We don’t star gaze anymore like we used to. For one, the collective ground light from our cities, towns and commercial farms have all but washed out the brightest celestial objects that are visible on Earth without the aid of telescopes. For another, we no longer wind down the day by sitting on the front porch as the world turns through dusk into darkness.
From time to time, however, along comes a heavenly spectacle that’s all but impossible not to notice. Such a display is on tap for Monday evening just after sunset.
I’m sure many readers have seen the two bright “stars” hanging low in the southwestern sky the past several nights. Those “stars” are, in fact, our neighboring planets Venus and Jupiter. On the first of December this pair of sparkling jewels will be joined by a thin sliver of silvery moon.
When that tiny crescent of moon appears, take a closer look. Go ahead. Look long and hard and see if you can’t make out the faint bluish face of the rest of the moon’s surface that is not bathed in sunlight. See it?
That wan, bluish glow is called Earth shine. As we all should have learned in 3rd-grade science, objects like planets and their moons emit no light of their own but rather reflect light from the sun. Earth shine can be quite spectacular, depending on the degree of cloud cover at any given time, as photographs taken by astronauts from the surface of our moon attest. So what you are seeing on the fainter side of a crescent moon is sunlight reflected off Earth reflecting back to us from the moon.
And did you know that moon phases and Earth phases are in sync in what astronomers call complementary phases? We just had a new moon Thursday evening with the dark side of the moon was turned fully toward us. At the same time Moon Critters would have been marveling at a brilliant full Earth.
Of course, our trio of heavenly hosts will not be anywhere near one another Monday night or any other night. They only appear to be approaching one another as seen from Earth. The moon will be roughly a quarter-million miles out. Venus, meanwhile, lies some 93.2 million miles distant, and giant Jupiter is a mind-boggling 540.3 million miles away and approaching the far side of the sun.
Such facts are for textbooks, though. One of my favorite pilgrimages, if you will, is to Brewster County, Texas, down in the Big Bend Country. Lie on your back after dark without a campfire or lantern, and open your eyes to the heaven above. It's not so much what you see as it is what you feel. For me it's a realization of being incredibly small and indescribably insignificant.