Venus and Jupiter, two of the brightest naked-eye planets, join a thin crescent moon to create a brief "happy face" in the sky as seen in Xi'an, Northwest China's Shaanxi Province, December 1, 2008. Astronomers and star gazers across the world are keeping watch on Monday night for the rare astronomical phenomenon known as "Planetary Conjunction".

    12月1日中国西北省份陕西，西安的上空，出现了一个奇特现象。金星、木星这两个肉眼能看到的最亮的行星和月亮一起，形成了一张巨大而奇特的笑脸。全世界的天文学家和观测者都在时刻关注着这种罕见的，被成为“行星合”的天文现象。