Posted on by Jon Voisey

April 9th Fireball

In my time watching the skies, I’ve seen quite a few meteors, fireballs, and bolides. The truly notable ones are few and far between, but last Saturday, I caught one that was among the most interesting I’ve seen. It was a slow moving, bright green one with a nice smoke trail that was easily as bright as Venus from where I saw it in the suburbs of St. Louis. I tweeted about it briefly but didn’t think much more about it until I got a response from another person that saw it along with a link to a collection of observations. As nice as the observation was for me, it was nothing compared to the view some others got.

Heading over to the American Meteor Society page for a meteor around this time, it looks like a meteor matching the one I saw generated a pretty good number of reports from across the country. Several have reactions similar to my initial one: This must be a firework. Many reports confirm the smoke trail and fragmentation as well. But the reports that are really fantastic are the ones from Canada.

At the Lunar Meteorite Hunters blog, several reports have been collected. Several of these reports from various locations in Ontario report the meteor being as bright as a full moon and lighting up the entire sky! One even notes that they could hear a fizzling noise, a rare phenomenon thought to occur when the passage through the atmosphere creates an ionized path that interacts with the Earth’s magnetic field creating radio waves that could induce physical vibrations in the air around the observer. Another comment reports a sonic boom around the same time (although sonic booms would occur well after the meteor was visible due to the sluggish nature of sound waves, much like the delay between lightning and thunder).

It doesn’t look like NASA’s All Sky Fireball Network caught this fireball, but an amateur observatory equipped with an all sky camera for detecting fireballs did catch the event.

The green color for such meteors is uncommon but not unprecedented. The presence of magnesium ions is responsible for this color. Interestingly, another famous meteor, the Peekskill meteor, also had a green color and rivaled the full moon in brightness. This meteor became famous because it was independently captured in at least sixteen videos (here’s one showing the green tint) as well as for surviving intact to the ground and damaging a car.

Meteors of this intensity are quite rare but bright fireballs like this seem to peak around the vernal equinox. In the weeks surrounding that day, the rate of such events increases around 10-30%.

Posted on by Nancy Atkinson

Incoming! New Camera Network Tracks Fireballs

http://science.nasa.gov/science-news/science-at-nasa/2011/01mar_meteornetwork/

How often have you seen a meteor streak across the sky and wondered where it came from and what it was? A new network of smart cameras that NASA is setting up will hopefully help answer those questions for as many fireballs as possible, at least in the US.

“If someone calls me and asks ‘What was that?’ I’ll be able to tell them,” said William Cooke, head of NASA’s Meteoroid Environment Office. With the new camera network, Cooke and his team hope to have a record of every big meteoroid that enters the atmosphere over the certain parts of the U.S. “Nothing will burn up in those skies without me knowing about it!” he added.

And the exciting part is that Cooke is looking to partner with schools, science centers, and planetaria willing to host his cameras.

It is estimated that every day about 100 tons of meteoroids — fragments of dust and gravel and sometimes even big rocks – enter the Earth’s atmosphere. But surprisingly, not much is known about the origin of all this stuff.

Groups of these smart cameras in the new meteor network will be able to automatically triangulate the fireballs’ paths, and special software will be able to compute their orbits.

In other U.S. meteor networks, someone has to manually look at all the cameras’ data and calculate the orbits – a painstaking process.

“With our network, our computers do it for us – and fast,” said Cooke.

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The network’s first three cameras, each about the size of a gumball machine, are already up and running. Cooke’s team will soon have 15 cameras deployed east of the Mississippi River, with plans to expand nationwide.

How can you get involved? Here is the criteria for the locations Cooke is currently looking for:

1. Location east of the Mississippi River
2. Clear horizon (few trees)
3. Few bright lights (none close to camera)
4. Fast internet connection

The smart meteor network uses ASGARD (All Sky and Guided Automatic Realtime Detection) software, developed at the University of Western Ontario, which hosts the Southern Ontario Meteor Network, which took the video at the top of this article. The software processes the visual information and performs the triangulation needed to determine the orbits and origins of the fireballs.

The cameras can also provide information on where any potential meteorites may have landed, which is great for meteorite hunters and scientists. Getting a piece of a space rock is like a free sample return mission.

NASA's Smart Meteor Network is catching more than fireballs. Click on the image to see a movie where a bird stops to rest on one of the cameras in Georgia.

All cameras in the network send their fireball information to Cooke and to a public website. Teachers can contact Cooke at [email protected] to request teacher workshop slides containing suggestions for classroom use of the data. Students can learn to plot fireball orbits and speeds, where the objects hit the ground, how high in the atmosphere the fireballs burn up, etc.

But anyone can try meteor watching on their own, without being part of the network.

“Go out on a clear night, lie flat on your back, and look straight up,” Cooke said. “It will take 30 to 40 minutes for your eyes to become light adapted, so be patient. By looking straight up, you may catch meteor streaks with your peripheral vision too. You don’t need any special equipment — just your eyes.”

Then – if you are lucky to see some bright fireballs — you can check the fireball website to find out more information about what you saw.

Source: Science@NASA

Posted on by Nancy Atkinson

Meteorite Recovered from April 14 Fireball

Christopher and Evan Boudreaux hold the first recovered meteorite from the April 14, 2010 Wisconsin fireball. The first stone was recovered 22 hours after the fall. Credit: Terry Boudreax, shared by Michael Johnson from Rocks From Space

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Via the Astro Bob and Rocks From Space websites comes news that the first meteorite has been recovered from the spectacular fireball that was seen over seven states on April 14, 2010. Brothers Christopher and Evan Boudreaux from southern Wisconsin located a piece of what was likely a meter-wide space rock, according to NASA’ Near Earth Object office. Astro Bob said that pieces of meteorite from Wednesday night’s amazing fireball appear to have fallen over the Livingston, Wisconson area between Platteville and Avoca. If you’re in that area, maybe you’ll have time to do a little meteorite hunting this weekend. But always get permission before going on any private property.

The image above, as well as a close-up of the meteorite, below, are courtesy of Michael Johnson, who hosts the Rocks From Space website Johnson said that according to Mike Farmer, a professional meteorite hunter, the meteorite appears to be an H chondrite.

The first recovered meteorite from the April 14, 2010 fireball. Photo by Terry Boudreaux (c) 2010, via Rocks From Space, used by permission.

Astro Bob indicated there is a meteorite for sale on e-Bay claiming to be from the April 14 fall, but it is not, so beware.

According to NASA’s NEO office, data collected by scientists at NASA’s Marshall’s Space Flight Center in Huntsville, Alabama indicate the parent body of the fireball was not associated with the Gamma Virginids meteor shower, which was taking place at the time the fireball entered the atmosphere. Instead, the small space rock more than likely originated from somewhere in the asteroid belt.

The head of the NEO office, Don Yeomans, said that when the fireball disintegrated high in the atmosphere, it released energy equivalent to the detonation of approximately 20 tons of TNT.

“Knowing the size of this small asteroid helps us determine the frequency of such occurrences,” Yeomans said. “Asteroids this size are expected to enter Earth’s atmosphere about once a month.”

Here’s a mash-up of webcams, dashboard-cams etc. that captured the fireball.

Sources: Astro Bob, Rocks From Space, NASA’s NEO office, JPL

Posted on by Nancy Atkinson

Huge Fireball Seen Over 7 Midwest US States

Lots of buzz this morning about a huge fireball seen late April 14, 2010 over at least seven midwestern US states including Wisconsin, Michigan, Iowa, Minnesota and Illinois (that’s where I am!) The video above was taken from the dashboard camera of a police vehicle in Howard County, Iowa, which is near the Minnesota border. Another video, from the University of Wisconsin-Madison caught the meteor. The flash even showed up on a National Weather Service Doppler radar image from the Quad Cities in Iowa. The image shows the fireball’s smoke trail caught at 24,000 feet (the small squiggle near Grant and Iowa counties.) Several reports (this one too!) of booms, shaking and flashes have been posted online. Did you capture any images or video? First, you might want to contact the International Meteor Organization, a nonprofit that watches over amateur meteor sightings. But we’d like to see them too! Post a link in the comments or send an email to me.

Posted on by Nancy Atkinson

Video, Images of Ireland Fireball?

So far, no images or video have surfaced of the huge fireball that was reported in the skies over Ireland on February 3, 2010. The Daily Mail posted a video, but it appears to be one from a year ago, maybe earlier. They write that meteorite hunters are on the look-out for fallen space rocks in Ireland, and David Moore of Astronomy Ireland is quoted as saying that meteorites likely landed on Irish soil and not at sea, as many witnesses who saw it along the coast said it was traveling inland.

“This is a huge event,” Moore said, “There’s a good chance we may end up finding this one.”
Continue reading “Video, Images of Ireland Fireball?”

Posted on by Nancy Atkinson

Huge Fireball Reported Over Ireland

We’re seeing reports popping up on the internet of a huge fireball spotted over Ireland at around 6pm local time on Feb. 3, 2010. There was a video posted to You Tube which claimed to be footage of the event, but it now seems that was old footage, so we have removed the embedded video. (We’ll post any new verified images or videos when they become available.) Any Irish readers out there see anything? The Irish Times said members of the public throughout the country have been reporting sightings of the fireball. The Times quoted Tommy David Moore from Astronomy Ireland: “A major explosion happened in the sky over Ireland. We think it’s a fireball, that’s a rock from space the earth has slammed into and they burn up as huge shooting stars. This one appears to have lit up the whole country. The phones here in Astronomy Ireland are going crazy.”
Continue reading “Huge Fireball Reported Over Ireland”

Posted on by Nancy Atkinson

Video of Utah Fireball

Early Nov. 18th, eyewitnesses reported an explosion in the atmosphere above Colorado, Utah, Wyoming and Idaho in the western United States. Some said the fireball “turned night into day” and produced shock waves that shook the ground when it exploded just after midnight Mountain Standard Time. Infrasound recordings of the blast suggest a small asteroid hitting Earth’s atmosphere and exploding with an energy of 0.5 to 1 kiloton of TNT. As the sun rose in the morning, remnants of the explosion were visible as noctilucent clouds over the region. The best video of the extremely bright event was just recently released, from the University of Utah’s Eccles Observatory.
Continue reading “Video of Utah Fireball”

Posted on by Nancy Atkinson

Researchers Observe Extra-galactic Meteor

intergalalctic-meteor.thumbnail.jpg

The common belief is that all meteors come from inside our solar system. Most meteors are thought to be pieces of comet dust or fragments of asteroids that enter Earth’s atmosphere and burn up before they hit the ground, leaving a fiery trail we call “shooting stars.” But a recent observation might put a hole in the idea that these space rocks only come from the immediate vicinity of our solar system. A group of astronomers in Russia believe they observed a meteor of extragalactic origin.

On July 28, 2006, Victor Afanasiev from the Russian Academy of Sciences was making observations using a 6 meter telescope equipped with a multi-slit spectrometer. By chance, he observed the spectrum of a faint meteor as it burned up in the Earth’s atmosphere, and in looking at the data, found several anomalies. First was the speed at which the meteor was traveling. This meteor hit the atmosphere at about 300 kilometers per second, which is quite extraordinary. Only about 1% of meteors have velocities above 100 km/sec, and no previous meteor observations have yielded velocities of several hundred km/s. So where did this one come from?

Since the Earth moves around the galactic center at about 220 km/s, Afanasiev says the meteor’s origin cannot easily be explained by reference to the Milky Way. It appears that it came from the direction in which the Earth and the Milky Way is travelling towards the center of our local group of galaxies. “This fact leads us to conclude that we observed an intergalactic particle, which is at rest with respect to the mass centroid of the Local Group and which was ‘hit’ by the Earth,” Afanasiev and his team say in their paper.

Afanasiev also noted that the spectra of this meteor showed it was made of iron, magnesium, oxygen, iodine and nitrogen. These materials, particularly the metals, form inside stars. Additionally, spectral analysis showed features typical from the materials being strongly heated with the temperatures of 15000 – 20000K. Afanasiev says this differs widely from materials of terrestrial-type rocks and is suggestive of extrasolar or presolar materials.

Another difference was the size of the meteor. The researchers calculated that the meteor was several tens of a millimeter in size. This is two orders of magnitude larger than common interstellar dust grains in our galaxy. They estimated its size by integrating the equation of mass loss jointly with the equation of the variation of the density of the atmosphere. The research team noted that their size estimate, which they admit come from “rather coarse assumptions,” agrees with the expected parameters of the speed of interstellar meteors, which could be as high as 500 km/s.

The team subsequently made other observations to see if other meteors could perhaps be from outside our galaxy. In a total observing time of 34.5 hours during Oct-Nov 2006, they observed 246 meteors, 12 of which had velocity and direction to possibly have come from outside our galaxy.

Afanasiev and his team say there are many questions to be answered about their findings. For example, how metal-rich dust particles came to be in the extragalactic space, and why the sizes of extragalactic particles are larger by two orders of magnitude (and their masses greater by six orders of magnitude) than common meteors. Also, if extragalactic dust surrounds galaxies, could this be observed with infrared telescopes like the Spitzer Space Telescope? And is this dust spread out evenly in the universe or could it be found in clumps that might show up in the form of irregularities on the cosmic microwave background, observed by WMAP (Wilkinson Microwave Anisotropy Probe)?

With all our incredible observatories like Hubble, Spitzer, Chandra, etc, we have the opportunity to see outside of our galaxy. But now we have evidence that we actually might be interacting with extragalactic material as well.

Original News Source: Arxiv