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A flock of fiery visitors from outer space

We think we know them, of course, because we can name them – meteors. In fact, we can get more particular and call these the “Perseids,” meteors that appear near mid-August of each year and seem to stream out of the wonderful double-cluster that occupies the gap between Perseus and Cassiopeia.

I counted nineteen bright ones this morning – three before I even got my pants on – and this was about a full day after the predicted peak of the shower. Slept in, did you? Oh ye of little faith! Of course, I would have preferred to do my Perseids watching on Tuesday morning. That’s when the shower was supposed to be at its maximum. But this morning was just about as good for me as last year’s maximum. That certainly drove home the point others have made - that it’s well worth looking for the Perseids at least a day before and day after – well, a night before and night after – the predicted peak. In fact, I saw a few stray shower members during morning observing sessions a week or more ago – but that’s pure luck.

I didn’t invite anyone out for this morning’s show for two reasons. First, the weather forecast was still iffy. The Clear Sky Clock had the sky free of clouds, but the transparency very poor for the best viewing time – between 2 am and 4 am. And besides, even if it was clear I wasn’t that confident the shower would be this could on the morning after.

I should stress, too, that mornings are the key for one obvious reason – that’s when the shower’s apparent radiant – the point in the sky where the meteors appear to be entering and fanning out from – is high up in the northeast. Look at some reasonable (from human stand points) viewing time such as 9 pm and you’re cutting off about half of the possible meteors you could see.

Still, on Tuesday night I did get up about 3 am and I did look out the upstairs deck door and I did see bright flashes in the sky – flashes of lightning. We went on to have about an hour of one of the worst thunder storms in recent years - at least for Driftway Observatory. This morning my viewing plans were much more casual. As I say, the Clear Sky Clock had not been encouraging, indicating these couple of prime hours would not be so prime. So still half asleep and sweat pants and sweat shirt in hand, I stepped out on the upstairs deck about 2:05 am and said to myself – yes – transparency is pretty horrible. Then bingo – there’s a bright Perseid, burning a trial through the murk towards the Pleiades. Wow! Not bad. Probably the only one I would see.

I looked around. Yep. Conditions are terrible. I can see just three stars in the Little Dipper. About the dimmest star I can see was third magnitude. Whiz! There’s goes a second bright Perseid. I kept looking up. Zing – that makes three – and in less than five minutes. That’s pretty good. I put on my pants and sweat shirt, sat down in a damp chair and sure enough,. here’s a fourth. This is a real shower, I thought. But the fifth one was a long time coming and I finally broke my gaze long enough to put on my socks. Now it starts to look like the Clear Sky Clock was off a bit. In just 10 minutes – about two hours ahead of schedule – the transparency is improving. (OK – my night vision might have been improving a bit too, but usually it’s pretty good right away when I’ve been sleeping in a dark room.

I stayed out for about twenty minutes and came away with five Perseids. Not bad. Time to make some tea, get a coat, and head for the Observing Deck where I have a proper – and dry - rotating beach chair that allows me to back comfortably. Besides, if it were really clearing, I could do some prowling around familiar objects such as M31 with the 15-inch.

So I did that. I uncovered the big scope, grabbed my best eyepieces, and prowled about. The Telrad was pretty foggy, but with the 22mm Nagler in place I had a fairly large field of view, so it wasn’t much trouble to find the Double Cluster and the Andromeda Galaxy. Actually, I stumbled across it’s companion. M32. first. But the view just convinced me that I really prefer the view I had last week in a small refractor. Mind you, M32 and M110 are much more impressive in the 15-inch, but to get the full emotional impact of M31 you need a really wide field. It was more appealing to me this morning as seen in the 12X36 IS Canon’s – really. On a whim I pointed the 15-inch low in the northwestern sky – my most light-polluted quadrant - and looked for the Double Double. Again, I prefer the view in the smaller refractor. Oh, it split comfortably in the 15-inch – especially with the 7mm Nagler (about 241X) and to split it at all when it is this low in the sky is good. But the view was, in a word, sloppy. I’ve just gotten hooked on the pristine, high-contrast images of a good, small refractor.

As I aimed the scope at the Double Double, however, I did see another Perseid. This was number 7 and a real beauty, streaking down towards Lyra. And it made the point that Perseids can appear anywhere in the sky. Yes, they appear to radiate from one point – but their trails go back towards the radiant – doesn’t means they reach anywhere near it – just that they point in that direction. So figure if I saw 19 bright Perseids – and maybe glimpsed a half dozen others – that what I actually saw was probably less than half of what was visible during the time I was looking. That is, I can really see at most about one quarter of the sky at any given instant and some of that is blocked by trees, bushes, telescope, fence, etc. Also, I had perhaps a solid hour of seriously looking up – though I didn’t time myself. I doubt it was much more than that – so 19 bright meteors in an hour means one every few minutes. Of course they don’t arrive like that. They seem to come in burst with long periods of nothing.

Nothing can try your patience, but the “nothing” this morning included a Milky Way that stretched from Cygnus, low in the Northwest, to Orion rising in the Southeast. That gave a great sense of the plane of our galaxy, certainly worth contemplating any time. Quite a jump there, really, when you think about it.

Let’s see – we have Andromeda and friends beaming in from roughly 3 million light years. (The distance is still disputed.) Then we have the edges of our own galaxy mapped out in the Milky Way. And in an around it I roamed about with the 12X36 binoculars, pausing at the Double Cluster in Perseus, as mentioned, but also the familiar trio in Auriga – M37, 36 and 38 – all easily picked up,as was the fog of billions of stars in another nearby galaxy, M33. The clusters range from roughly 2,000 to 8,000 light years away. Closer to home were the familiar Pleiades at 400 light years – and always demanding some of my observing time. And then, through the branches of the mimosa I could see the Hyades with their “house” asterism, rising from just 150 light years away.
But the real show was much closer and several bright streaks brought out involuntary oohs and ahhs that I shared with the owls, rabbits, and other night creatures. There was a great one – number 15 I think – that stuttered it’s way towards the Hyades and seemed to be the slowest of the night. And the brightest – about magnitude -2 – was over near the northern horizon, well below the Little Dipper. And distance?

Well, these tiny visitors from outer space were pebbles at best – about the size of an eraser on the end of a pencil. Mull that over a bit. Not much. Certainly not what we’re used to contemplating in terms of astronomical objects. And what I could see of them was taking place pretty locally = perhaps 50 miles over my head.

Yet these tiny visitors from outer space were roaring in om us and running smack into air molecules in our upper atmosphere and those collisions were so violent that they parts of them started to ionize and emit light waves that were so bright I could see them outshining the stars, though they were 50 miles away. I mean, what do you think your flashlight would look like from 50 miles?

I know some folks are fond of miracles. They keep looking for a break in the natural laws. I consider the natural laws the miracle – and when I really think about what it means to see a meteor – what you are actually witnessing in that streak of light – well, a few ooos and ahhhs just don’t do it justice!


Posted by Greg Stone at August 13, 2008 06:10 AM Comments? Please email me: gstone@umassd.edu

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