The Perseid meteor shower has been active for a few days now, and is predicted to peak @ 13:19 UT on August 13th.
In fact, NASA's dedicated All-sky Fireball Network picked up a number of fireball class Perseids last night.
This diagram from NASA shows their orbits.
Last night, NASA's All Sky Fireball Network detected 17 Venus-bright meteors. The orbits of the meteoroids, color-coded by velocity, are shown in
the diagram below. Earth's location is marked by a red starburst:
Blue orbits correspond mainly to Perseids. The Perseid meteor shower doesn't peak until August 12-13, but Earth is already in the outskirts of the
debris zone of the parent comet, 109P/Swift-Tuttle. By mid-August, rates could exceed 100 meteors per hour. The show, in other words, is just getting
Note that by " Venus-bright meteors" I think they meant to say "meteors that are at least as bright as Venus".
As the article says, the Perseids are caused by the debris left behind comet 109P/Swift-Tuttle, and we are just on the outskirts of that debris zone
right now. Most of the debris that hits our atmosphere and gives us Perseid meteors is actually very small, "sand grain" or smaller sized particles or
meteoroids to give them their correct name, but larger meteoroids are also scattered throughout, and even one around the size of a cherry would create
an impressive fireball.
There are slightly larger Perseid meteoroids too, but since they are made of very fragile material and hitting the atmosphere at an average speed of
around 61 km/s, they completely disintegrate long before they get close to the ground.
When to observe
The short answer is any time after the sun has set between now and mid-August, with the nights surrounding the 13th being best if you want to see the
The Long answer is - Perseid rates gradually build up over the course of the next couple of weeks, and the peak itself is drawn out compared to most
other annual meteor showers, so wherever you are you will have a chance to see relatively high rates, even if the peak occurs during the daytime where
Of course that is providing the weather cooperates, which it often does not when it comes to meteor shower peaks (at least where I am anyway!), but at
least with the Perseids it's possible to get fairly good rates in the nights leading up to, and after the peak thanks to "spread out over time" nature
of this shower..
Also, there is a visible increase in Perseid rates throughout the night, up till it starts becoming light due to the Perseid
radiant which is located in Perseus at the time of the peak having a higher
elevation above the horizon later on in the night.
The rates may be higher later on in the night, but it's still worth observing throughout the night on the peak night/nights, as the radiant has
already risen by the time the sun has set for mid-northern latitude observers in the Northern hemisphere.
Although the Perseids are not observed in as great numbers from the Southern hemisphere due to the low altitude of Perseus above the horizon, it would
still be a good opportunity to try and observe earth grazing Perseids during the peak.
To an observer located in the southern hemisphere, these would appear to shoot up from the northern horizon, or along the eastern/western horizons,
but always heading away from Perseus and southwards. Grazers, although infrequent are some of the most amazing and impressive meteors in my
How to observe
Finding a good site to observe from is the key to observing meteor showers. Ideally, you want to be as far away from any cities/towns/villages/any
source of light in general as possible, and have clear all-round views free from obstructions like trees, buildings, and hills all the way down to the
Take a sleeping bag (or two if you are in an exposed location) plus a camp bed or something else comfortable to put your sleeping bag on, and look
straight up. Perseids will be visible in all parts of the sky, and by looking more or less directly up, you'll catch many more Perseids than you would
if you tried observing while looking low down in the sky.
In the case of Southern hemisphere observers, you would want to be looking upwards but with a slight bias to the north, since that is the direction
where earth grazers will become visible.
As with most annual meteor showers, it helps to have patience since there can be lulls in activity, especially outside the peak nights.
Don't forget to look out for long lived persistent trains which brighter Perseids often leave
behind them, and if you have a camera, why not try to photograph them. The Perseids have a reputation for being rich in bright meteors and fireballs,
making them a good target for photographers. Even so, getting a good shot of one can be frustratingly elusive as I have come to see over the years,
but don't let that put you off trying. You never know what you might catch! See below for tips and links.
This great video covers almost everything, but I would argue on a few points that were mentioned:
1. It's usually better to be totally flat when observing meteors since you can catch meteors close to any horizon with your peripheral vision when
facing directly upwards.
2. If you live in a warm/tropical climate, you might get away with a blanket (or even less) to keep you warm, but I'd advise putting on multiple
layers of warm cloths, and jumping into a sleeping bag if you want to observe for any length of time if you live away from the equator. If you are too
warm (unlikely in most cases) then you can always remove a layer of cloths or two.
3. The camera exposure times he mentioned could be at the upper end of the scale if you have any light pollution at you're site and/or depending on
your equipment/settings/how you want your photo to appear. It's worth experimenting before hand, but if you are using fast lenses/high ISOs (which you
should be if you want to catch any meteors, although you may get lucky and catch a bright meteor anyway), exposures can be as short as 5 or 10
seconds. See links below for more info.
I neglected to include alternate predictions for this year's Perseid peak from Jérémie Vaubaillon, who's predictions suggest the peak may come a
slightly over 24 hrs earlier than the prediction I mentioned in my OP, ie on the morning of the 12th. Keep in mind all predictions are in UT
(Universal Time), which is the same as GMT, so you'll have to convert to your own time-zone if you are not in the same time zone as the UK.
So there is some uncertainty as to which set of predictions well be most accurate. My advice would be to hedge your bets and observe on the night of
the 11th/12th, and on the night of the 12th/13th if you want to try and catch the peak.
Unfortunately, the moon will be more of a problem if the peak arrives early. For example, on the 11th/12th the moon rises at roughly 23.40 UT, while
on the 12th/13th the moon rises at roughly 01.32 UT. Moonlight, as most of you will know, will make it harder to see fainter meteors, and you'll
want to try and keep it outside of your field of view as much as possible. Luckily the Perseid meteor stream is usually rich in bright members, and
the moon's interference is not as bad as it can be around the peak, so it should still be a good show.
The run-up to the peak night/nights won't be as favorable, since the moon rises earlier on in the night (an hour earlier each successive night away
from the peak), and will be high in the sky/bright for the majority of the night, and especially towards dawn, when Perseid rates are usually at their
Amateur astronomer Thomas Ashcraft caught a nice Perseid fireball disintegrating over New Mexico on the 2nd August.
Click here for a clip.
The movie's sound track comes from Ashcraft's dual-frequency meteor radar. It works like this: Radio signals from distant VHF transmitters
bounce off the meteor's ion trail. Ashcraft's antennas can pick up those reflections, which sound like ghostly echoes in the loudspeaker of his VHF
We had mixed luck this year. The pre-peak night (10th/11th) was clear, but we couldn't find any clear skies for the peak night. On the night that was
clear, we set up the cameras and got in a few hours observing till it started to cloud up a little just before dawn.
For a pre-peak night it wasn't bad. I wasn't really counting, but I'd estimate that I saw perhaps 50+ meteors in around 5 hours of observing,
including sporadics and members of other showers. That also includes 3 or 4 fireball class meteors, the best of which was not a Perseid but a
Here are some of the best images from that night.
Crop from the photo above.
Crop from the photo above.
My partner and I saw this fireball, which was the brightest Perseid of the night that was observed visually.
Crop from the photo above.
Besides Perseids, we also observed and captured lots of satellites and satellite flares like this unidentified flare below, which is a composite of
three separate exposures. I intend to post the rest in another thread when I have the time.
There weren't many bright Perseids that night, but we managed to catch the brightest one we saw. Just a shame that we were clouded out on the peak
night/nights (the peak was a bit more prolonged than expected) or I'm sure we would have caught lots more.
If anyone out there missed out this year, don't fret - it looks like there are more favorable Perseid peaks in the years to come, and possibly even
an outburst or two. In the mean time, the Geminid meteor shower (which is usually
stronger than the Perseids) is only a few months away.
It was a rather weak showing here in the NorthWest... I watched for 5 hours through the peak time and maybe saw 25 to 30 small ones. Last night I saw
two large ones that were really cool. I also seen the space station like 5 nights in a row...
Cool the way it flares thru the spectrum from green to white to orange to red. Gone in a moment. Been cruising the solar system for eons and zzzt in a
flash. I wonder how long that track is in the sky? I we assume a 20 km/s velocity (we really don't know), and a 100th of a second burn time, then the
math I don't know comes out to...
Good questions, and thanks for the comments/reply intrptr
Originally posted by intrptr
Cool the way it flares thru the spectrum from green to white to orange to red.
Yeah - that aspect of some meteors has always fascinated me. The same colour changes are actually often observed in meteors that have a high enough
velocity such as the Leonids, and the reasons behind it are quite well understood.
Originally posted by intrptr
Been cruising the solar system for eons and zzzt in a flash.
Probably not quite "eons", but computer models strongly suggest that many of the Perseids we see were ejected from comet 109P/Swift-Tuttle 100's
and in some cases a few thousand years ago.
Originally posted by intrptr
I wonder how long that track is in the sky? I we assume a 20 km/s velocity (we really don't know), and a 100th of a second burn time, then the math I
don't know comes out to...
It's not too hard to estimate since we know that Perseids are all traveling at more or less the same velocity, which is around the 60 km/s mark.
We also know that most Perseid meteors don't last more than 1 second, and in this case, since I observed the meteor in question, I can confidently
say that that particular Perseid lasted between 0.5 and 1 second.
So the track in the sky is probably somewhere around 30-60 km in length.
Keep in mind that the track is probably no where near parallel to the plane of the camera sensor, so perspective will make it look shorter than it
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