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Perseids
- albertw
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19 years 8 months ago #4126
by albertw
Albert White MSc FRAS
Chairperson, International Dark Sky Association - Irish Section
www.darksky.ie/
Perseids was created by albertw
[merging a few posts to have one thread here - Originals from Terry and Sean Morris]
Maximum of the Perseids meteor shower approaches, and conditions this year are very favourable, with no moonlight to worry about.
Some are already being seen each clear night, but the best is yet to come. They will increase in number each night for the next couple of days, reaching a maximum late on the night of 11/12 August, when up to 100 meteors per hour may be visible under good conditions!
This shower occurs when the Earth passes through the trail of particles given off by Comet Swift-Tuttle, named after its discoverers.
A meteor is just the fiery death of one of these particles, which we see as it burns away during its high speed impact with our upper atmosphere. Most are just the size of a sand grain, brighter ones can be as big as a grape seed or apple pip, and a really bright one would be only the size of a pea! So we don't see the particle itself, just the fiery trail as it burns away at a collision speed of about 60 miles per second!
The Perseids are always one of the best annual showers, and with conditions this year being particularly favourable, let's hope for clear skies. Some experts also think that activity will be unusually high this year, and we may also get an extra early burst of activity just as darkness falls on Wed 11th. This is expected as we may pass through a dense 'filament' of particles given off by the comet at its penultimate perihelion passage in 1862. This is predicted for 21.50 BST, so we might just get the end of it as the sky darkens.
Activity should be quite high on the nights of 10/11, 11/12, and 12/13 August, with best rates in the early hours of 12 August, and the possible early burst of activity early on the previous evening. Perseids can appear in any part of the sky, but if you trace their paths back they will appear to come from Northern Perseus, which will be rising in the North East in the early evenings, getting high up in the Southern part of the sky just before dawn. The radiant moves slowly across the sky during August, and on the night of maximum it lies not far from the 'Double Cluster' in Perseus, or about 5 degrees N of Alpha Persei.
You'll see most meteors by looking at an altitude of about 50 degrees, and about 45 degrees to either side of the radiant, on whichever side the sky appears darker. But to get a proper view you must get away from all light pollution. If there's a lot of artificial light nearby, you might see only about one tenth as many meteors as if you were out in a dark rural sky.
So, if it's clear next Wednesday night, or even the nights before and after, have a look at the sky for as long as you can, and see some of these tiny visitors from space end their lives in such a spectacular fashion!
The weather forcast for the night is still a bit vague, but it looks as though there should at least be clear spells. For more weather information visit
www.met.ie/forecasts/
www.bbc.co.uk/weather/5day.shtml?world=0031
www.wunderground.org/global/stations/03969.html
www.metcheck.com/48hrforecast.asp?lat=53&lon=-6&locationID=297
(most of the above are for Dublin, though other locations are selectable)
As always please send reports pictures etc. here.
For more detailed information on observing and recording observations please drop into the International Meteor Organisation website at www.imo.net/
Any clear night gives you the chance to catch a falling star. But not literally! Tiny pieces of dust and particles no bigger than sand rip through the Earth`s upper atmosphere at speeds exceeding 120,000 miles per hour. This speed, coupled with friction within the upper atmosphere, causes these particles to burn up, leaving behind it a brief fiery display, known as a Meteor.
Meteors are typically the stuff of legend. In ancient times, objects in the night sky conjured superstition and were associated with gods and religion. But the misunderstandings about meteors lasted longer than those of most celestial objects.
Meteorites (the pieces that make it to ground) were long ago thought to be cast down as gifts from angels. Others thought the gods were displaying their anger. As late as the 17th Century, many believed they fell from thunderstorms (they were nicknamed "thunderstones"). Many scientists were sceptical that stones could fall from the clouds or the heavens, and often they simply didn't believe the accounts of people who claimed to have seen such things.
In 1807, a fireball exploded over Connecticut in the United States, and several meteorites rained down. By then, the first handful of asteroids had been discovered, and a new theory emerged suggesting meteorites were broken bits off asteroids or other planets (a theory that still holds).
When Can We See Meteors
All year round, many meteors will fall from a particular points in the sky at different times, known as the radiants. Each time an extraordinary burst occurs it is called a meteor shower. Some last for a few days, others for weeks. They all have a peak when, in a period lasting only hours, sometimes hundreds will be seen around the world from the one radiant. The most common one in recent times is the Leonid Shower, which peaks on November 17th each year. The radiant is located within the constellation Leo. Between 2001 and 2003, this shower reached a 33 year peak where over 1,000 meteors per hour could bee seen. Unfortunately for us, the Irish weather was not in our favour each time.
And in December, both the Geminids (from Gemini) and the Orionids (from Orion) give bright displays for crisp winter nights. Indeed, during the winter months are the best time for viewing meteors, even the faint ones. The air is clean and clear, it gets dark quickly, and the constellations with these radiants are high in the sky. The only problem you will have is the shivering cold!
Cheers,
~Al
Maximum of the Perseids meteor shower approaches, and conditions this year are very favourable, with no moonlight to worry about.
Some are already being seen each clear night, but the best is yet to come. They will increase in number each night for the next couple of days, reaching a maximum late on the night of 11/12 August, when up to 100 meteors per hour may be visible under good conditions!
This shower occurs when the Earth passes through the trail of particles given off by Comet Swift-Tuttle, named after its discoverers.
A meteor is just the fiery death of one of these particles, which we see as it burns away during its high speed impact with our upper atmosphere. Most are just the size of a sand grain, brighter ones can be as big as a grape seed or apple pip, and a really bright one would be only the size of a pea! So we don't see the particle itself, just the fiery trail as it burns away at a collision speed of about 60 miles per second!
The Perseids are always one of the best annual showers, and with conditions this year being particularly favourable, let's hope for clear skies. Some experts also think that activity will be unusually high this year, and we may also get an extra early burst of activity just as darkness falls on Wed 11th. This is expected as we may pass through a dense 'filament' of particles given off by the comet at its penultimate perihelion passage in 1862. This is predicted for 21.50 BST, so we might just get the end of it as the sky darkens.
Activity should be quite high on the nights of 10/11, 11/12, and 12/13 August, with best rates in the early hours of 12 August, and the possible early burst of activity early on the previous evening. Perseids can appear in any part of the sky, but if you trace their paths back they will appear to come from Northern Perseus, which will be rising in the North East in the early evenings, getting high up in the Southern part of the sky just before dawn. The radiant moves slowly across the sky during August, and on the night of maximum it lies not far from the 'Double Cluster' in Perseus, or about 5 degrees N of Alpha Persei.
You'll see most meteors by looking at an altitude of about 50 degrees, and about 45 degrees to either side of the radiant, on whichever side the sky appears darker. But to get a proper view you must get away from all light pollution. If there's a lot of artificial light nearby, you might see only about one tenth as many meteors as if you were out in a dark rural sky.
So, if it's clear next Wednesday night, or even the nights before and after, have a look at the sky for as long as you can, and see some of these tiny visitors from space end their lives in such a spectacular fashion!
The weather forcast for the night is still a bit vague, but it looks as though there should at least be clear spells. For more weather information visit
www.met.ie/forecasts/
www.bbc.co.uk/weather/5day.shtml?world=0031
www.wunderground.org/global/stations/03969.html
www.metcheck.com/48hrforecast.asp?lat=53&lon=-6&locationID=297
(most of the above are for Dublin, though other locations are selectable)
As always please send reports pictures etc. here.
For more detailed information on observing and recording observations please drop into the International Meteor Organisation website at www.imo.net/
Any clear night gives you the chance to catch a falling star. But not literally! Tiny pieces of dust and particles no bigger than sand rip through the Earth`s upper atmosphere at speeds exceeding 120,000 miles per hour. This speed, coupled with friction within the upper atmosphere, causes these particles to burn up, leaving behind it a brief fiery display, known as a Meteor.
Meteors are typically the stuff of legend. In ancient times, objects in the night sky conjured superstition and were associated with gods and religion. But the misunderstandings about meteors lasted longer than those of most celestial objects.
Meteorites (the pieces that make it to ground) were long ago thought to be cast down as gifts from angels. Others thought the gods were displaying their anger. As late as the 17th Century, many believed they fell from thunderstorms (they were nicknamed "thunderstones"). Many scientists were sceptical that stones could fall from the clouds or the heavens, and often they simply didn't believe the accounts of people who claimed to have seen such things.
In 1807, a fireball exploded over Connecticut in the United States, and several meteorites rained down. By then, the first handful of asteroids had been discovered, and a new theory emerged suggesting meteorites were broken bits off asteroids or other planets (a theory that still holds).
When Can We See Meteors
All year round, many meteors will fall from a particular points in the sky at different times, known as the radiants. Each time an extraordinary burst occurs it is called a meteor shower. Some last for a few days, others for weeks. They all have a peak when, in a period lasting only hours, sometimes hundreds will be seen around the world from the one radiant. The most common one in recent times is the Leonid Shower, which peaks on November 17th each year. The radiant is located within the constellation Leo. Between 2001 and 2003, this shower reached a 33 year peak where over 1,000 meteors per hour could bee seen. Unfortunately for us, the Irish weather was not in our favour each time.
And in December, both the Geminids (from Gemini) and the Orionids (from Orion) give bright displays for crisp winter nights. Indeed, during the winter months are the best time for viewing meteors, even the faint ones. The air is clean and clear, it gets dark quickly, and the constellations with these radiants are high in the sky. The only problem you will have is the shivering cold!
Cheers,
~Al
Albert White MSc FRAS
Chairperson, International Dark Sky Association - Irish Section
www.darksky.ie/
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- jhonan
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19 years 8 months ago #4150
by jhonan
Everyone in Ireland buys Meade, and they all buy them from Lidl.
Replied by jhonan on topic Re: Perseids
That's a great summary - Thanks Al! (And Terry and Sean Morris) 
John.
John.
Everyone in Ireland buys Meade, and they all buy them from Lidl.
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