APOD: Perseid Meteors Over Ontario (2013 Aug 13)

[APOD Robot]

Perseid Meteors Over Ontario

Explanation: Where are all of these meteors coming from? In terms of direction on the sky, the pointed answer is the constellation of Perseus. That is why the meteor shower that peaked over the past few days is known as the Perseids -- the meteors all appear to come from a radiant toward Perseus. Three dimensionally, however, sand-sized debris expelled from Comet Swift-Tuttle follows a well-defined orbit about our Sun, and the part of the orbit that approaches Earth is superposed in front of the Perseus. Therefore, when Earth crosses this orbit, the radiant point of falling debris appears in Perseus. Pictured above, a composite of 13 early images from this year's Pereids meteor shower shows many bright meteors that streaked through the sky the night of August 11 near Oakland, Ontario, Canada.

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[Guest]

What a great picture! And I am always impressed with the APOD roll-overs. One nit about this roll-over, however: the constellations are great, for orientation, but the galaxies are just distractive.

[Indigo_Sunrise]

>snip<

but the galaxies are just distractive.

Yeah, because there are just so many of them in the image.....


This is a really nice image, but I'm wondering about the meteors in the image - how enhanced are they? I ask because there are several that look like they were just sort of drawn in. For instance, at about one or two o'clock above the Andromeda Galaxy, and then the one directly to the left: to me, both of those look like lines that were drawn in, as they don't appear to have tapered ends or one end larger than the other, as many meteors show when imaged. Were they so faint that 'extra enhancement' was needed?
I do understand the need for some image manipulation or enhancement, but how much was done on the meteors? I did poke around on the imager's site, but under the section 'Photo Details', there isn't a lot of information.

It's a great image, though - especially for those of us that have been clouded out this year!

[Ann]

Thanks for the annotation, geckzilla, and thanks for the galaxies. It is particularly interesting to compare the high surface brightness of the inner bulge of Andromeda with the low surface brightness of M33.

Thanks for pointing out M34, too! This is of course no galaxy but a cluster. The Double Cluster looks nice too, as does - obviously - the Pleiades.

It's a really nice picture. The Alpha Persei moving group stands out splendidly.

Ann

[Boomer12k]

Really nice picture....galaxies, and annotation and all....

:---[===] *

[geckzilla]

What a great picture! And I am always impressed with the APOD roll-overs. One nit about this roll-over, however: the constellations are great, for orientation, but the galaxies are just distractive.

I do always wonder what I should annotate and what I should just leave out. I personally find the galaxies to be interesting and I try to look for things which I might wonder what they are without annotation, especially putting myself in the shoes of someone not so familiar with the sky. When I was doing the annotation on the image at full size, the Triangulum galaxy did stand out a bit more than it does at the size and compression level of the APOD presentation. I probably would leave it out if I could revise it.

[henrystar]

Ouch! I didn't mean to be so critical! And I should have said "galaxies etc" - my point wasn't that they aren't interesting - in fact they are far more interesting than meteors are - but that they distract from the point of the picture-of-the-day. As a picture of a meteor shower, it is a gem! For teaching purposes on radiants of showers, it is ideal!

[geckzilla]

I welcome (almost) all criticism. No worries.

[Chris Peterson]

And I should have said "galaxies etc" - my point wasn't that they aren't interesting - in fact they are far more interesting than meteors are...

Hey! Speak for yourself! :)

[Adolfo Domínguez]

The meteor running under Triangulum goes toward Constellation Perseus and not in the opposite direction as I would expected. Is this ok?
All these annotations on the image are important for me; I'm just learning from all of you, guys.
I think the meteors not having the "normal" shape were not given enough exposition time to appear so.
Thanks!

[Chris Peterson]

The meteor running under Triangulum goes toward Constellation Perseus and not in the opposite direction as I would expected. Is this ok?
All these annotations on the image are important for me; I'm just learning from all of you, guys.
I think the meteors not having the "normal" shape were not given enough exposition time to appear so.
Thanks!

It's possible that isn't a Perseid. But it's also the case that you can't always tell for certain what direction a meteor is moving from a still image. Sometimes you get an inverted light curve, with high intensity at the start, slowly tapering off. Not as common with Perseids, but definitely possible.

One thing that might not be clear is that these meteors were collected over 4.5 hours. That means the radiant moved quite a bit, and explains why all the meteors don't converge on a point, but rather, on a line.

[Joe New]

Love this photo. Is there any way to save the annotated version in WinXP? I right-clicked it, but then when I moved my cursor into the "Save As" dialogue box, the annotation diappeared. I expect I'll have to save it without *using* the cursor, in order to avoid *becoming* a curser. Thanks!

[geckzilla]

Love this photo. Is there any way to save the annotated version in WinXP?

http://apod.nasa.gov/apod/image/1308/pe ... labels.jpg

[neufer]

[Anthony Barreiro]

This is a truly lovely picture, and I love the annotations. I forget things from one year to the next, and need to relearn them. I had forgotten about lovely little M34, so thanks for pointing it out.

I was camping with friends last week watching the perseids, the milky way, and our neighboring local group galaxies. It's always a pleasant surprise how easy it is to see deep sky objects in a dark sky, compared with my light polluted urban home. M33 was obvious in binoculars, but at home I can never see it against the brighter sky glow.

[Beyond]

I noticed some red in the explosion in the video. Rusty iron

[neufer]

I noticed some red in the explosion in the video. Rusty iron

[b][color=#FF4000][size=115]You can see it there, the red twisty worm at the upper left, across the glow of the Milky Way. Image credit: Randy Halverson.[/size][/color][/b]

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A meteor's lingering tale
By Phil Plait | October 2, 2011 11:44 am

<<Randy Halverson is a photographer who makes stunning time lapse videos of the night sky. He’s currently in the process of making a new video, and in one of the frames he happened to catch a bright meteor, a bit of cosmic fluff burning up as it rammed through our atmosphere. What’s neat about this particular incident is that the meteor left behind a glowing streak that lasted for over half an hour!

Technically, that’s called a persistent train, and it’s not actually smoke. As a meteoroid (the actual solid chunk of material) blasts through the air, it ionizes the gases, stripping electrons from their parent atoms. As the electrons slowly recombine with the atoms, they emit light — this is how neon signs glow, as well as giant star-forming nebulae in space. The upper-level winds blowing that high (upwards of 100 km) create the twisting, fantastic shapes in the train. The actual details of how this works in meteor trains are not well understood, mainly because they are so difficult to spot and study. It’s hard to point a telescope at a position in the sky when you don’t know where or when a meteor will pass through!

I’ll note it’s not really friction that causes a meteor to burn up. Most of the heating is due to the meteoroid’s hypersonic passage through air, which compresses the gas, heating it up violently. The heat melts the rock (or metal) in the meteoroid, which then blows off, leaving behind a train that fades rapidly. But the glow from the ionized gas takes much longer to decay, leaving the persistent train.>>

[Guest]

Hey, Indigo_Sunrise, sorry I didn't notice this on the internet until just now. Net time feel free to email me from my blog.
The images of the meteors are enhanced in both brightness and contrast. I would say the most enhancement would be about 15-20% bighter than they appeared in the RAW images. As NONE were just drawn in. I will say that all were "Cut" from there original image (overlaying them would have made a mess of the stars, leaving the stars in about 14 different locations due to field rotation.) The easiest and best way I've found to deal with that is to select just the meteor, then cut and past it in proper orientation to the main image.
Some of the abrupt stops or starts are likely due to the camera using 20 second exposures. 20 seconds can sometimes see the start, or the end of a streak.
I actually had about 10 other meteor streaks from that night that, once oriented would be outside the framing of the original photo, or behind the tree. Therefore I didn't use them as I try to keep it as "true to life" as I possibly can (if that's even possible considering it's a composite)

If there is any other questions feel free to email me
dvgzx2@gmail.com

>snip<

but the galaxies are just distractive.

Yeah, because there are just so many of them in the image.....


This is a really nice image, but I'm wondering about the meteors in the image - how enhanced are they? I ask because there are several that look like they were just sort of drawn in. For instance, at about one or two o'clock above the Andromeda Galaxy, and then the one directly to the left: to me, both of those look like lines that were drawn in, as they don't appear to have tapered ends or one end larger than the other, as many meteors show when imaged. Were they so faint that 'extra enhancement' was needed?
I do understand the need for some image manipulation or enhancement, but how much was done on the meteors? I did poke around on the imager's site, but under the section 'Photo Details', there isn't a lot of information.

It's a great image, though - especially for those of us that have been clouded out this year!