月出与山影

2020 March 14

Moonrise and Mountain Shadow
Image Credit & Copyright: Daniel Lopez (El Cielo de Canarias)

Explanation: What phase of the Moon is 3.14 radians from the Sun? The Full Moon, of course. Even though the Moon might look full for several days, the Moon is truly at its full phase when it is 3.14 radians (aka 180 degrees) from the Sun in ecliptic longitude. That’s opposite the Sun in planet Earth’s sky. Rising as the Sun set on March 9, only an hour or so after the moment of its full phase, this orange tinted and slightly flattened Moon still looked full. It was photographed opposite the setting Sun from Teide National Park on the Canary Island of Tenerife. Also opposite the setting Sun, seen from near the Teide volcano peak about 3,500 meters above sea level, is the mountain’s rising triangular shadow extending into Earth’s dense atmosphere. Below the distant ridge line on the left are the white telescope domes of Teide Observatory

Tomorrow’s picture: comet blizzard

月出与山影
影像来源及版权：Daniel Lopez（El Cielo de Canarias）

说明：当月亮、地球与太阳的夹角为3.14弧度时，月亮的相位是什么？当然是满月！虽然在此前后的几天里，月亮看起来可能是圆的，但只有当其黄经度数与太阳相差3.14弧度（即180度）时，它才是真正的满月。此时的月亮与太阳正好处在地球天空中的两头。3月9日，当太阳落下时，这轮非常圆的月亮正在对面的天空中慢慢升起。上图记录的便是在加那利群岛的特内里费岛上的泰德国家公园中看到的这一场景：从海拔3500米的泰德火山山顶附近看向月升方向，山峰巨大的三角形阴影正在逐渐升高，并延伸到地球稠密的大气层中；在画面左侧，远处山脊上的建筑是泰德天文台的白色望远镜圆顶。

明天的照片：comet blizzard