].