Night Sky: Don’t believe the hype

During the seventeenth through the nineteenth centuries, most ordinary folk knew the sky’s basics. The sun’s rising and setting points on the horizon, the moon’s nightly one-hour delay in when it would rise, the apparitions of the evening star, all carried a satisfying familiarity.

No longer. Ask any friend, “If you take a second look at the moon an hour after first seeing it, which way has it moved?” very few would correctly answer, “To the right.” So, it shouldn’t surprise us that the media routinely “gets it wrong” when it comes to “informing” us about supposed sky events.

One big trouble-prone area lies in celestial happenings that sound cool but are actually not worth anyone’s time or trouble. We are now in the midst of a couple of these, so today’s column is here to serve as a “don’t bother.”

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First up: eclipses. A total solar eclipse can make people weep, that’s how awesome it is. But the “total” part is important. Only during a solar totality do pink flames leap from the sun’s edge, and animals go crazy, and stars come out in the daytime. None of that happens during a partial solar eclipse, which can’t even be safely observed without eye protection. So if you want to be swept away, it’s totality or nothing.

But not with lunar eclipses, one of which happens this week. Here, totality isn’t particularly important because nothing special occurs during a lunar totality. Not a single strange phenomenon materializes. Indeed, the visually optimum view probably unfolds when the moon is roughly 95 percent eclipsed, because then a single brilliant white spot of sunlight illuminates the moon’s edge while the rest of the moon is an eerie red.

But sometimes the moon doesn’t even go into the earth’s main dark shadow. The eclipse is then neither total nor even partial. Instead it has ventured into our planet’s outer, skimpy, penumbral shadow. When that occurs, the full moon appears unchanged. You want your money back.

And that’s what’s happening not once, but four times this year!

During such an “event” not even the greatest astronomers could tell an eclipse was in progress. It’s visually a non-starter. Yet this year, there was just such a “partial penumbral lunar eclipse” on January 10. And next week on Friday, June 5. And yet another partial penumbral lunar eclipse a month from now, on July 5. And still another on November 30. That’s right. Four partial penumbral lunar eclipses in 2020. Pretty remarkable And yet, if you go out next Friday night around midnight or so, the Full Moon will look unchanged. You won’t be able to tell an eclipse is in progress. But because many almanacs and major newspapers don’t know about eclipses or are aware of the radically different types, they will run headlines: Don’t miss tonight’s lunar eclipse! It’s the kind of thing that’s been confusing people since the Moon was first discovered in 844 BC.

I’ve been so long-winded about non-eclipses, we’ve got room for just a few sentences about the other current non-event: meteor showers. We all like to see shooting stars rip across the sky. And while about six an hour appear every moonless night, especially after midnight, you get many more during a “shower.” But most meteor showers are skimpy, meaning you might see a couple of extra ones in an entire hour, which isn’t worth the trouble. Bright moonlight likely cuts the number down to zero. On the other hand, it’s definitely worthwhile to watch the Perseids on August 11, the Geminids on December 13, and, a few times a century, the Leonids on November 17-18. Then, you’d see dozens an hour.

But, especially when there’s a bright moon, the others are not worth the trouble. Yet the media routinely urges viewers, listeners, and readers to “Look up tonight!” So here’s the easy bottom line: There are no worthwhile showers from January through July. Meaning now. They’re all concentrated in the latter half of the year, August through early January.

Now you know about the biggest sky events that aren’t there. (And, just in case you wondered, no, the Moon was never discovered.)