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Leonids Meteor Shower 2012

November 15, 2012 3 comments

One of the year’s regular meteor showers, the Leonids, happens this weekend, peaking at around 0930 on 17 November 2012. It (usually*) isn’t one of the very active showers (such as the Perseids, Geminids or Quadrantids), with the maximum rate in a normal year between 10-20 meteors per hour in perfect conditions.

The peak of the Leonids is quite broad, lasting several days, so between now and early next week it’s worth looking up to see if you can catch a glimpse of any shooting stars. The best time to view the Leonids shower is in the pre-dawn hours, but any time after 11pm on Thursday through to Tuesday night should mean you’ll see at least a few meteors.

How to see the Leonids Meteor Shower

1. Find somewhere dark with as little light pollution as possible. The countryside is best, but if you’re stuck in a city try and get away from as many lights as possible.
2. Bring a reclining deck chair. Standing outside looking up for long stretches of time gets uncomfortable.
3. Bring a blanket. It gets VERY cold outside at night in November.
4. Position yourself under your blanket on your reclining deck chair so that you take in as much of the sky as possible. Although the meteors all appear to radiate out of the constellation of Leo in the SE there’s no need to specifically face this direction as the meteors will streak across any part of the sky.
5. Wait. The rate of this shower isn’t very high, so you might only see one every five or ten minutes, maybe less often than that, so patience is a virtue.

* every 33 years the Leonids meteor shower turns into a meteor storm, in which the rates dramatically increase by a factor or 50 or more, up to perhaps several thousand meteors per hour. This regularity is due to the nature of the origin of the dust that causes these meteors. It comes from the tail of a comet, Comet Temple-Tuttle, which orbits the Sun once every 33 years. This means that the dust trail left behind by the comet – and subsequently hoovered up by the Earth to make a meteor shower at the same time every year – is refreshed every 33 years, resulting in a spike of activity for a few years afterward each pass of the comet. The comet last renewed the trail in 1998, and so the years 1999, 2001 and 2002 were all spectacular years for the Leonids, with storm rates peaking at 3000 Leonids per hour. I was lucky enough to see all of these showers, the most memorable being 2002 where in the space of just two hours under half-cloudy skies on the outskirts of Glasgow I saw over 300 shooting stars.

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Leonids Meteor Shower 2011

November 10, 2011 1 comment

On the night of 17/18 November 2011 the Leonids meteor shower reaches its peak. This annual performer is associated with Comet Temple-Tuttle, which orbits the Sun once every 33 years leaving a trail of debris as it goes. Once a year the Earth passes through this trail, and we see a meteor shower.

Leonids 2001

This year’s Leonids shower is hampered by the last quarter Moon which sits just to the right of the radiant of the Leonids, in Leo. Despite this there is good reason to observe the shower this year, as the International Meteor Organisation suggest there might be as many as three peaks of activity.

Throughout November the rate of Leonids will increase, with the main peak occurring at 0340 GMT on 18 November, at which time the Zenith Hourly Rate may be 20+. For observers in the UK, observing under cloudless skies, away from light pollution, this translates as an hourly rate of ~14, but the Moon will interfere and reduce this value somewhat. Two other peaks may also occur, at ~2100 on November 17, and at ~2300 on 18 November, with similar rates. This means that both the nights of 17/18 and 18/19 November may offer good opportunites to observe this shower.

The Leonids has the distinction of being the most dramatic meteor shower that I’ve ever seen, as I observed the Leonid meteor storms every year from 1998 to 2002, when we saw hundreds of meteors each night at the peak of the shower. These storm peaks are predictable, and occur every 33 years, associated with the pass of comet Temple Tuttle, as it refreshes the trail of debris that cause the meteors. The next pass of Temple Tuttle is due 2031, so we’ve a long wait for the next storm.

Interestingly, the Leonid storm of 1833 was truly stunning, with rates estimated to be around 100,000 per hour across North America.

To view the Leonids, find a dark spot, away from light pollution, sit on a reclining deck chair facing as large an area of the sky as you can manage, wrap yourself in a blanket, and enjoy the view. For observers in the UK the meteor shower radiant will rise around 2200 GMT on 17 November and will be high in the SE by 0400 on 18 November.

If you want to make observations of the Leonids that might help scientists better understand the shower, you can do so via the Society of Popular Astronomy, or the British Astronomical Association. Lots more info can be found at the Meteorwatch website.

Draconids Meteor Shower 2011

October 2, 2011 Leave a comment

On Saturday 8 October 2011 a rare event may occur – a meteor storm! The usually sedate Draconids meteor shower only produces a few shooting stars per hour in most years, but in some years we have a meteor storm, and that’s just what’s predicted for this year.

It won't look like this

During a meteor storm the Earth passes through a particularly dense clump of comet dust, meaning that rates of shooting stars temporarily spike, and estimates this time suggest the possibility of up to 10 shooting stars per minute during the peak of the storm. However a nearly full Moon will spoil the view, drowning out all but the brightest 10% of meteors, reducing the actual observed rate of perhaps 1 per minute – still well worth looking out for.

The peak is set to occur at 2000UT (2100 BST), and is ideally placed for observers in the UK. Activity is expected to increase from 1600UT (1700 BST) but at that stage the sky will still be bright in the UK.

If you’re keen to witness this (possibly) amazing event here are some top tips:

    1. Head out early. Start your meteorwatch once the sky gets dark enough. For most people in the UK this will be from 1900 – 1930 BST (anyone living in the north of Scotland will have to wait a bit longer). Although the peak of the storm is estimated to occur around 2100 BST there will be plenty to see in the hours leading up to the peak.
    2. Know where to look. The Draconids all appear to originate from the constellation Draco, which will be high in the NW sky, just above and to the left of the north star, Polaris. However the meteors will streak across the entire sky so don’t just look NW.
    3. Know what to look for. Meteors appear as bright streaks of light moving rapidly across the sky. They last for a fraction of a second, but the Draconids are unusually slow meteors. Still, blink and you might miss one.
    4. Keep the Moon to your back. The full Moon will drown out the light from all but the brightest Draconids, and if you look at the Moon it will spoil your night vision, so keep it behind you, ideally blocked out by a building or tree.
    5. You just need your eyes. Binoculars and telescopes, while ideal for observing faint nebulae and planets, are no good for meteorwatching. You want to take in as much of the sky as you can, and have as wide a field of view as possible, so just use your eyes.
    6. Get comfortable. The best bit of meteorwatching kit is a reclining lawn chair. Point it towards the NW, lie back, look up and enjoy the show.
    7. Keep warm. It will be very cold outside if it is clear, so wrap up warm. If you’re lying back on a reclining chair, wrap yourself in a blanket or sleeping bag form maximum warmth.
    8. Get away from city lights. This isn’t as important for this shower, as the Moon is flooding the sky with natural light anyway, but in general the fewer lights you have around you the better.
    9. Get away from clouds. This hopefully goes without saying, but if your sky is cloudy you won’t see much. The UK Met Office website can tell you if there is a clear sky anywhere near you, and you should consider traveling to get clear skies.
    10. Record your observations. If you want to take part in a meteorwatch and submit your observations there a several ways you can do that. One fun and accessible approach is to tweet your observations with the #meteorwatch hashtag. If you want to take more detailed rigourous data you can submit an observing form to the International Meteor Organisation, the British Astronomical Association or the Society for Popular Astronomy

Make sure you tell your friends! This a great opportunity to see a rare meteor storm, so get as many people as possible outside and looking up.

CAVEAT: This is only a predicted meteor storm; it may not occur and if it does not then meteor levels will be very low.

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