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What Are the Draconids? A Brief History

2011 Perseid+Jupiter 600x515 What Are the Draconids? A Brief History

2011 Perseid+Jupiter Credit: David Dickinsen

Sure, you’ve heard of the August Perseids that come blazing across the sky and are invariably trumpeted by the news as the “Meteor Shower of the Millennium!” on a yearly basis. Perhaps you’ve even heard of the Leonids, normally a feeble November shower prone to legendary outbursts roughly every 33 years. But have you ever heard of the October Draconids?

I’ll admit I hadn’t until the October 1998 issue of Sky & Telescope arrived on my doorstep. Or should I say tent-flap? You see, the last half of 1998 found me deployed with my U.S. Air Force squadron to Al Jaber, Kuwait. In those days, email (and spam) were still a hip “new thing,” giant washing-machine-like CRT monitors adorned many office desks, and we were involved with a cat-and-mouse game between Saddam and the U.N. Inspectors that eventually became the shooting war of Operation Desert Fox. A military base in the desert was also a fine place to do some causal astronomy. The Leonids put on a fine show that year approaching storm levels of 1,000 per hour from our longitude. I remember mentioning the Leonid meteors to one of our F-16 pilots, and they later briefed not to mistake the fireball flashes for Iraqi AAA (an important distinction!) Read the rest of this entry »

Scopeless not hopeless

A blog for us AMATEUR amateur astronomers. By @RadioVicky.

Bio:

I’m 33, I live in Bristol and I like astronomy.  However, I don’t have a telescope and even if you did give me one, I’d be uncertain where to put my eye. I write comedy and I’m a professional blogger. My favourite colours are beer and dark skies.

Telescopes scare me. Not in the way a stranger in my bedroom or a spider in my knickers would scare me, but they do fill me with a certain fear.

I mean, I absolutely love things that go *shine* in the night, and have since I was a little girl, but the prospect of going out and buying a scope – something I know NOTHING about — is fairly petrifying. It even makes me feel a bit of a fraud. How can I be in to astronomy when I don’t even know my azimuth from my elbow? And also, I’m not too hot on my constellations either – sure, I know the main ones they teach you at school, but ask me to point out Lyra? Pegasus? Lucky Jim’s Pirate Ship?

OK, I admit it, I’m an AMATEUR amateur astronomer, but so is 99.9999999999999999999999% (possibly more nines than that, I didn’t have time to conduct a survey) of the world’s population, so it’s a cool club to be in.

Old Edwin1 546x600 Scopeless not hopeless

Before I got friendly with astronomers on Twitter, I always fancied one of those thin tubular ones they sell for £90 in Argos. Surely I would be able to see the storms on Jupiter, the arms of Andromeda, and the Bristol football team practicing from 10 miles away? Turns out I’d be better off peering through a toilet roll tube with some cling film on the end of it – I’ve been told that cheap telescopes merely turn unimpressive white dots into marginally less impressive WOBBLY white dots, so I’m saving the cash for a Virgin Galactic space holiday instead. I hear the weather’s quite exceptional on Mercury…

But something happened this weekend that made me feel better about scope envy. I’ve been getting friendly with our very own @virtualastro on Twitter, and when I discovered I had 900 free minutes to use before the end of the month, I thought it was nigh on time we spoke to each other.

So, I called him up, and we spent a total of FIVE HOURS on the phone over the course of Saturday and Sunday night. Rest assured Twitter, we have plotted and planned some very exciting things together which will be blazing your way like a comet made of ideas instead of muddy ice soon …but the best, most wonderful, amazing, magical thing we did was…GO STAR HOPPING TOGETHER. Without a freakin’ telescope!

Even though we are about 70 miles apart (I live in Bristol, he lives in Oxfordish somewhere) we were both able to look up at the same sky, see the same ISS passes, and the same meteors. It was remarkable to be on the phone to someone with such an incredible knowledge of the skies. I sat gob smacked, mouth and ears open, as he talked me through constellations, clusters, satellites and gory Greek myths. I had no idea Cassiopeia had been a naughty girl and was sentenced to dangle upside down on a chair for eternity. I’d never heard of the Cygnus Rift — an ominously dark patch of sky in our milky way. I couldn’t even pick out the summer triangle, but now I know where it lives I will undoubtedly point it out to people in the pub, spilling cider as I leap around, trying to remember which stars make it up.

The best part was a dazzling ISS pass with a Perseid meteor streaking past like an arrow through a love heart. @VirtualAstro even had to put the phone down to deal with the deluge of tweets, and it felt amazing to be part of something so communal, so magical, yet so fleeting.

He also reassured me I didn’t need a telescope to enjoy the skies – which is fabulous because I was getting a bit sick of wishing for one on every meteor I saw. He said ‘if you look up at the sky…then you’re already an astronomer,’ a line which neatly castrated the last traces of my scope envy.

As I lay back and looked at the star-flecked sky, with crickets singing in the hedge, and Adrian firing me up with a guided tour of our resplendent heavens, it dawned on me. This was better than any naughty phone chat line. He could quite easily wire up a premium-rate number to his phone and charge £1.50 a minute for the pleasure of his knowledge.

Yep, I had a great time star-gazing without a scope last night. To the point of rubbing my thighs and drooling a bit. And how was it for you, darling?

200603 71 Scopeless not hopeless

Vicky pretended she was having fun looking through the telescope, but the view was better with just her eyes.

 

The Perseids – The Most Reliable Meteor Shower Of The Year

Originally posted on Dark Sky Diary as “Perseids Meteor Shower 2011″ by Steve Owens @darkskyman on twitter

This month sees the most reliable meteor shower of the year; the Perseids. You can begin watching for Perseid meteors now, and the shower will last until mid-August, but the peak of the shower occurs in the small hours of Saturday 13 August 2011.

 The Perseids   The Most Reliable Meteor Shower Of The YearPerseus under dark skies
 The Perseids   The Most Reliable Meteor Shower Of The YearPerseus under moonlit skies

Unfortunately this year’s shower will be obscured by the full Moon which occurs on the same day, and so it won’t present its usual excellent display.

The number of meteors that you will observe every hour depends on a number of factors:

  • the density of the cloud of dust that the Earth is moving through, that is causing the shower in the first place;
  • the height above the horizon of the radiant of the shower, the point from which the meteors appear to radiate;
  • the fraction of your sky that is obscured by cloud;
  • the naked-eye limiting magnitude of the sky, that is a measure of the faintest object you can see.

Please visit Dark Sky Diary for the rest of this article………..

The Great Perseid Meteorwatch

Thursday 11th to Sunday 14th of August 2011

From Thursday 11th to Saturday 13th of August 2011 @VirtualAstro on Twitter with the help of The National Trust, Universe Today, Royal Astronomical Society and many more, will be holding a Twitter Meteorwatch for the Perseid Meteor Shower.

Everyone is welcome to join in, whether they are an astronomer, have a slight interest in the night sky or just wonder?

As well as looking up, enjoying the night sky with us and seeing meteors, maybe for the first time? You will have the opportunity to contribute for fun with images and online, or to Science if you wish, by tweeting and seeing your results on a map, or by submitting Observing Forms if you are a more serious observer.

This event follows on from the popular Twitter Meteorwatch held in August and December of 2009 and 2010 “Meteorwatch 2009″

Use the hash tag: #Meteorwatch and get involved, ask questions, do some science, follow the event and enjoy the wonders of the night sky with us. Images and other information will be tweeted as it happens. Live!

Join in on Twitter, Facebook and Google+

The highlight of the summer meteor showers: The Perseids reach maximum around the 12th/ 13th of August and may put on a display of approximately 80 to 100 meteors per hour under ideal viewing conditions.

Conditions this year aren’t ideal due to there being a full moon, but the brighter meteors will be seen. Let’s hope the skies stay clear.

Perseid meteors are often bright with persistent trails which can linger for a while after the meteor has burned up. Further information on the Perseid meteor shower and how to view it, can be found here.

While you are looking for meteors, there will be other objects to look out for such as the Planet Jupiter late in the evening, the Milky Way, Summer Triangle, manmade Satellites and more.

The Twitter Meteorwatch will start at 21.00 BST on the 11th of August and will continue through to the evening of the 13th. Amateur and professional astronomers and stargazers from the US and other countries are invited to join in and take over from the UK, when the sun comes up here, helping make the event run continuously and be truly international.

Watch the awesome new trailer here….

 

End credits 600x337 The Great Perseid Meteorwatch

AstroParty

23rd to 30th of October 2011

In celebration of its 5th year, the Salisbury Star Party will be hosting AstroParty with 7 days of Astronomy activities for people of all levels of interest and ability. All are welcome and those who attend will enjoy dark skies, a fantastic location, great company and lots and lots of fun. The organisers intend to make the Astro Party one of the biggest and best astronomy events in 2011 and beyond.

Venue:

The event will be held in a lovely and spacious campsite in the pretty village of Sixpenny Handley in the glorious Wiltshire countryside, (an area of outstanding natural beauty) with dark skies and excellent facilities including a large cafe/ conference area.

The site is located within 300m of the Village High Street. There are a variety of shops, including General Stores/Newsagents, Butchers, Post Office, Gift Shop and also a Public House. The village church backs on to the campsite, which adds a little more of that country atmosphere to the venue.

The historic City of Salisbury and the market towns of Blandford Forum, Wimborne Minster, Shaftesbury and Ringwood are all easily reached within 30 minutes drive.

If you aren’t keen on camping, there are local B&B’s and hotels etc in the surrounding area.

Activities:

Star Party – Running for all of the 7 nights with around 70 to 100 experienced astronomers at its core, the Star Party is the main part of the event, so bring your kit if you have any, join in and take advantage of observing and imaging with a large group, whatever your level of experience? You don't even need to bring a telescope, just use your eyes.

Imaging World Record – More info coming soon?

Inflatable Planetarium Shows – Big planetariums with big shows all topped off with what’s up guides.

Talks – A daily program of talks by famous and experienced people in the world of astronomy.

Tweetup – A social gathering of social media. Twitter and Facebook users meet and tweet with your online friends here.

Tours of the Sky – live and real tours of the sky by experienced astronomers.

Telescope and Equipment Workshops – Ask for advice or get help with astronomical equipment.

Trade Stands – More info and who is coming soon?

Competitions – A raffle for that nice telescope or piece of imaging kit?

Hospitality – There will be a hog roast on the final Saturday, and there is a cafe which is open through the week. We hope to have additional tents where you can warm up, tweetup, get a coffee, have some soup, or somewhere to chill and drink your beer. There is a licensed bar on site and a pub in the village.

More activities and services will be added to the program before the event starts.

A website will be launched shortly where you can look for additional information and book your tickets for the event.

Please book tickets here 

Let’s Make AstroParty, hosted by the Salisbury Star Party one of the biggest and best astronomy events and we hope to see you all there.

5341157670 302f1097da AstroParty

 


The Moon Illusion

Originally posted on Dark Sky Diary by Sreve Owens @Darkskyman

I’ll make a prediction: on or around 19 March, when the so-called “Supermoon” occurs, at its closest approach to Earth in two decades, people will indeed report that the Moon looks much bigger than normal. But it won’t really be much bigger in the sky at all. It’s all in our heads!

 The Moon Illusion 

"Wow, the Moon's even bigger than that tree!"

You’ve probably all seen it before, a huge Full Moon sitting on the horizon. Time and again I have had people ask me why the Moon is so much bigger some times than others, and the answer is: it isn’t, really.

The Moon orbits the Earth in an elliptical orbit, meaning that it is not always the same distance from the Earth. The closest the Moon ever gets to Earth (called apogee) is 364,000km, and the furthest is ever gets (perigee) is around 406,000km (these figures vary, and in fact this Full Moon on 19 March 2011 will see a slightly closer approach of 357,000km).

So the percentage difference in distance between the average perigee and the average apogee is ~10%. That is, if the Full Moon occurs at perigee it can be up to 10% closer (and therefore larger) than if it occurred at apogee.

This is quite a significant difference, and so it is worth pointing out that the Moon does appear to be different sizes at different times throughout the year.

But that’s NOT what causes the Moon to look huge on the horizon. Such a measly 10% difference in size cannot account for the fact that people describe the Moon as “huge” when they see it low on the horizon.

What’s really causing the Moon to look huge on such occasions is the circuitry in your brain. It’s an optical illusion, so well known that it has its own name: the Moon Illusion.

If you measure the angular size of the Full Moon in the sky it varies between 36 arc minutes (0.6 degrees) at perigee, and 30 arc minutes (0.5 degrees) at apogee, but this difference will occur within a number of lunar orbits (months), not over the course of the night as the Moon rises. In fact if you measure the angular size of the Full Moon just after it rises, when it’s near the horizon, and then again hours later once it’s high in the sky, these two numbers are identical: it doesn’t change size at all.

So why does your brain think it has? There’s no clear consensus on this, but the two most reasonable explanations are as follows:

1. When the Moon is low on the horizon there are lots of objects (hills, houses, trees etc) against which you can compare its size. When it’s high in the sky it’s there in isolation. This might create something akin to the Ebbinghaus Illusion, where identically sized objects appear to be different sizes when placed in different surroundings.

 The Moon Illusion 

Ebbinghaus Illusion – the two orange circles are exactly the same size

2. When seen against nearer foreground objects which we know to be far away from us, our brain thinks something like this: “wow, that Moon is even further than those trees, and they’re really far away. And despite how far away it is, it still looks pretty big. That must mean the Moon is huge!”.

These two factors combine to fool our brains into “seeing” a larger Moon when it’s near the horizon compared with when its overhead, even when our eyes – and our instruments – see it as exactly the same size.

Supermoon Nonsense

Originally posted on Dark Sky Diary by Steve Owens @darkskyman

There seems to be a growing excitement about the “Supermoon” that is due to occur on 19 March 2011, when the Moon will be at its closest to Earth in this orbit, and closer than it has been at any time since 1992.

 Supermoon Nonsense

Moon – not Super

The Moon orbits the Earth in an elliptical orbit, i.e. it is not perfectly circular, and so in each orbit there is a closest approach, called “perigee” and a furthest approach, called “apogee”.

At this month’s perigee the Moon will be 356,577km away from Earth, and will indeed be at its closest in almost 20 years. But how close is it compared with other perigees?

Let’s start by comparing it to the Moon’s average distance from the Earth, which is ~385,000km. This perigee will be ~8% closer to the Earth than average. OK, that’s a bit closer, but not significantly so.

What about comparing it to the Moon’s average perigee distance, which is ~364,000km. So this “Supermoon” will be ~2% closer to the Earth than it is most months at perigee. Wow!

So what will this mean to you? Nothing at all. The Moon will be a few percent bigger in the sky, but your eye won’t really be able to tell the difference. It will also be a few percent brighter, but your eye will compensate for this too, so altogether this “Supermoon” will look exactly the same as it always does when it’s full.

As to all of those soothsayers claiming that there will be earthquakes and tidal waves. There very well might be, but they’ll be nothing at all to do with the Moon.

UPDATE: I predict that lots of people will report having seen a huge Moon on or around 19 March

Sark: The World’s First Dark Sky Island

Originally posted on Dark Sky Diaries by Steve Owens (@darkskyman on Twitter)

The Channel Island of Sark has been recognised for the quality of its night sky by the International Dark-sky Association (IDA), who have designated it the world’s first dark sky island, the latest in a select group of dark sky places around the world.

Sark has no public street lighting, there are no paved roads and cars, so it does not suffer from the effects light pollution in the same way as towns and cities do. This means that the night sky is very dark, with the Milky Way stretching from horizon to horizon, meteors streaking overhead, and thousand of stars on display.

 Sark: The World’s First Dark Sky Island

Caption: “Stargazers on Sark enjoy the wonder of the Milky Way”. Image Credit: Martin Morgan-Taylor

The announcement was hailed as a great success by astronomers. Prof Roger Davies, president of the Royal Astronomical Society, said: “This is a great achievement for Sark. People around the world are become increasingly fascinated by astronomy as we discover more about our universe, and the creation of the world’s first dark sky island in the British Isles can only help to increase that appetite. I hope this leads to many more people experiencing the wonders of a truly dark sky”.

The award follows a long process of community consultation, which included the assessment of the sky darkness and an audit of all the external lights on Sark. A comprehensive lighting management plan was created by lighting Jim Patterson of the Institute of Lighting Engineers, and many local residents and businesses have altered their lighting to make them more dark sky friendly, ensuring that as little light as possible spills upwards where it can drown out the starlight.

 Sark: The World’s First Dark Sky Island

Caption: “The Milky Way above the Seigneur’s Mill on Sark”. Image Credit: Martin Morgan-Taylor

The government of Sark, the Chief Pleas, were supportive from the start. Conseilleur Paul Williams, chair of the Agriculture Committee, which oversees environmental matters, said: “Sark becoming the world’s first dark sky island is a tremendous feather in our environmental cap, which can only enhance our appeal. Sark is a wonderful island and this recognition will bring our uniqueness and beauty to a wider audience.”

This designation means that Sark joins the select group of international sites chosen for their dark skies, including Galloway Forest Dark Sky Park, which became Europe’s first International Dark Sky Park in November 2009.

Steve Owens, the dark sky development officer who led Sark’s application to the IDA, recognises the benefits that this might have for the community on Sark: “This is an ideal opportunity to bring stargazers to the island throughout the year, and I think that Sark is about to see a boom in astro-tourism, especially in the winter months. We’ve seen a surge of public interest in astronomy in recent years, with the International Year of Astronomy in 2009 and more recently with the success of BBC Stargazing Live, and it’s great that places like Sark and Galloway Forest Dark Sky Park are allowing people from towns and cities to come and experience a dark sky”.

FURTHER INFORMATION

Sark Tourism: http://sark.info/

International Dark-sky association: http://www.darksky.org/

Campaign for Dark Skies: http://www.britastro.org/dark-skies/

Star Counting

The Campaign to Protect Rural England (CPRE), in conjunction with the British Astronomical Association‘s Campaign for Dark Skies, has recently announced their 2011 Star Count Project.

 Star Counting

Star Count Week 2011 (from CPRE website)

Star Count Week (Monday 31 January – Sunday 06 February 2011) aims to get you outside and looking up, specifically to assess how dark – or light – your sky is.

The technique is simple. 1. Find Orion. 2. Count all the stars you can see within the main rectangle formed by Betelgeuse, Bellatrix, Rigel and Saiph, the four stars that make up Orion’s shoulders and feet. (Don’t count the three bright belt stars). 3. Tell the CPRE.

That’s it. By counting how many you can see, astronomers can calculate your sky’s limiting magnitude, or the brightness of the faintest stars you can see. It’s a very simple – and rewarding – project to take part in.

There are other annual star count programmes, such as GLOBE at Night (March 22 – April 4 2011) which I blogged about during their 2010 event. You can also get more involved and conduct a detailed dark sky survey, or take part in local activities such as the Peak District National Park’s Orion in the Peak project

Meteor Showers for 2011-2012: Ones to watch

Originally posted on Dark Sky Diaries by Steve Owens (@darkskyman on Twitter)

With the Quadrantids meteor shower that has just past yielding around 100 meteors per hour in near-perfect New Moon conditions, which showers of the next two years will give us as good a display?

 Meteor Showers for 2011 2012: Ones to watch

Meteor Shower

There are a few regular, dependable showers that can be relied on to put on a good show year after year, given a good Moon phases, so let’s concentrate on those:

Lyrids 2011
The Lyrids peak this year on April 21/22, only three days after the Full Moon, making conditions far from ideal. The ZHR is around 20, but under bright Moon conditions this will be much reduced, so that from the UK you might only see a few Lyrids per hour.

Persieds 2011
The Perseids peak on 12/13 August 2011 coincides exactly with a Full Moon, making this shower pretty much a write-off in 2011.

Orionids 2011
The Orionids peak occurs on 21/22 October 2011 just after the last quarter Moon, with the Moon rising a little after midnight, just as the meteor shower radiant is gaining height. Again, far from ideal.

Leonids 2011
The Leonids peak on 17/18 November occurs during a last quarter Moon, which unfortunately is smack bang in the direction of Leo, and so will obscure many of the Leonids in 2011

Geminids 2011
The Geminids peak on 13/14 December 2011 will likewise be completely obscured by an almost-full Moon in Gemini.

Quadrantids 2012
The Quadrantids peak on 3/4 January 2012 will feature a waxing gibbous Moon which won’t set until 0400.

Lyrids 2012
The Lyrids peak on 21/22 April 2012 is the first major shower peak in 15 months where the Moon is absent, meaning that you should get good views of this shower which has a ZHR of only around 20.

Persieds 2012
The Perseids peak of 12/13 August 2012 will feature a thin waning crescent moon that’s visible in the sky from midnight, obscuring some of the Perseids.

Orionids 2012
The Orionids peak on 21/22 October 2012 is pretty much Moon-free from around 2330, as the Moon sets.

Leonids 2012
The Leonids peak on 17/18 November 2012 will also be Moon free from early evening, and so presents an opportunity to see a few Leonids.

Geminids 2012
Rounding off this two year run of poor Moon conditions for meteor showers, we end with the Geminids on 13/14 December, coinciding wonderfully with a New Moon on 13 December, meaning conditions will be near perfect.