No matter where you are in the world today, if you have a chance to look up in clear skies at the moon tonight, you’ll notice a bright star nearby it. That’s the Planet Jupiter. (moku-sei or 木星 in Japanese).
Almost due South at around 6:30 pm here.
If you live in a metropolis or other urban mass, chances are light pollution wipes out most of the evening sky. Light pollution comes from the tens of thousands of outdoor lights that are pointed upward as well as down. The upward lighting is useless—but most jurisdictions do not regulate against it.
Here in Tokyo, most of the stars you see on this 1999 version of “The Sky” software are a wash—you don’t get to see them. But you can see the moon and Jupiter. In the snapshot, it’s the yellow dot below the moon. The green one to the left of the moon is Neptune, which you can’t see without a telescope.
The line running through the screen shot is the apparent path of the sun, the ecliptic. As the earth moves around the sun, the sun blocks out different constellations with its brightness. So astronomers for thousands of years have tracked this line across the heavens. Because the whole solar system, in the end, revolves around the sun, all the planets and our moon don’t stray too far from this line.
I like the ten-year-old software, by the way, compared to the newer stuff, because it’s more pure. It is someone’s mathematical formula of where the heavenly bodies are supposed to be, with just enough graphics added on. Not too many bells and whistles. Like an old car dashboard. Something that isn’t overwhelming.
Jupiter is in orbit around the sun. It takes about 12 years. So each year, about, it spends time in one constellation. Now it’s in Capricorn. Next year around this time it should have made its way to Aquarius.
The moon is traveling around us, and does so in about 29 days. So it has to move fast through the zodiac—maybe only 2 or 3 days in each.
When Jupiter is visible in the night sky, the moon will pass by it once a month. It’s neat. For generations, this was the only show in town, and so people looked up and watched. Nowadays, modern technology washes out most of the marvel.
I think mankind made more great leaps in discovery when we used to have the large universe to wonder about at night.