A space radar picked up the sounds of a meteor shower as it delighted skywatchers over the weekend.
What do meteors sounds like as they hit Earth’s atmosphere? From this recording made by the U.S. Air Force Space Surveillance Radar in Texas, the “pings” from the Perseid Meteor Shower sound rather alien! The radar station in Lake Kickapoo, Texas is part of United States Strategic Command’s (USSTRATCOM), which involves detecting, tracking, cataloging and identifying artificial objects orbiting Earth, such as both active and inactive satellites, spent rocket bodies, or fragments of debris from natural and man-made objects. Reportedly, the radar can detect objects as small as 10 cm (four inches) at heights up to 30,000 km.
A Perseid through the sky. Credit: Nahum Mendez Chazarra, Rojales, Spain. Click to see this image and more on Flickr
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We made a wish that our readers would send in their images of the Perseid Meteor Shower, and it came true! Despite a full Moon and clouds scattered around the world, we heard from many of you that you saw — and successfully imaged — the 2011 Perseids. Many of you took advantage of Universe Today’s new Flickr group, an easy way to have readers share their astrophotos with us. Above is a colorful image of a Perseid streaking through the sky by Nahum Mendez Chazarra, in Rojales, Spain.
Below, see an image take from up above the world so high: astronaut Ron Garan on board the International Space Station captured his view looking down at a Perseid streaking through sky!
'What a shooting star looks like from space," wrote ISS astronaut Ron Garan on Twitter. Click for larger versionFaint meteor. Credit: Andrei Juravle, Timisoara, Romania. Click for larger version on Flickr
This is another Flickr submission, from Andrei Juravle, Timisoara, Romania. Click to see this image and more from Andrei.
A Chicago meteor! Taken near downtown Chicago under a nearly full moon on August 12th 2011. Credit: Janet Branson. Click through for Flickr version.
Impressive! This image was taken in the light-filled skies of Chicago, Illinois by Janet Branson.
Paul Miller from San Diego, California took the following two very nice images from Mt. Laguna:
Bright Perseid. Credit: Paul MIller, San Diego, California. A Perseid meteor and much more! Credit: Paul MIller, San Diego, CaliforniaA Perseid meteor is caught on camera by the Canada-France-Hawaii Telescope's mounted low-light Cloudcam before dawn on the morning of August 12, 2011. Still frame cropped and edited by J. Major
Here’s one from our own Jason Major — kind of! He found the Perseid streaking through the sky on footage from the Canada-France-Hawaii Telescope’s mounted low-light Cloudcam, and created this image.
First meteor! Credit: Leonard Ellul Mercer, Malta, EU
How’s this for beginniner luck?! “Last night I captured my first ever Perseid image with Andromeda on its upper left,” said Leonard Ellul Mercer from Malta. “This is the first time I tried imaging meteors. Was just lucky even though there was a bright full moon overhead.”
Keep imaging, Leonard — nice shot!
Meteor, or something else? Credit: Michaela Knott.
“I took this on August 12, 2011 I’m not sure what it is,” wrote in Michaela Knott, “but I know it’s not a plane (which is what most of what shows up in my time lapse ends up being). This year I think I only saw 2 dozen or so meteors over two nights I went out looking.”
Shot with a Nikon D60, 28mm lens f2.8 10 sec exposure at the Frosty Drew Observatory in Charlestown RI, USA. “It was taken @ 9:42 EST, still pretty early in the evening,” Michaela said.
Timelapse, Perseids and stars on August 12, 2011.Credit: David Parmet. Click to see this image and more on Flickr.
Or you can “watch” a visual graph is with the Meteorscan Meteor Live View created at the Norman Lockyer observatory in Devon England
How do these work? Basically these transmitters are at a distance where they are beneath the horizon from the radio receivers perspective. If you tune into this far of transmitter all you would normally get is static as it is so far away and hidden, due to being below the horizon.
Credit: IMO
When a meteor strikes Earth’s atmosphere it decelerates rapidly. The friction created by the air causes the meteor to burn up at extremely high temperatures creating the white “shooting star” that we are all familiar with. This process also ionizes the air along the trail making it possible to reflect radio waves.
The reflected signals are picked up by the radio receiver and can be heard as pings or whistles. Data can also be displayed on a computer in the form of different types of graph.
Meteor Live View Credit: Adrian West
There will also be a live audio and video stream, along with a live “Stay Up All Night” chat about the Perseids with NASA astronomer Bill Cooke and his team from the Marshall Space Flight Center as they answer your questions about the Perseids via live Web chat. Join them on Friday, Aug. 12 at 11 p.m. EDT — 03:00 UTC GMT — then make plans to stay “up all night” until 5:00 a.m. EDT on Saturday, Aug. 13.
Of course, as we have mentioned before, you can join in with watching the Perseids with the rest of the world via Twitter and the #Meteorwatch hashtag. Even if you can’t see any meteors, you can see where other people are watching them with the Twitter Meteor Map
Check out all these fantastic and interesting meteor tools and hopefully you’ll have a chance to go out and enjoy the shower with your eyes when the sky clears.
It’s time for the Perseid Meteor Shower and you want to bag some meteors (shooting stars), but how? Maybe you just want to know where and what time to look, or perhaps you are having a Perseid party and you want everyone to have a great time.
If so, then please read on…
First, you don’t need a telescope or binoculars or any high tech equipment. You just need your own eyes and glasses if you wear them.
It’s a good idea to be away from bright lights and if possible have a red light torch or red flashlight, but most importantly try to get your eyes adapted to the dark.
Bright light will instantaneously ruin dark adaption so shining flashlights into faces is a big no-no and looking directly at the Moon isn’t going to help either. Position yourself so you don’t get the Moon in your view.
The Perseids don’t rain down out of the sky; they appear every few minutes and this year, you may only see the rarer bright ones and very bright fireballs due to the full Moon that will be up, and the glare it will unfortunately provide. But if you can get in a good position to avoid the glare, sit back and wait to see some meteors. This is totally worth the wait, but you need to be comfortable or you will give up, go indoors and not see any.
The best bet is to get a reclining garden chair or airbed or something similar to lay back and relax upon. Lots of people put those yard trampolines to very good use and use them as meteor observing platforms.
Dress warmly and cover yourself with blankets or a sleeping bag, August is a summer month, but it can get quite chilly at 1:00am and this will make you give up early too, so stay warm.
Have plenty of drinks and snacks ready so you can basically camp out and not have to keep on getting up, or doing things, because this is when you will, ironically, miss the best fireball of the evening.
Perseid fireball. Image Credit: Pierre Martin of Arnprior, Ontario, Canada.
Where do I look and what direction?
This is the most common question I hear people ask about meteor showers and the answer is very simple.
Follow the above comfort guidelines, look up and away from the Moon and fill your gaze with the sky.
Perseid meteors originate from a fixed point in the sky called the radiant, which is in the constellation of Perseus, however meteors will appear in any part of the sky. You can trace their paths back to the radiant.
After midnight, look towards the East/Northeast part of the your sky to find Perseus. To find it look for the easily identifiable constellation Cassiopeia, the big “W” in sky! Perseus is just below Cassiopeia.
Credit: Stardate/McDonald Observatory
You can draw, take pictures and even video the Perseids, but the simplest and most enjoyable thing is to lay back, relax and be patient and you will be rewarded with a great a view.
The best times to look will be in the dark pre-dawn sky on August 11, 12 and 13, 2011.
You can also follow along with Universe Today and Meteorwatch.org with #meteorwatch on twitter. Ask questions, see what others are seeing, share your experiences and images using the hashtag #meteorwatch
Most of all, enjoy your Perseid experience and have fun!
Every year from late July to mid-August, the Earth encounters a trail of debris left behind from the tail of a comet named Swift-Tuttle. This isn’t the only trail of debris the Earth encounters throughout the year, but it might be one of the most notorious as it is responsible for the annual Perseid meteor shower, one of the best and well-known yearly meteor showers.
Comet Swift-Tuttle is a very long way away from us right now, but when it last visited this part of the Solar system, it left behind a stream of debris made up of particles of dust and rock from the comet’s tail.
Earth encounters this debris field for a few weeks, reaching the densest part on the 11th to 13th August.
The tiny specs of dust and rock collide with the Earth’s atmosphere, entering at speeds ranging from 11 km/sec (25,000 mph), to 72 km/sec (160,000 mph). They are instantly vaporised, emitting bright streaks of light. These tiny particles are referred to as meteors or for the more romantic, shooting stars.
Perseid meteor shower
The reason the meteor shower is called the Perseid, is because the point of the sky or radiant where the meteors appear to originate from is in the constellation of Perseus, hence Perseid.
When the Perseid meteor shower reaches its peak, up to 100 meteors an hour can be seen under ideal dark sky conditions, but in 2011 this will be greatly reduced due to a full Moon at this time. Many of the fainter meteors (shooting stars) will be lost to the glare of the Moon, but do not despair as some Perseids are bright fireballs made from larger pieces of debris, that can be golf ball size or larger.
These amazingly bright meteors can last for a few seconds and can be the brightest thing in the sky. They are very dramatic and beautiful, and seeing one can be the highlight of your Perseid observing experience.
So while expectations may be low for the Perseids this year, keep an eye out for the bright ones and the fireballs. You will not be disappointed, even if you only see one!
Join in on twitter with a worldwide event with Universe Today and Meteorwatch.org just follow along using the hashtag #meteorwatch ask questions, post images, enjoy and share your Perseid Meteor Shower experience.
April showers? Yes! The 16th to the 26th this month brings us the April Lyrid Meteor Shower, with the peak occurring on April 22nd.
The meteors in this shower tend to be bright and leave persistent trains as they enter the Earth’s atmosphere. In recent years the shower has averaged 10 to 20 meteors per hour.
You may think that this sounds like a fairly mediocre shower and not worth bothering with, but it has been known for the Lyrids to surge and rates rise rapidly to over 100 per hour! This is what makes this shower so interesting and difficult to predict. Will it be a biggy this year or not?
Lyrid meteors radiate from a point (radiant) in the constellation of Lyra and this is where this shower gets its name. The best time to look for Lyrid meteors will late in the evening on April 22nd after 10 pm as the constellation of Lyra rises up from the northeast horizon.
This will give you 2 or 3 hours of meteor watching before the waning gibbous moon rises and starts to wash out the sky. But still, it’s well worth staying up to see as many bright meteors as possible.
One of the best night sky events of the year is on tap: The Geminid Meteor shower. According to the Royal Astronomical Society, the evening of December 13 and the morning of December 14, skywatchers across the northern hemisphere could see up to 100 “shooting stars” or meteors each hour. This number is what will be seen at the peak of activity, but if conditions are clear you can definitely take the time to observe any time between Sunday night, Dec. 12 to Wednesday morning, Dec. 15.
You can also participate and share in the event on Twitter, with the #Meteorwatch crew.
Of course, meteors are the result of small particles entering the Earth’s atmosphere at high speed, burning up and super-heating the air around them, which shines as a characteristic short-lived streak of light. In this case the debris is associated with the asteroidal object 3200 Phaethon, which many astronomers believe to be an extinct comet.
The meteors appear to originate from a ‘radiant’ in the constellation of Gemini, and so the name Geminid.
For US skywatchers, Sky & Telescope predicts that under a clear, dark sky, one or two shooting stars per
minute will likely be seen from about 11 p.m. local time Monday until dawn Tuesday morning. If you live under the artificial skyglow of light pollution the numbers will be less, but the brightest meteors will still shine through.
For European, and particularly British observers, the RAS says by 0200 GMT on December 14, the radiant will be almost overhead in the UK, making it the best time to see the Geminids. By that time the first quarter Moon will have set so the prospects for a good view of the shower are excellent.
Meteors in the Geminid shower are less well known, probably because the weather in December is less reliable. But those who brave the cold can be rewarded with a fine view. In comparison with other showers, Geminid meteors travel fairly slowly, at around 35 km (22 miles) per second, are bright and have a yellowish hue, making them distinct and easy to spot.
To watch for meteors, all you need are your eyes. Find a dark spot with an open view of the sky and no glary lights nearby. Bundle up as warmly. “Go out late in the evening, lie back, and gaze up into the stars,” says Sky & Telescope senior editor Alan MacRobert. “Relax, be patient, and let your eyes
adapt to the dark. The best direction to watch is wherever your sky is darkest, probably straight up.”
As with most astronomical events, the best place to see meteors is at dark sites away from the light pollution of towns and cities. You can also check with astronomy clubs or science museums if they are hosting any viewing events.
The Geminids will also feature in a Twitter event, called Meteorwatch, where observers can post their text, images and videos to share them with other observers (and also for those having less favorable locations. Anyone with Internet access can join in by following @virtualastro and the #meteorwatch hashtag on Twitter.
The comet of the year for 2010 seems to be Hartley 2. Although this comet is receding from Earth now (its closest approach was in the latter half of October) and growing fainter, it seems to have left us with one last hurrah: The spawning a brief meteor shower.
Although other comets, such as 2009 R1 (McNaught) and 2P/Encke have passed earlier this year, none has presented an especially tempting target for amateur astronomers (both McNaught and Encke were too close to the Sun during perihelion to be easily observed). Additionally, Hartley is the target of a flyby of the Deep Impact probe bringing it further attention.
Meanwhile, observationally, the comet has been somewhat difficult to observe. I went out on October 17th to hunt for it with a 4″ telescope, but despite my best efforts, couldn’t find it. Although the comet was predicted to reach 5th magnitude, the growing nucleus has apparently become so diffuse, reaching over 1° in the sky, that it’s hard to spot. Undeterred, I attempted again this past weekend with my 8″ SCT. Again, my attempts were frustrated. Even a 15 second exposure with my camera barely brought out more than a smudge.
Yet that night we observed several bright meteors radiating from near Cassiopeia which is where Hartley had been a few weeks prior. We checked to ensure there weren’t any other annual meteor showers from that region. Sure enough, there weren’t, and we wondered if there might be a connection between Hartley’s passing and the meteors we witnessed.
Sure enough, just such a shower was a predicted possibility. Whether or not the shower would occur would depend on just how much dust Hartley had given off in the past and how diffuse the cloud had grown (on this pass and others) since its closest approach to Earth was still 12 million km. Although the meteors my friends and I witnessed were notable (around 2nd to 3rd magnitude) they came from the wrong direction. Meteors spawning from Hartley should have a radiant in Cygnus, the swan. But while ours may not have caught these “Hartley-ids”, others have been witnessing a far grander show in the past few nights that seem to come from the right direction.
In Seascape California, Helga Cabral caught a bright fireball. “I saw a bright white ball and tail, arcing towards the ocean. It was quite beautiful and it looked like it was headed out to sea and so picture perfect it could have been a movie!” A similar fireball was reported the same night near Boston, Massachusetts by Teresa Witham. The predicted peak of this shower occurs tonight so if you have a chance and clear skies, go out and look. As with most showers, there may be some stragglers just before and after so you may be able to catch some for the next few nights if conditions tonight aren’t favorable.
Meteors from Hartley 2 will have a relatively low velocity upon entering our atmosphere since the comet is traveling roughly in the same direction. As such, the expected velocity as it hits our planet is a mere 7 miles a second. The result of this is that they will likely travel slowly across the sky, taking perhaps as much as a few seconds. In contrast, the Leonid showers coming later this month have a relative velocity of 45 miles per second, which causes the meteors to streak across the entire sky in less than a second. The lower velocity for the Hartley-ids will also mean they won’t undergo as much frictional heating and will likely glow fainter shades of reds and yellows.
A green and red Orionid meteor striking the sky below Milky Way and to the right of Venus. Zodiacal light is also seen at the image The trail appears slightly curved due to edge distortion in the lens. Taken by Mila Zinkova
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While historically, meteor showers were portents of ill omens, we know today that they are the remnants of ejecta from comets entering our atmosphere. Many showers have had their parent comets identified. But a new study is suggesting that two meteor showers, the December Monocerotids and the November Orionids, may share the same parent.
The possibility of a single comet providing multiple showers isn’t too difficult to imagine. Since comets orbit the Sun in elliptical paths there are two potential points the path can intersect Earth’s orbit: Once on the way in and once on the way out. The trouble is that comets don’t tend to orbit directly in the ecliptic plane (defined by the plane on which the Earth orbits the Sun). Thus, comets only puncture through this plane at points known as “nodes”. As a body passes from the upper half to the lower (where upper and lower are the halves defined by Earth’s north and south poles respectively) this point of intersection of the orbit with the ecliptic plane is known as the descending node. When it heads back up, this is the ascending node. If both nodes happen to lie near enough to Earth’s orbital path, the potential for two meteor showers exists. Another possibility is that orbital evolution cause the nodes to change their position and, over time, crossed Earth’s orbit at two different points.
In principle, identifying a parent comet for two showers is much simpler with the first method. In that instance, the comet still orbits in the same path (or near enough) to be conclusively identified as the progenitor. If such an instance were to arise due to orbital evolution, the case must be much more indirect since interactions with planets, even at fairly large distances, can induce large uncertainties in the orbital history.
The December Monocerotids have been associated with a comet known as C/1917 F1 Mellish. Unfortunately for the researchers, the current orbital characteristics of the comet did not feature nodes in Earth’s orbit and did not match the November Orionids. Thus, to establish a connection between the two meteor streams, the team of astronomers from Comenius University in Slovakia, looked at the characteristics of the showers. In order to track these characteristics, the team utilized a publicly available database of meteor recordings from SonotaCo which uses webcams to capture video of meteors and then compute the orbital characteristics of the debris. However, the two showers did share suspiciously similar distributions of sizes (and thus brightnesses) of meteors as well as the velocity and less so, but still notable, the eccentricity.
This led the team to suspect that the node had evolved across Earth’s orbit sweeping by once in the past to create the stream of debris that forms the November shower, and more recently, crossed our orbit to create the December shower. If this hypothesis were correct, the team expected to also find subtle differences hinting that the November shower was older. Sure enough, the November Orionids show a larger dispersion of velocities than that of the December shower.
In the future, the team plans to revise the orbital characteristics of the parent comet. While they were able to show that the precession of the orbit would allow for the situation described, it was only one of a number of possible solutions. Thus, refining the knowledge of the orbit, perhaps from archival photographic plates, would allow the team to better constrain the path and determine the orbital history sufficiently to reinforce or refute their scenario.
Looking northeast around midnight on August 12th-13th. The red dot is the Perseid radiant. Although Perseid meteors can appear in any part of the sky, all of their tails will point back to the radiant. Credit: NASA
Just a reminder: It’s time to head up on the roof, to the backyard, the pasture, the mountaintop — wherever you have to go to get away from city lights and watch the Perseid meteor shower. But this year, there’s the added show of a planetary conjuction right at sunset. Venus, Saturn, Mars, tiny Mercury and the crescent Moon pop out of the western twilight in tight conjunction. But then stay tuned to the sky for the Perseids. If you haven’t been out to see them yet, Thursday, August 12 and Friday August 13 should be the peak, and already some locations have been reporting 70-80 meteors an hour. No telescope is required to enjoy these two naked-eye events. See below for a sky map and tips on how to share your experience.
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Want to share the event via Twitter? Follow the hashtag #Meteorwatch and see the Meteorwatch website for all you need to know about watching the Perseids.
On Thursday, Aug. 12, from 3-4 p.m. EDT, astronomer Bill Cooke from NASA’s Marshall Space Flight Center will answer questions in a live chat about the Perseids and the best ways to view it. To view and join the chat, go to this link on Aug. 12 a few minutes before 3 p.m. EDT. A chat window will be active at the bottom of the page. Log in, then Bill will start answering your questions at 3:00 EDT. And then…stay up all night with NASA! Later that night — Aug. 12 — from 11:00 p.m. to 5 a.m. EDT, Bill will take your questions via Web chat. You can also “listen” to the Perseids on that page.
