From: TerryMoselaol.com
Date: Fri, 19 Nov 2004 15:21:38 EST
Subject: What meteors?, ISS
Hi all,
1. It's not often you get an email from me sent just before 7 a.m.! But I
happened to be awake & heard the 06.30 BBC Radio Ulster News describe a "Meteor
Storm" to be expected later tonight (Fri 19 Nov). Shortly after, one of the
presenters did an interview with a spokesman for the Royal Astronomical Society,
whose name I will omit, about the expected "storm". I was so perturbed at
this that I got up & sent out the email! (They ran the headline story again on
the main 7a.m. News.)
This was, I presume, based on a Press Release from the RAS, about the
possibility of some unusual 'late' Leonid meteor activity. As you all know the
Leonids come every November, usually around Nov 17. But various astronomers,
including Dr David Asher at Armagh, had predicted the possibility of some enhanced
activity on Nov 19/20, after the shower would normally have ended. So far so
good - David's record on such predictions is impeccable! But neither David, nor
any of his colleagues, described the possible level of activity as a storm! In
fact, the predicted level is only about 10 meteors per hour! That's not even a
decent normal annual shower level! Nor did they say it would be visible from
UK/Ireland - the best place to see it would be much further East. In fairness,
the RAS spokesman did refer to this.
But he did also say in the interview that there were two possible times to
see these 'storm' meteors from here - from 9.30 to 10 p.m., and around midnight.
It was the first of these that got my goat! The radiant will be WELL below
our horizon even at 10 p.m., so we wouldn't see anything! Even from far Eastern
England, the radiant won't have risen by 10 p.m. So there simply won't be any
Leonids visible from the UK at that time. And we in Ireland are furthest away
in the British Isles from even the remote possibility of seeing anything. If
someone from the RAS does not realise that, there's not much hope for
popularising astronomy!
It's loose, misleading statements like that which can get astronomers a bad
name among the public - somebody raises expectations, people go out and observe
and see nothing and get totally disillusioned, and don't pay any attention to
future, realistic, predictions.
Even at the second time mentioned, 'around midnight', the level of activity
would be barely above the normal background rate, and would not even be noticed
by the casual observer! At this time of year we get around 10 meteors per
hour from the sporadic background every night! Of course you'll only see that
rate from a very clear dark sky! And with the Leonid radiant so low, a nominal
rate of 10 Leonids per hour would translate to about 1-2 per hour actually
observable!
Anyway to call a possible maximum (ZHR) rate of 10 per hour a "meteor storm"
is grossly misleading! Perhaps the word "storm" originated with the BBC, but
it didn't sound like it! The accepted definition of a storm is at least 1000
meteors per hour, so 10 hardly qualifies!
And just to emphasise the difference, we do expect a really good meteor
shower (but not a storm) from the Geminids in December - best activity on the
night of 13/14 December when rates might reach 80 per hour - so I hope that this
'False Alarm' wll not put people off.
I'm glad to note that after I sent out my email this morning (which went to
all my media contacts), the BBC stopped running the story, so maybe it was
worth getting up so early!
To sum up: we just MIGHT see some slight activity from the Leonids, after the
shower would normally have ended, at around, or shortly after, midnight
tonight, but don't expect anything spectacular! In fact, the level of activity is
expected to be so low here that I hadn't even issued an alert about it.....
(More on the Geminids closer to the time, of course!)
2. However, to compensate for the lack of Leonids, we are currently being
favoured with the start of another series of evening passes of the ISS. As I'm
sure you know, it appears as a bright moving star, sometimes nearly as bright as
Jupiter, crossing the sky over a period of a few minutes, generally from West
to East. The times vary from night to night, but you can get up to date
predictions for your location from For example, there's a
good one at about 18.10 for Belfast on Saturday night: times in other areas
will vary by up to 10 minutes.
Clear Skies,
Terry Moseley
aol.com Date: Fri, 19 Nov 2004 15:21:38 EST Subject: What meteors?, ISS Hi all, 1. It's not often you get an email from me sent just before 7 a.m.! But I happened to be awake & heard the 06.30 BBC Radio Ulster News describe a "Meteor Storm" to be expected later tonight (Fri 19 Nov). Shortly after, one of the presenters did an interview with a spokesman for the Royal Astronomical Society, whose name I will omit, about the expected "storm". I was so perturbed at this that I got up & sent out the email! (They ran the headline story again on the main 7a.m. News.) This was, I presume, based on a Press Release from the RAS, about the possibility of some unusual 'late' Leonid meteor activity. As you all know the Leonids come every November, usually around Nov 17. But various astronomers, including Dr David Asher at Armagh, had predicted the possibility of some enhanced activity on Nov 19/20, after the shower would normally have ended. So far so good - David's record on such predictions is impeccable! But neither David, nor any of his colleagues, described the possible level of activity as a storm! In fact, the predicted level is only about 10 meteors per hour! That's not even a decent normal annual shower level! Nor did they say it would be visible from UK/Ireland - the best place to see it would be much further East. In fairness, the RAS spokesman did refer to this. But he did also say in the interview that there were two possible times to see these 'storm' meteors from here - from 9.30 to 10 p.m., and around midnight. It was the first of these that got my goat! The radiant will be WELL below our horizon even at 10 p.m., so we wouldn't see anything! Even from far Eastern England, the radiant won't have risen by 10 p.m. So there simply won't be any Leonids visible from the UK at that time. And we in Ireland are furthest away in the British Isles from even the remote possibility of seeing anything. If someone from the RAS does not realise that, there's not much hope for popularising astronomy! It's loose, misleading statements like that which can get astronomers a bad name among the public - somebody raises expectations, people go out and observe and see nothing and get totally disillusioned, and don't pay any attention to future, realistic, predictions. Even at the second time mentioned, 'around midnight', the level of activity would be barely above the normal background rate, and would not even be noticed by the casual observer! At this time of year we get around 10 meteors per hour from the sporadic background every night! Of course you'll only see that rate from a very clear dark sky! And with the Leonid radiant so low, a nominal rate of 10 Leonids per hour would translate to about 1-2 per hour actually observable! Anyway to call a possible maximum (ZHR) rate of 10 per hour a "meteor storm" is grossly misleading! Perhaps the word "storm" originated with the BBC, but it didn't sound like it! The accepted definition of a storm is at least 1000 meteors per hour, so 10 hardly qualifies! And just to emphasise the difference, we do expect a really good meteor shower (but not a storm) from the Geminids in December - best activity on the night of 13/14 December when rates might reach 80 per hour - so I hope that this 'False Alarm' wll not put people off. I'm glad to note that after I sent out my email this morning (which went to all my media contacts), the BBC stopped running the story, so maybe it was worth getting up so early! To sum up: we just MIGHT see some slight activity from the Leonids, after the shower would normally have ended, at around, or shortly after, midnight tonight, but don't expect anything spectacular! In fact, the level of activity is expected to be so low here that I hadn't even issued an alert about it..... (More on the Geminids closer to the time, of course!) 2. However, to compensate for the lack of Leonids, we are currently being favoured with the start of another series of evening passes of the ISS. As I'm sure you know, it appears as a bright moving star, sometimes nearly as bright as Jupiter, crossing the sky over a period of a few minutes, generally from West to East. The times vary from night to night, but you can get up to date predictions for your location from
