Although I’ve seen 77 eclipses ranging from total solars to penumbral lunars, three transits, and several stellar occultations, I had yet to see a planet occulted by the Moon. Thus, I was excited by the prospect of seeing the waning crescent Moon swing over Venus in the predawn sky last Wednesday morning, April 22nd. While the occultation was visible from much of North America, it was only in the west that the ingress would take place in a completely dark sky.
So with the chance to add something new and different to my observing accomplishments, I set my alarm for 4:30 a.m. (Oh-dark thirty, as a friend once commented). But I stepped outside to see the first cloudy sky in several days. Somewhat crestfallen, I walked to the observatory to go through the motions. However, as my eyes because more dark adapted, I could see that there was a small break in the clouds toward the east. Suddenly there was an opening that allowed me a spectacular view of the Moon and Venus separated by about a fifth of a degree. I set up “Flaire,” one of my telescopes used for imaging. The cloud wasn’t moving very much, but Venus and the Moon were rising toward it, and within a few minutes the pairing disappeared from view. It was starting to look like I’d miss the occultation.
I was disappointed, but missing an occultation wasn’t as disappointing as, say, missing a total solar eclipse. These things happen, I told myself. It’s not going to make me give away all my telescopes and take up a career as an accountant. As I looked up at the cloudy sky I thought about some of the proverbs from William Blake’s The Marriage of Heaven and Hell. Proverbs like “No bird soars too high, if he soars with his own wings;” “The road of excess leads to the palace of wisdom;” and “He whose face gives no light, shall never become a star.” These were worthy thoughts to consider in this International Year of astronomy as I watched a sky full of clouds, and no occultation.
But the sky was dynamic that morning. Clouds overhead were thickening and thinning, allowing stars behind them to appear and vanish. Then, almost on cue, the cloud to the east began to dissipate just a bit. It revealed a brightening.
Then it happened. The cloud thinned further, and the crescent Moon burst forth with part of brilliant Venus shining on its limb! The ingress had begun, but it wasn’t finished. While not exactly rivaling the diamond ring during a total eclipse of the Sun, Venus slipping behind the Moon’s limb is one of the most stunning sights I’ve seen in all my years of stargazing.
Half a minute later it was over. The thin Moon resumed its normal appearance. Venus was hidden from view. The clouds thickened once more. On this night, it took only an instant to capture one of nature’s most glorious wonders.