Tag Archives: fireball

Listen to the Chelyabinsk fireball’s infrasound tsunami

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Click image to see and hear multiple explosions of the fireball when it broke apart 12-15 miles high over Chelyabinsk, Russia on Feb. 15, 2013. This video scares me every time I see it.

You’ve probably seen and heard at least one video of February’s fireball exploding over Cheylabinsk, Russia. The shock wave from entry and subsequent break up of the meteoroid blew out thousands of windows, caused part of a building to collapse and set off countless car alarms.

A tiny sampling of the thousands of pea-sized meteorites recovered from the Chelyabinsk region after the fireball. Credit: Mike Farmer

Scientists estimate the incoming object measured about 55 feet (17m) across – as big as a 5-story building – weighed 7,000 tons and blazed across the sky at over 40,000 mph (64,000 kph). The shock pressure and heat upon entry converted much of the mass into dust, seen as a smoky “contrail”, and the rest into thousands of small meteorites that pocked snow drifts in the surrounding countryside.

Click image to listen to the atmospheric “tsunami” that sent waves of infrasound around the globe.

While the Chelyabinsk event was the most impressive witnessed meteor in more than 100 years, its effects were even more far-reaching. Almost 6,000 miles (9,600 km) away in Lilburn, Georgia a full 10 hours after the explosion, infrasound sensors recorded multiple rumbles from the object’s impact with the air.

Infrasound, a very low frequency sound wave that can travel long distances, can’t be heard by human ears but can be detected with sensors. When a large meteor enters the atmosphere it sends ripples of infrasound through the atmosphere and around the planet revealing information about its speed, direction of travel and how much energy it contains.

Locations of the Earthscope’s seismic sensors across the U.S. and into Canada. Click map and see if one is near you. Credit: National Science Foundation / Earthscope

Lilburn is home to one of nearly 400 seismic/infrasound stations in use in the eastern United States. They are part of a large-scale project named Earthscope, an initiative funded by the National Science Foundation that studies the Earth’s interior beneath North America. Although the stations mostly record seismic waves from earthquakes, they also are sensitive to long-period waves of infrasound.

Georgia Tech faculty member Zhigang Peng took the Lilburn infrasound data, sped it up and amplified it so we can heard the reverberations created by the falling meteoroid as it plowed through the atmosphere.

Click image to hear infrasound recording of a North Korean nuclear test and a magnitude 5.1 Nevada earthquake by Peng

“The sound started at about 10 hours after the explosion and lasted for another 10 hours in Georgia,” said Peng. Like a tsunami set in motion by an earthquake, the Chelyabinsk meteoroid created a series of tsunami-like waves in the atmosphere itself. Both travel at nearly the same speed.

Peng has used the same process to convert seismic waves and underground nuclear explosions into audible sound. Click above for a listen. Check out this site for more exploding Chelyabinsk videos.

Update on the fireball that exploded over Russia

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The largest ~ 1 kilogram (2.2 lbs) Chelyabinsk / Chebarkul meteorite found to date alongside many smaller fragments. Credit: Screenshot from video, courtesy press-service Ural Federal University

The sun rose twice over the Ural Mountains in Russia Friday February 15. No one expected the second sun, a meteoroid that slammed into the atmosphere so fast it set the air aglow with a fire even brighter than the real sun. It lasted more than 30 seconds before exploding and sending a shock wave rippling across the city of Chelyabinsk and surrounding countryside.

Thousands of residents of small towns in the area of the fall at and around Lake Chebarkul have been busy hunting for meteorite fragments by looking for holes in the snow cover and then carefully clearing away the white stuff until a little black rock remains. It must sound and look like an Easter egg hunt out there. Some of the locals are cashing in on meteorite fever by offering rides to the big hole in the ice on Chebarkul Lake thought to have been punctured by a meteorite fragment.

Another view of the biggest meteorite fragment. It’s shows regmaglypts or dimples created when high temperatures during entry heat and melt away minerals on the surface. Click to see more images of  meteorites found from the fall. Credit: Screenshot from video, courtesy press-service Ural Federal University

Many of the stones – some real, some obviously fake – are popping up on various auction sites in Russia and elsewhere. A quick check on eBay under “Chelyabinsk meteorite” turned up 29 listings today. How many of those are real? Hard to say.

One meteorite hunter interviewed by a BBC team put it this way: “It’s like hunting or fishing. When you see an animal, your heart starts to beat fast, and when you’re fishing – it’s like pulling the fishing rod and thinking there’s something extraordinary. This is the same – you see a tiny hole, try it, and here it is.”

After more than a week of study, we know a little more about the asteroid that created this shower of stones in large part from information recorded by a network of infrasound sensors operated by the Comprehensive Test Ban Treaty Organization (CTBTO). Their purpose is to monitor nuclear explosions.

https://www.youtube.com/watch?v=H-8ij80vs1E
Recording of infrasound from the Russian fireball that’s been sped up 135 times so we can hear it. The original file was 25 minutes long!

Infrasound, a very low frequency sound wave that can travel long distances, can only be heard by a few animals including elephants. When a large meteor enters the atmosphere it sends ripples of infrasound across the atmosphere around the planet revealing information about its speed, direction of travel and how much energy it contains.

“The Russian meteor’s infrasound signal was was the strongest ever detected by the CTBTO network. The furthest station to record the sub-audible sound was 9,300 miles away in Antarctica,” according to a NASA press release.

Russian fireball on Feb. 15, 2013 recorded by a dashcam

Here’s what we know based on an analysis by Western Ontario Professor of Physics Peter Brown:

* Size: 56 feet (17 meters) in diameter
* Weight: 11,000 tons (10,000 metric tons)
* Speed: 40,000 mph (64,000 km/hour) and broke apart 12-15 miles above Earth’s surface
* Exploded with the power of 470 kilotons of TNT which is equal to more than 23 1940s-era atomic bombs

We looked at the asteroid’s orbit the other day and discovered it belonged to the Apollo family of Earth-crossing asteroids. When farthest from Earth it used to mingle with its many friends in the asteroid belt. Like the majority of asteroids between Mars and Jupiter it has a rocky composition.

Scientists study 53 tiny meteorites from Russian fireball

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Pieces of the Russian meteorite fall are seen in a laboratory in Yekaterinburg on Monday, Feb.18, 2013. Black shock veins are visible in the broken specimen in the background if you look closely. Credit: AP Photo/ The Urals Federal University Press Service, Alexander Khlopotov

Scientists at Urals Federal University in Yekaterinburg have examined 53 meteorite fragments taken from the perimeter of the hole in frozen Chebarkul Lake. The largest is only 7 mm (about a quarter-inch) across; the smallest about one millimeter. Many are covered with dark fusion crust, a layer of melted and blackened rock from atmospheric heating.

The majority of the 53 pieces of the meteorite picked up around the hole at Chebarkul Lake displayed in the lab at the university in Yekaterinburg. The insides of the stones shows the typical pale gray, concrete-like texture of certain common chondrites. Credit: AP / The Urals Federal University Press Service, Alexander Khlopotov

The little stones are a common type of meteorite called a chondrite (KON-drite) that originated in the crust of an asteroid. A long-ago impact sent a fragment of the asteroid flying toward the inner solar system where it ultimately encountered Earth last Friday.

The Russian meteorite, which may receive the name Chebarkul, after the lake and town where it was found, contains about 10% iron-nickel, magnesium-rich chrysolite and sulfite, all common materials found in stony meteorites.

 

Look at how small the pieces are. I have to believe there are many more to be found from the powerful fireball. The sign reads: Meteorite Chebarkul. Credit: AP Photo / The Urals Federal University Press Service, Alexander Khlopotov

Chondrites are classified according to their iron content. Those with 15-20% nickel-iron metal are iron-rich and named “H” chondrites. Meteorites with a 7-11% nickel-iron content are classified as “L” chondrites, and those with the lowest amount of iron are the “LL” variety. Based on the lab’s description, it would appear that the fireball left a trail of L-chondrite crumbs. Let’s hope the hunters and scientists can follow the trail to the bigger ones.

** Update: I’ve recently learned via Russia TV and the New York Times this morning (Feb. 19) that local people are finding hundreds of small fragments buried in the snow. Read the full New York Times article and see more photos HERE.

Must-see videos of spectacular Friday fireball over Russia

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Video of a brilliant fireball over Russia on Feb. 15, 2013 local time

A spectacular fireball exploded over the Russian city of Chelyabinsk more than 900 miles east of Moscow around 9:26 p.m. (CST) Feb. 14 or 9:26 a.m. Feb. 15 local time in Russia this morning.

Frame grab from the video during the early phase as the fireball rapidly brightened

Frame from a few seconds later as the meteor heads toward the horizon

The dashcam videos record one of the most brilliant and amazing fireballs I’ve ever seen. Watch as it becomes nearly as bright as the sun with a strong reflection off the roadway. Loud booms accompanied the spectacle and glass windows were shattered. There are reports of downed power lines and interrupted cell phone service. Some 500 people were treated for injuries, mostly from broken glass sent flying from the shock wave and sonic boom. The roof at a zinc factory in Chelyabinsk may have collapsed from the same.


Video from a different dashcam taken from a different location where the fireball is higher in the sky and approaching at a different angle with an insanely spectacular trail. Click to view.

In the second video, notice how long the smoke trail lasts as the car speeds along in a big hurry to get somewhere. In case you’re wondering, this is not related to the flyby of asteroid 2012 DA14 expected around 1:24 p.m. CST today. One clue is the direction of travel. Had it been “leading” today’s asteroid, the fireball’s path would have been almost directly south to north. Instead it traveled from northeast to southwest.

But they do have one thing in common. Even though one will miss Earth and the other’s trajectory took it straight into our atmosphere, both are small asteroids almost certainly originating from the asteroid belt between Mars and Jupiter.

A hole in Chebarkul Lake, west of Chelybinsk, made by meteorite debris. Small fragments of black rocks were found around the crater. Two other impact sites are reported. Click for more photos and further story. Photo by Chebarkul town head Andrey Orlov.


Great video of the smoke trail also called a meteor train 

In this photo provided by Chelyabinsk.ru, a meteorite contrail is seen over Chelyabinsk on Friday, Feb. 15, 2013. The meteor, which streaked across Russia’s Ural Mts. Friday morning, was the largest reported fireball since the 1908 Tunguska explosion. Credit: AP Photo/Chelyabinsk.ru

The latest estimate of size for the original meteoroid – the name given to the object while still in space before entry into Earth’s atmosphere – is about 50 feet across with an approximate weight of 7,000 tones. The Russian Academy of Sciences released a statement saying the meteor traveled at 33,000 mph and shattered about 18-32 miles above the  ground. Three impact sites are now reported including one that fell through the ice in Chebarkul Lake. Dark, rocky meteorites have also been found.


Short video showing dramatic effect of the shockwave

I’ll be updating this blog with more information and photos throughout the day.

More videos HERE.

NASA video of California fireball helps narrow fall zone

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San Mateo College student Paola-Castilla photographed the fireball on a cell phone while stuck in traffic. Credit: Paola-Castillo

Either meteorites haven’t been found yet or nobody’s talkin’. But videos and eyewitness reports have allowed Peter Jenniskens, principal investigator at SETI Institute, to paint a more detailed picture of the fireball that blazed over the San Francisco Bay area Wednesday evening.

Jenniskens examined the images recorded by two CAMS (Cameras for AllSky Meteor Surveillance) cameras, one near Sunnyvale and another at San Mateo College. Data from two widely-spaced places gives researchers the ability to triangulate distances and altitudes of a meteor’s flight.


The fireball was so bright in NASA’s sensitive camera, it blew out the image, creating some trippy effects.

The cameras tracked the car-sized space boulder from when it started to glow at 53 miles overhead down to 24 miles, when it exploded to pieces. Top speed was 31,300 mph. Jenniskens believes there’s a “good chance a relatively large fraction of this rock survived.”

Peter Jenniskens

Before meeting its earthly fate, the meteoroid circled the sun with a perihelion (closest point to the sun) of 91.8 million miles in nearly the same plane as Earth’s orbit. Practically a next door neighbor. Jenniskens began his search the hills north of the Bay area Friday for meteorite fragments. Let’s hope he finds a few!

If you were (are) in the area and wish to share videos and photographs and report possible meteorite finds, please email: Petrus.M.Jenniskens@nasa.gov

Oct. 17 California fireball may have dropped meteorites

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Last night’s fireball over Belmont, California. The meteor first appears in the constellation Sagittarius and flamed across Ophiuchus and Hercules. The Summer Triangle of Vega, Deneb and Altair is at center and tipped sideways with north to the right. Credit: Wes Jones

Although the Orionid meteor shower’s up at bat this weekend, meteors fall anytime. Those that drop from a random spot in the sky and aren’t connected to a specific comet, as the Orionids are with Halley’s Comet, are called sporadic meteors. On any given night you might see 5-10 sporadic meteors per hour.

Yesterday evening October 17 at 7:42 p.m. local time, a brilliant sporadic meteor created a sensation over the San Francisco Bay-San Jose region where it briefly lit up the night sky like a thousand sparklers. The fireball broke into pieces as it fell, rumbled like thunder and left a glowing train (luminous trail) in its wake. To hear some of the comments posted on the American Meteor Society’s Fireball Report website makes you wish you were there:

“Awesome wild glowing train that turned to smoke.” – Karen

“It must have been really big and/or really bright because it created shadows on the street and the delay between the first shadows appearing and the delayed boom was maybe more than a minute. It was so bright it created shadows on the road from the overhead powerlines.” – Alicia

“The sound was stretched out and there were several pulses, like distant thunder, but louder. After it passed overhead it broke into a number of pieces which continued in the same direction at first and then some diverged near end.” – Frank

“The fireball was clearly breaking up as it flew across the sky. it made the tail appear like a firework sparkler with blue and red and yellow sparks flying off.” – Amanda Titterington


Security cameras at California’s Lick Observatory recorded the fireball. The round, silhouetted structure at left is the telescope dome and the lights in the background are from San Jose.

While some news articles are connecting the fireball to the Orionid meteor shower, it’s completely unrelated. How do we know? The photo above clearly shows it originating in the Sagittarius area located in the opposite part of the sky from Orion. Orionids fly out of Orion which at the time had yet to rise. Because of the meteor’s slow speed, its breakup into fragments and reports of thundery booms that shook residents’ homes after it disappeared from view, there’s a fair chance it may have dropped meteorites. Meteors rumble, thunder and boom when they enter the lower atmosphere traveling faster than the speed of sound.

Meteorite hunters will be checking Doppler weather radar recordings made in the fall zone to see if they can pinpoint a possible search location. Jonathan Braidman of Oakland’s Chabot Space and Science Center, believes that fireball fragments may have fallen in hilly terrain north of Martinez, Cal. For the latest news and reports, please click over to Dirk Ross’s excellent Latest Worldwide Meteorite / Meteorite News site.

Unique UK meteor proves what goes around comes around

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Video of the September 21, 2012 UK fireball. At closest, the meteor was only 33 miles above the Earth’s surface.
On the evening of September 21 a spectacular fireball as bright as the full moon blazed over the British Isles fracturing into dozens of fragments. Traveling at 8 miles per second – barely enough to escape Earth’s gravity – the meteor took an estimated 3 minutes to cross the sky as it sizzled westward over the Atlantic. Because it lingered so long, some observers thought it might be the breakup of a satellite, but the great majority of satellites travel the opposite direction – from west to east – making a chunk of slow-moving space debris the better possibility. Most meteors strike the atmosphere between 11 and 72 miles per second.

A similar Earth-grazing meteoroid / fireball streaked over Wyoming on August 10, 1972 that came as close as 35 miles before skipping back into space. See video below. Credit and copyright: Antarctic Search for Meteorites program, Case Western Reserve University, James M. Baker

155 minutes later another fireball tore across eastern U.S. and Canadian skies before incinerating itself. Were these two sightings connected? Esko Lyytinen, mathematician and member of the Finnish Fireball Working Group of the Ursa Astronomical Association, modeled the meteor’s flight and determined that its slow speed may have allowed it to be captured by Earth’s gravity.

After its British debut, the object orbited once around the Earth and flared to life again over Canada before finally breaking to bits. It’s unknown if pieces survived to land as meteorites. The original meteoroid, the name given a space rock before it enters our atmosphere, is estimated to have weighed from several to tens of tons. Most of it would have burned up miles high, turned to dust and vapor by the heat and stress of entry.


Footage of the Great Daylight Fireball of 1972
While pieces of the meteor did burn up over the North Atlantic, Lyytinen believes a surviving fragment skipped back into space to become a temporary satellite of Earth. Slowed to 5.7 miles per second by its atmospheric encounter, the meteoroid’s fate was sealed – it wasn’t going anywhere but down. After one orbit, it flared a final farewell in a fiery trail over Canada.

Frame grab of the Sept. 21 UK fireball. Click to see video. Credit: CCTV / Youtube

Lyttinen cautions that more study needs to be done to confirm his hypothesis. If proven true, this would be the first time a meteoroid has been observed to graze in and out of Earth’s atmosphere, becoming a temporary natural satellite in the process. For a brief few hours our planet had not one but two moons!

I wish to thank Dirk Ross and his excellent Latest Worldwide Meteor / Meteorite News website for background on the fall. Check out his site as well as science writer Kelly Beatty’s .informative article. Stay tuned for an update.

California fireball drops rare meteorites

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Robert Ward holds a piece of the meteorite from the fireball that streaked across central California and Nevada Sunday morning. Thanks and credit to Dave Gheesling

The first fragments of the California-Nevada daylight fireball were recovered Tuesday by Robert Ward, one of the most prolific meteorite hunters in the world. Ward lives in Arizona and has been fascinated by meteorites since witnessing a fireball as a boy in 1986. In the late 1980s he found his first meteorite and today his collection of personal finds includes space rocks from almost 500 localities. You can read more about Ward in this story by fellow meteorite hunter David Gheesling.

Ward and other meteorite hunters would be looking for black stones that stand out from the native rocks. Freshly-fallen meteorites are coated in a thin layer of black, melted rock called fusion crust from heat generated  by friction and pressure with the air as they fall to Earth. He may also be using a metal detector as many meteorites contain specks of iron-nickel metal.

After a preliminary assessment, it appears that the California fall is a particularly rare type of meteorite called a CM carbonaceous chondrite. I know that’s a mouthful so bear with me. CMs are rich in carbon and contain water and complex organic compounds including amino acids. Here on Earth, amino acids are used by our cells to build the proteins that make and power our bodies.

A fragment of the Murchison meteorite that fell in Australia in 1969. The vial contains microscopic diamonds also found within the rock.

One of the most famous CM chondrites (KON-drites) fell on September 28, 1969 near the town of Murchison, Australia. Some 254 lbs. or 100 kg of specimens were recovered from the Murchison fall.

Local people who picked up the pieces right after the fall said the meteorite smelled like methanol (a form of alcohol), a sure sign that it contained organic compounds.

Closeup of the first meteorites found by Robert Ward from the California fall. Notice the bumpy fusion crust on the piece at right. Credit: Dave Gheesling

Bill Cooke of the Meteoroid Environments Office at NASA’s Marshall Space Flight Center in Huntsville, Ala., estimates that the meteoroid was about the size of a minivan and weighed in at around 154,300 pounds before it struck the atmosphere.  At the time of disintegration it released energy equivalent to a 5-kiloton explosion.

While most meteorites trace their origins to asteroids, CM chondrites like the California fall might be fragments of a comet, which are rich in water and have similar compositions.

Comet Hale-Bopp from April 1997. It was one of the brightest, easiest to see comets in decades. Credit: E. Kolmhofer, H. Raab; Johannes-Kepler-Observatory, Linz, Austria

At the center of all comets is a several-mile-diameter, irregularly shaped “nucleus” made of ice and dust. And it’s as black as a charcoal briquette. Everything we associate with a comet – the glowing head and bright tail – are created when heat and light from the sun boil off and illuminate ice, dust and other rocky materials from the nucleus.

Comets are fragile and known to regularly break into pieces under the stress of solar heat and gravity. CM chondrites like the California fall are also nearly black inside and out. Perhaps, just perhaps, they’re pieces from a long ago shattered comet.

They sure look like chunks of asphalt, but no, these are two additional meteorites from the California fall. The white, circular flecks are chondrules, some of the earliest solid matter to form in the solar system. Credit: Dave Gheesling

There’s been some talk that the meteor – especially given its possible connection to a comet – may be related to the Lyrid meteor shower that peaked this weekend. It’s not. The fireball came from the east in roughly the direction of the sun; the Lyrid radiant was high in the western sky at the time of the fall.

The daylight fireball that streaked over California and Nevada around 8 a.m. this past Sunday. It broke up as it traveled, dropping meteorites onto the foothills of the Sierra Nevada Mountains near the small town of Coloma. Credit and copyright: Lisa Warren

The meteor's flight path recorded by Doppler weather radar. Ground track is shown below it.

Keep your eyes peeled for auroras tonight April 23-24

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It's here! A huge "tongue" of bright aurora speared by faint rays covered the northeastern sky around 10:30 p.m. Monday night seen from the Lester River in Duluth, Minn. As of midnight Mon-Tues. the aurora was still visible through mostly cloudy skies. Photo: Bob King

The effects of an earlier coronal mass ejection from the sun arrived today, jazzing up Earth’s magnetic field and setting the stage for possible northern lights tonight. The Kp index has been at “5″ since this afternoon meaning it’s time once again to put on your tin hats and head out for a look. Observers in the northern U.S. have the best chance of seeing the aurora’s green glow. Find a place with a clear, dark view of the northern sky for the best view.

A coronal mass ejection from July 2002. Solar flares send billows of solar wind particles into space, some of which arrives at Earth and excites the upper atmosphere to glow with auroras. Credit: NASA

You can keep up on activity by clicking the Kp link above and checking the extent of the aurora at the Ovation Auroral Forecast site. Auroras are typically – but not always – most active around midnight to 1 a.m.  Good luck and let us know if you spot any.

While you’re out, you can also catch the last set of space station passes for the area this week. We’ll soon enter a short hiatus of daylight-only passes before the station returns to the morning sky. The times below are for the Duluth, Minn. region. For times for your town, please log in to Heavens Above or plunk your zip code into Spaceweather’s Satellite Flyby page.

The station first appears in the western sky and travels toward the east. If you see it fade midway through a pass, it’s moving into Earth’s shadow and blocked from sunlight.

Lisa Warren of Reno photographed the daylight fireball Sunday morning (April 22) while she and her husband, Rick, were walking their dogs north of the city. Credit and copyright: Lisa Warren

I also updated today’s earlier blog about the California-Nevada daylight fireball and included a link to a set of spectacular photos taken by Lisa Warren of Reno, one of which is featured above. Here’s the link again. 

Space station passes this week:

* Tonight Monday April 23 starting at 8:57 p.m. and passing almost overhead several minutes later. Very bright!
*  Tuesday April 24 at 9:36 p.m. when it’s very close to the crescent moon in the west. Moves across the southern sky before fading in the southeast.
* Wednesday April 25 at 8:40 p.m. Another brilliant overhead pass
* Thursday April 26 at 9:20 p.m. Cruises across the southwestern sky
* Saturday April 28 at 9:03 p.m. Low pass across the southwest

California fireball excitement plus sweet sights in the western sky

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A Lyrid fireball blazes across the sky over Ozark, Ark. Sunday morning during the shower's peak. Vega and the meteor radiant are at top center. Thanks and credit to Brian Emfinger. Click photo to visit Brian's website for more photos.

I managed one Lyrid this morning at the start of dawn. A white spark shot out of Lyra when I looked up from the scope to take in the Milky Way and Summer Triangle. Twilight and clouds soon took over, but I was happy and surprised to see my solo sparkler. Lyrid activity drops off quickly after maximum.

Others with clear skies during Sunday morning’s peak reported a good shower with counts of 10-20 meteors per hour and a few fireballs to boot. The International Meteor Organization results show a peak as high as 30-45 meteors around 8 p.m. CDT April 21 before settling down to 15-20 per hour on the 22nd before dawn.

Lisa Warren of Reno photographed the daylight fireball Sunday morning (April 22) while she and her husband, Rick, were walking their dogs north of the city. Credit and copyright: Lisa Warren

People in California and Nevada yesterday didn’t have to bother looking to know a meteor crashed through their sky. Yesterday around 8 a.m. a fireball brighter than the full moon shot across the sky at supersonic speeds creating a sonic boom that rattled windows and nerves alike. Check out the complete sequence of incredible photos taken by Lisa Warren over Reno.

Most meteoroids – what meteors are called before they burn up as meteors – are the size of chocolate chips or small pebbles, but the ones the size of baseballs and softballs we call fireballs. You’ll never forget the sight if you’re lucky enough to see one.

Another fireball, this one from an earlier Perseid meteor shower in August 2006. Credit: Pierre Martin of Arnprior, Ontario, Canada / NASA

Eye witnesses described the fireball’s brightness as somewhere between the full moon and sun. You know it had to be bright because the meteor was seen in full daylight around 8 a.m. Many witnesses reported loud booms that shook their homes. Check out the American Meteor Society’s Fireball Reports and you’ll see that more than 40 people hopped online to share their impressions.

Like objects in your side view mirror, most meteors appear closer than they are. That’s all the more true when they’re exceptionally bright. Studies show however that meteors burn up at least 50 miles overhead. If big enough to survive and land on the ground, the pieces go completely dark 5-12 miles high during the “dark flight” phase. Only if you see a fireball directly overhead would it lie within that distance. Most sightings are well off toward one direction or another, so you have to add your horizontal distance to the meteor’s height to get a true distance. While some meteors are bright enough to make us think they landed over the hill, almost all are many miles away.

According to Bill Cooke, head of NASA’s Meteoroid Envronment Office, the source of the blast was a meteoroid about the size of a minivan. Did any fragments survive and land as meteorites? Hard to say just yet. It may have completely disintegrated. I suspect meteorite hunters will now be on the ground talking to eyewitnesses and studying Doppler weather data to determine a trajectory and possible fall site. Fireball sightings aren’t uncommon and many don’t lead to meteorites, but some do. If this is one of those, I’ll be touch with news of the hunt.

As the moon waxes from a thin to a thick crescent over the next few days, it rises up from the west to meet and pass the planet Venus. Created with Stellarium

I’m sure some of you are wondering if the fireball was connected to the Lyrid meteor shower which peaked early Sunday. Most likely it was a coincidence. Meteor shower meteors are generally small bits of grit and dust and don’t produce large fireballs that could reach the ground. Still, the Lyrids are known for there occasional bright meteors, so it remains a possibility.

Last night some of you may have attempted to see the very thin lunar crescent low in the west above the planet Jupiter. Tonight it will be higher up and easier to see as it glides upward to meet Venus on Tuesday.

I drew the map for 45 minutes after sunset to include both planets, but you can go out later if you like when the sky’s darker and Venus still up. The Pleiades or Seven Sisters star cluster will lie to the right of the moon tonight.

During crescent phase only a sliver of the moon is illuminated by sunlight; the rest is “darkly” lit by indirect light. Light is reflected from Earth toward the moon and then reflected from the moon back to us. Called earthshine, think of it as a game of ping pong with light.