May 1991 天象
观测地点：Beijing (39.904°, 116.407°)
月度天象概览
24 天文事件合计，包括 4 月相和 1 行星事件。
每日天象
所有时间均为本地时间 (Asia/Shanghai)
| 日期 | 日出/日落 | 月出/月落 | 月相 | 天象 |
|---|
Planetary outlook
May 1991 mid-month observing conditions
Mercury
Observation tip: Visible to the naked eye; Mercury stays close to the Sun; best seen at dusk or dawn
Venus
Observation tip: Very bright, easily visible to the naked eye; Venus is the brightest planet and is best seen at dusk or dawn
Mars
Observation tip: Visible to the naked eye; Its reddish appearance is obvious; it is best observed near opposition
Jupiter
Observation tip: Very bright, easily visible to the naked eye; Its moons are easy to spot and it is excellent for telescope observing
Saturn
Observation tip: Visible to the naked eye; Saturn’s rings require a telescope to see clearly
Uranus
Observation tip: Binoculars are recommended; Binoculars or a telescope are recommended
Neptune
Observation tip: A telescope is required; A telescope is required; Neptune appears blue-green
Moon
Observation tip: Moon illumination 1.1%; good for observing lunar surface detail
1991 sky events by month
Choose a month to explore the detailed forecast