skytalk

Triskaidekaphobia alert!


Be very afraid: this Friday marks the first of two Friday the 13ths this year. The Epsilon Perseid Meteors are a real shower that will appear as more of a trickle. Night sky treats include Saturn and Venus by night; Jupiter and Mars by day.


September 9, 2013

[Dave Heller] Well if Triskets are indeed the preferred snack of Triskaidekaphobics, let’s crunch the number 13 with Derrick Pitts, chief astronomer at the Franklin Institute. Let’s see Derrick, today’s Monday, September 9 …

[Derrick Pitts] … and then come Friday, could be a problem.

I forget, why am I afraid of that number?

Well you’re supposed to be afraid of that number because 13 is one of those mystical numbers of which we’re supposed to have some fear or concern. Well, if we go back and look at the incidences of Friday the 13th, we’ll find that there were three of them last year.

Wow, it seems like an awful lot of Friday the 13th’s.

Well it is, it’s kind of unusual for that to happen. That kind of thing only happens 14 or 15 times per century. It’s much more typical to have one or two of those each year; in fact, there are two this year: one this month, this Friday coming up, and then again in December of this year. But two of them happen in 42 or 44 years of each century.

So they’re fairly common.

It is somewhat common — you could think of it as being that way. So for given all of that, if it really were such a difficult day, then many more of us would have a lot more problems on that particular day.

Well, Derrick, let’s move back to a safer date — namely tonight, and if you go outside you may or may not catch the Epsilon Perseid Meteors.

I’m guessing maybe not. And that’s because the Epsilon Perseid meteor shower is really not one of the most prominent meteor showers of the year. This particular shower is typically rated at about five meteors per hour. That’s the typical zenith rate. So if we had a group of about six people out arranged in a circle looking at all portions of the sky, over the course of an hour, all of us together might count an average of five per hour. The normal, standard background rate for meteors any clear night, anywhere on the planet, is ten per hour. So five doesn’t really do it. But, so why has this come to light? In this particular instance, the Epsilon Perseid meteor shower had an outburst a few years ago that was captured on video, and some are thinking perhaps there could be an outburst of these meteors again. But, we shouldn’t expect that it’s going to be anything near the Perseid meteor shower that we typically see in August or the Geminid meteor shower we see in December.

But this does bring to light something very, very interesting about our ability to gather information about arching topics through the internet. And it is that when we look at things like meteor showers, or a blue moon for example, or maybe something about the planet Mars appearing in a particular way in the sky every August, we tend to take the information provided by the internet as authoritative in one way or another. So the Epsilon Perseid meteor shower is an example of one of those meteor showers that someone might bring to the public in some large public form and say: “Wow! This is an incredible meteor shower, spectacular, nature’s fireworks in the sky!” And really, it hardly ever plays out that way. And so in some ways this is misleading. I think the blue moon episode of these past few weeks is a really good example of that where an image of a blue moon was shown on national television as evidence of there having been a blue moon. Well, a moon cannot look that way, so we can only surmise that it was faked somehow, some poor researcher dug it up, threw it up for review and someone said, “Yeah! Let’s go with THAT story!” And then it turns out it’s not really a blue moon at all, either literally or figuratively. So we have to be very careful about the information that we gather from the internet and how that’s delivered.


“So the Epsilon Perseid meteor shower is an example of one of those meteor showers that someone might bring to the public in some large public form and say: Wow! This is an incredible meteor shower, spectacular, nature’s fireworks in the sky! And really, it hardly ever plays out that way. And so in some ways this is misleading.”

Derrick Pitts

  • Maybe don’t listen to this guy: Man shares his excitement over the Epsilon Perseid meteor shower


Let the internet-buyer beware though — there’s no need to doubt the reliability if one goes to the Franklin Institute Thursday night.

Yes, that’s true. The second Thursday night of every month — that would be this Thursday — Night Skies at the Observatory provides and opportunity for people to come out and take a look through a big telescope and see what things look like. Now this is great for folks who are living in Center City, Philadelphia. However, if Thursday doesn’t work for you and you’re a little bit further out, you know the Delaware Valley Amateur Astronomers have a public Star Party this Saturday night at the Valley Forge Historical Park model airplane flying field. Delaware Valley Amateur Astronomers is a great group of amateurs that always comes out with great telescopes and they start their evening programming at 7:30 p.m. So check them out as well.

  • Night Skies at the Observatory at the Franklin Institute, Philadelphia

If the Epsilon Perseids are passe, then what planets are there to be seen?

You know in the evening sky, Saturn and Venus are still there. Saturn is creeping ever lower to the western horizon and Venus isn’t moving very much, but the two of them together can make quite a site. Venus being very bright and easy to identify might lead you a little bit further around the south, where you can find tiny Saturn. A pair of binoculars will help you. Not that Saturn is tiny, it appears in our sky often. But if the evening doesn’t work for you, we can still be Jupiter and Mars in the predawn sky and they are rising earlier and earlier every night, so they’re slowly backing their way into the late night sky. But, still available an hour, hour and half before sunrise, high in the east.



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