If you’ve never seen a meteor this is the week to see one. Many times a year the Earth passes through the debris trail of various comets. Each passage produces a short-lived meteor shower though most aren’t much to see. A few times a year the Earth encounters a major shower which produces enough meteors to be noticeable by anyone. This week marks one of those major showers as the Perseids meteor shower will be best seen on the morning of August 13.
The Perseids were produced as dust was ejected from the nucleus of Comet Swift-Tuttle, a Halley-type comet which orbits the Sun roughly once every 135 years. The comet was discovered independently by 2 American astronomers, Lewis A. Swift and Horace P. Tuttle, in 1862. Ancient records suggest the comet was actually first seen in 68 BC. In addition to 68 BC and 1862, the comet has been observed on 3 other occasions, most recently in 1992. During its next return in 2126, the comet will pass within 0.15 AU of Earth and become a brilliant naked eye object.
Though the Perseids will peak on August 12/13 they have been active and producing meteors for weeks now. Video observations compiled for the AKM/IMO Video Meteor Network by Sirko Molau (of which my cameras are members) find that the Perseids are active between July 13 and August 26. During most of this time the Earth was encountering dust released over the past ~15,000+ years. Most of this ancient dust never crosses the Earth’s orbit so Perseid rates remain low (at best 5-10 meteors per hour). This week we encounter dust released more recently, within the past 5,000 years. Since the comet’s orbit over the past few thousands of years has intersected the Earth’s, we will see a large increase in meteor rates this week.
The peak of this year’s Perseids is predicted to take place around August 13 at 3h20m UT (11:20 pm EDT, 8:20 pm PDT, 8:20 pm Tucson time) which is not a great time for us in Tucson. Still, the maximum is broad and can last for many hours. The last 2 years have also seen a number of spikes in activity on the night or 2 around the predicted peak. What this means is that high Perseids numbers can happen at any time even if tens of hours before or after the predicted peak. This year will see passage near a few older trails which may enhance the number of meteors by 5-10 per hour. Predictions by Jeremie Vaubaillon and Mikhail Maslov show encounters with dust trails produced in 441, 1479 and 1862.
So how can you observe the Perseids? The key is to get outside Thursday night/Friday morning. The reason these meteors are called the Perseids is because they appear to radiate (move out from) a point (called the radiant) in the constellation of Perseus. For most of the night Perseus is located low in the northeastern sky so most meteors should come from that direction. Late in the night the radiant will be located just north of overhead. Note, you don’t have to look directly at the radiant. Meteors will be visible all over the sky and it is usually best to look about 45-90 degrees away from the radiant.
Though the radiant will be visible for nearly the entire night it will be too low in the sky to produce high numbers of meteors until after midnight. The later in the night you observe, the greater the number of meteors. By 3 to 4 am, the radiant is well placed nearly overhead. The Stellarium star chart below shows the sky over Tucson at 4 am on Friday morning with the Perseid radiant (yellow star) nearly overhead.
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How many meteors can you see? This depends on a lot of variables. The peak rate for the Perseids is usually between 60 and 100 meteors per hour. But… that rate (called the zenithal hourly rate, or ZHR) is only valid from a very dark site (where stars down to magnitude 6.5 can be seen), within a few hours of maximum, and with the radiant directly overhead. In reality, very few of us will be watching the meteors under such perfect conditions. Instead, most of us will be observing a few hours from maximum with the radiant lower in the sky and under a light polluted sky.
Over the past 3 years, the Perseids have produced ZHRs of between 50 and 200 meteors per hour on the night of maximum (and sometimes even the night before) and it should be safe to expect ZHRs of 50 to 120 during this year’s shower. If you are observing from a dark site where the Milky Way is bright and easy to see, you should be able to detect 35-85 meteors per hour. Under moderate light pollution (like that found in most of Tucson), apparent rates will be lower with 15 to 40 being seen per hour. Even if you observe from the middle of heavily light polluted cities you will still see a handful of meteors per hour. Again, rates will be lower the earlier you observe during the night since the radiant will be lower in the sky.
To follow the latest observations and ZHR measurements, visit the International Meteor Organization’s Perseids 2010 ZHR Live page.
The best way to observe meteors is to find a spot with a clear view of the sky and no (or few) bright lights shining in your eyes. This means getting away from the glare of pesky streetlights and security lights. A lawn chair is the most comfortable way to relax and see the sky. For most of us the temperature will be warm but if you are further north or at altitude, dress warm. You may be surprised with how cold the early morning hours can be. Also be prepared for bugs. Even though the early morning in Tucson is nice and warm (maybe even too warm) I’ll be wearing longs pants and a long sleeve shirt to try to minimize mosquito bites.
The Transient Sky - Comets, Asteroids, Meteors 
Thanks for the astronomy lesson…I always enjoyed it in college – one of my favorite courses. We had the opportunity to see a meteor shower last year and we loved it. Reminds you that this world is so much bigger than us.
http://www.wutevs.wordpress.com
Make a wish!
Crystal
http://www.crystalspins.com
I have been trying to catch the Perseids for a number of years. I unfortunately have not been able to do so yet, as there’s always something stopping me…fog, ambient light, an evil alarm clock malfunction… I’ll try again this year. Appreciate the article!
Great post! We spotted about 5 in an hour on Aug 7 in the woods of Nova Scotia…looking forward to the peak on the 13th!
i spotted 9 on the night of the 9th around 10:30-11:00pm.
It seems it’s always cloudy or foggy when the Perseids come around, but when I have caught them, it’s been an amazing show. Honestly, if you’ve never seen a meteor shower, it’s worth the trouble of staying up late or getting up early.
Todd
http://toddpack.com
Perseids are definitely my favorite meteor shower. I am glad there are curious people who pay attention to and post reminders of stuff like this. Hard to believe there are those who have never seen a meteor, but perhaps harder to believe is that many people simply don’t care. Kudos to you for enlightening and inspiring others to pay attention to their surroundings.
That is really interesting, astronomy has always fasinated me. I know where i’ll be on the 13th! Thanks for the information.
Thank you so much for posting this information. I live just outside of Gainesville, Florida (University of Florida) and a stargazer myself. I’m fortunate enough to live rurally…Hence, deep darkness for crystal clear gazing at the beautiful sky full of magnificence…
Thanks for the information!
-Noor
http://noor724.wordpress.com/
🙂
saw a pretty big meteor over Ireland last week at about 1am. biggest i’ve ever seen. one of the coolest things i’ve seen in the night sky, second only to the endeavour launch last year. 😀
Excellent and well detailed post! I always try to catch the meteor showers but til now have never read about the actual comets. The fact that the Earth will be passing through trails that are hundreds and even a thousand plus years old fascinates me even more. Thank you!
I’m an amateur mathematician, in my future articles I plan on using a lot of astronomy as a source of analogy. The use of astronomy in mathematics is like when teachers use diagrams to give their students a clearer picture of complex problems.
Problem in understanding an equation? Look into the sky.
Thank you for this information. I’m a starting astronomer (though this is a hobby) and your posts help a LOT!
So much to learn, so much to do.
Good day sir and thank you again.
I love astronomy!! 😀
I look forward to the Perseids every year. I have a friend who’s birthday is August 13th, and she calls the Perseids her ‘birthday fireworks display’.
I always look forward to the Perseids in August! This year should be great.
How wonderful!
Sadly, I live in San Francisco and our heavy fog does not allow for viewing of such celestial splendors, but I lived at the beach in Los Cabos, Mexico for a year & stayed up one August night with my husband a few other beachcombers and was privy to the music of the spheres….
Absolutely glorious!
Perseids are definitely my favorite meteor shower
I live in California. When would you say is a good time to go outside to see the show? I need to make some serious wishes on these shooting stars.
I “seriously” hope that your “wishes” are granted by the keeper of the stars, and serendipitous affairs…
Great Post – I was wondering the other day when it was best to see them. Subject to cloud cover, we sometimes get a terrific display (we are in the Valencian mountains of Spain) – which can entertain us for hours. That said, all too often we forget to look!
I live near Cantoria, Spain. If only the big marble factory which lies to the North of us would just turn its lights off at night we should get an amazing view. Just think of all the electricity they would save as well. Unfortunately, I don’t think they will take too much notice of me telling them to stop the light pollution.
I know! We’re just along from you, in Tijola. Heading up to the countryside just above Cela for the spectacle tonight, though. Hope you get to see at least some of them! xxx
I am now in Toronto and am excited to find a “Sweet Spot” to view them this year.
We used to enjoy them from Topanga Canyon in the San Fernando Valley in So. Cal. *sigh* Miss Good Ole’ Cali.
Thank you for your post and for letting EVERYONE know about this Awesomeness 😉
Thank you! My 14-year-old son has been telling me about this for two weeks. He so wants to get up very early to watch. Hope he can drag himself out of bed as I’m sure it will be a cool show.
It will be 5.20pm where I am….argh, won’t be able to see them in the day.
Hi Envoy,
Don’t worry too much about the predicted time of maximum. For one this time can often be wrong by a few hours and two, the Perseids will be producing lots of meteors for hours before and after the maximum. If you go out to watch on Friday morning, or even Thursday morning, you’ll see plenty of Perseids (assuming your not observing from the middle of a large city, then you might see only a few per hour).
Thanks for writing,
– Carl
congratulations acquainted awaited return visit
Im outside of Gainesville, Fl and I saw about 15 around 5AM…I love astronomy!
Great Post! Well this seems like good news for all those people who needs to make tons of wishes.
Thanks for the Tucson info – what’s nice about living in Tucson is you can drive a short distance and see the milky way – so, when the meteor showers arrive, we jump in our car and head north to one of our favorite viewing spots – and I’m so glad it’s not a work night this year….
I moved to Tucson 17 years ago and was greeted with the monsoons and then the meteor shower watching both from my foothills backyard. I never miss the show and have fond memories of waking my children up in the middle of the night and taking them out for the viewing ! I’ll be up at 3 Am again this year and continue the day with a morning walk with my dogs (children have moved on).
There was a huge meteor that left a trail for about 15 seconds.. happened between 12:30 – 1:30am pacific time.. I saw it in California… does anyone know where I can find a video on the net on it? Did anyone else catch it too?
The night of August 12-13…