2020 June 8
Atmospheric Ring of Venus
Image Credit & Copyright: Pete Lawrence (Digital Sky)
Explanation: Why is Venus surrounded by a bright ring? Sometimes called a ring of fire, this rare ring is caused by the Sun’s light being visible all around an object. Usually seen around the Moon during an annular solar eclipse, the ring of fire is also visible when either Venus or Mercury cross the face of our Sun. In the featured pictured taken last week, though, Venus did not pass directly in front of the Sun — the complete atmospheric ring was caused by sunlight defracting around the planet. Venus passed within one degree of the Sun during its inferior conjunction, as it moved from the evening to the morning sky. The extreme brightness of the nearby Sun made capturing such an image very difficult — the featured image was only made possible by using a temporary filter to block direct sunlight. The image was captured from Thorton, Leicestershire, UK. The pervasive blue sky glow indicates that the image was actually captured during the day.
Tomorrow’s picture: orion’s mountains
说明: 为什么金星旁边镶着一圈亮环？因为阳光从这个天体的周围透射过来，所以形成这种或称为火之环的景观。火之环通常在日环食期间最常出现在月盘的周围，而金星或水星凌日时也会出现这种景观。在上星期拍摄这幅主题影像时，金星其实并未直接通过太阳前方，不过阳光还是受到金星厚重大气 折射造成了这圈环拱金星的亮环。在这次的下合事件里，从夜晚移向清晨天空的金星，于下合的位置时，它与太阳的间距小于1度。在极端明亮的太阳旁拍摄这种影像的难度极高，之所以能在英国．莱斯特郡．桑顿村取得这张影像，是因为滤镜暂时遮住了直射的阳光。影像中无所不在的蓝天辉光表明此时实际上是在白天。
明日的图片: orion’s mountains