Meteor Strike: Investigating a Cosmic Crime Scene

A new video tells the tale of an unlikely bit of astronomical forensics

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A meteorite causes panic as it falls in the Ural Mountains region of Russia, Feb. 2013.

Is there anything sneakier than an asteroid? They run silent, run deep and run very, very fast—hurtling toward Earth from any point in the vast bowl of the sky at speeds that can exceed 40,000 mph (64,000 k/h). They typically whiz right past us or plunge harmlessly and spectacularly into the atmosphere, burning up before they hit the ground—unless, of course, they explode in the sky or collide with the surface, leaving a massive footprint of destruction for miles around.

Asteroids—or, in their atmospheric incarnations, meteors or meteorites—don’t do that kind of damage very often anymore, perhaps once every 70 to 100 years on average. But when they do, they can spell big trouble. You could ask the folks living in the Tunguska region of Russia in 1908, where a 330 ft. (100 m) rock exploded in the sky one morning, flattening trees in an 830 sq. mi. (2,150 sq. km) radius. You could ask the dinosaurs—if they weren’t all dead of course, thanks to a 6 mi. (10 km) rock that struck off the Yucatan 65 million years ago, throwing up a sky darkening debris screen that made the planet too cold for them to survive.

You could also ask the folks of  Chelyabinsk, just to the east of Russia’s Ural mountains, who on Feb. 15 of this year, experienced the damage that a 66 ft. (20 m) meteor can do when it explodes in the sky. The air-burst, which injured 1,491 people and damaged 7,200 buildings, fortunately claimed no lives and the damage it did was  fixable, meaning that in the long history of potshots from space the Earth has endured in its 4.5 billion year life, this was a comparatively small and forgettable one.

(MORE: Space Rock Storm: What’s Going On?)

But nothing’s fully forgettable in the modern, wired era, and in this case, that’s turning out to be a very good thing. Within a day of the strike, the Internet was  inundated with footage of the event taken by security cameras, cellphones and the ubiquitous dashboard videocameras the Russians use  to record accidents or carjacking attempts to be used later as evidence. That made the stuff of great YouTube watching, but as Meteor Strike, a new DVD released by PBS shows, it also made for great science.

Even in the modern era, when observatories around the world comb the skies for near-Earth asteroids and catalogue them in a growing census that allows us to track and anticipate their flight paths, there is plenty of ordnance that slips through by. The Chelyabinsk meteor was one of them, but the massive trove of forensic evidence stored by the eyewitnesses has allowed scientists from around the world to analyze  the meteor  and its path to destruction, providing a better understanding of the mechanics of these events, and in turn help us better prepare to defend ourselves against them.

Before the scientists investigating the meteor incident even began their analysis of the cellphone videos, they turned to a bigger and more institutional monitoring system: a global web of 46 atmospheric sensors used to detect evidence of nuclear test blasts. A nuke test—even one below ground—sets off a great wavefront of what’s known as infrasound, or extremely low frequency sounds inaudible to the human ear. An asteroid bursting in the sky gives off a decidedly audible bang, but there’s an infrasound component too.

(MORE: Meteor Dazzles East Coast Night Skies)

When Peter Brown, an astrophysicist at Western Ontario University, checked the records from the bomb blast sensors on the day of the meteor strike, he found that the infrasound given off not only radiated across Chelyabinsk and much of Russia, but around the world several times. “The Earth was really ringing,” he says.

That gave some sense of the mass of the rock (big) and the force of the blast (bigger), but not much more. The next step required a detailed analysis of those more-serendipitous  videos. The video that showed the asteroid earliest in its plunge actually captured it at the moment it began to glow. That would have been at an altitude of about 43 mi. (70 km), since above that point the air is not thick enough to produce rock-burning friction. The angle of flight was about 20 degrees, and by triangulating from the various perspectives from which the scene was recorded, the scientists could determine that the meteor broke up no higher than 18 mi. (30 km) above ground. It took about 10 seconds from entry to breakup, which crude arithmetic means a speed of 40,000 mph (64,000 k/h). And when you know the physics of speed, angle and atmospheric heating—which the folks who study asteroids do—you can calculate the mass of the meteor. In this case it was about 7,000 metric tons, or 15 million lbs. (7 million kg). That’s the mass equivalent of the Eiffel Tower plunging toward Chelyabinsk.

Those, at least, were the back of the envelope calculations. To refine them further, the investigators had to travel to Chelyabinsk and find the precise spots from which the videos were recorded. That involved a simple but ultimately reliable business of standing in the general vicinity of each recording and comparing the view from different position until the perspectives matched. Other videos taken from known locations—such as fixed security cameras—required a lot less calibration. And one, shot from a traffic camera atop a building, allowed investigators to analyze the high-speed, sun dial-like shifting of shadows from light posts, as the flaring meteor sped by. That added another level of granularity to the data.

(MORE: Meteor Blast ‘Heard’ From Australia to Greenland)

Finally, the meteor hunters turned paleontologist, tromping out into the still snow-covered fields around Chelyabinsk, hunting for bits of the meteor that were scattered across the terrain as it blew up. What they were actually looking for were small, pellet-sized holes in the otherwise pristine snow, telltale  wounds from the shotgun spray the meteor gave off. When they found one, they excavated in a large cone surrounding the  hole, sifting the snow until, on occasion, they hit meteor paydirt. They shipped those samples to a lab in Yekaterinburg, where the makeup of the meteor was analyzed. The findings: it was about 10% metal and 90% rock.

That composition, plus the shallow angle of the approach helped prevent Chelyabinsk’s scary day from being its last day. An iron meteor approaching at a sharper angle would surely have stuck the ground. At the right speed, the blast released would have wiped out the town.

There will, surely, be more meteor hits to come. NASA‘s Near Earth Object Program Office coordinates the world’s detection effort, and is developing ways to deflect or destroy meteors. And an old NASA hand, Apollo 9 astronaut Rusty Schweickart, is similarly leading the private sector’s efforts. Last year, Schweickart and his partners established the Sentinel Foundation, a nonprofit grouping working to build and launch an infrared satellite that would look for asteroids from the high ground of solar orbit.

“Sentinel will discover 50% of the city-buster asteroids,” Schweickart says on the PBS  video, using a simultaneously new and spooky term. That might seem to leave a huge margin for error, but it’s a lot more protection than we’ve got so far. “Right now, we’re driving around the solar system without any insurance,” Schweickart says. He and his fellow skywatchers are working to provide us a little.

(VIDEO: Moon-Toting Asteroid Will Buzz By Earth)

5 comments
solardowork
solardowork

Very soon all will look to the Heavens above.

(C/2012 S1)  will give a show no one will forget.

Every one on Earth can track and see most all NEAR EARTH OBJECTS at

    (neo.jpl.nasa.gov)

What a view the International Space Station will get more then a eye full of C/2012 S1.

Largest ever seen in the last 200 years or more, Moon Impact Explosion March 17, 2013.

More small ones Asteroids to Impact, you do not want to be by tall building
if a big enough one impact the earth most all the tall building if not all will
fall.


Fathers and Mothers take your children to a " STAR PARTY " its a gathering of Astronomers some amateur some new to it and many of us have been looking to the Heavens for many years.  There are many a Star Party all over this planet.

From............ Maui Space Surveillance Site Complex (MSSSC)

Or from any of the hills or beaches in the Hawaii Islands at night if you look long enough you will see one, and some nights many of Shooting Stars. People from all over Earth come to the Islands many of them  Astronomers.

 Astronomers from around the world at Dillingham Air Field in Hawaii All are welcome to Hawaiian Astronomical Society Star Party to Look to the Heavens Above. With Many of us that fly in them.


Father like son both Archimedes and his Father Phidias the Astronomer were
well know to all wise men of their day that studied the Heavens Above. Long ago
Wicked men dried to wipe out Archimedes and his Father Phidias from the History
Books.

More small ones very likely, large ones less likely without notice
with all the eyes looking to the Heavens Above.

The PLANETARY DEFENSE
is not to protect Earth from men from Mars.
Nothing would live long on Mars well more than 100 times a year every year it is impacted from meteors of all sizes.
The PLANETARY DEFENSE
It is for all mankind with most
all Nation in on it to stop if can most all collision with EARTH from a ASTEROID
IMPACT. It is if you will a AVOIDANCE SHIELD. "N.E.O.S. Near Earth Object
Shield".

If only one were to hit or IMPACT EARTH on land get ready for a
winter you will never forget. The winter from 1883 -1884 KRAKATOA you will think
was a little pebble, and now the stone comes. Krakatoa was a great mountain till
it erupted with fire and a blast heard thousands of miles away that cast that
Great Mountain into the sea. The Shock Waves were felt around the Globe. The sea
was full of Bodies from the Tsunamis more than 35,000 of them, the sea stayed
red for weeks. 1884 was a year without a summer as the year 1816 was and many
world wide Froze to Death from the KRAKATOA Event.

A Shock Wave was felt in England from a Event
about 7:15 to 7:20 A.M. Siberia time in the morning in June of the year 1908
high in the sky above the Forest in the remote wilderness of Tunguska Siberia
heard an explosion that laid flat more than 800 square miles of the forest with
all the trees pointing away from the center of the blast with most all the trees
laying on their side. Some trees that were right below the blast were still
there looking like telephone poles with no bark or branches left on them.
This Asteroid did not even hit the Ground and this is known by most as
the TUNGUSKA EVENT. For all that lived there it was
WORMWOOD Rev 8:11 the wood became full of worms and the rivers
water no longer sweet and undrinkable.

If a Meteor Shower is big enough
you might think all the Stars are falling from Heaven.



About one every 100 years makes it into the
Earth’s Atmosphere big enough for all to take note. Some make it
to the surface the signs are all over the Planet and Moon from the ones that
have. Ron Suggs  at NASA  Marshall Space Flight Center watched the largest ever seen in the last 200 years or more Moon impact explosion March 17, 2013.



If you need a visual sign of a collided impact
with a planet look to

"SHOEMAKER - LEVY 9" July 1994.

and it was found only a year before in 1993.

The impacts lasted for hours and some pieces were over a mile in diameter.



You Need More Look up "PROJECT
WORMWOOD" Revelations 8: 10 - 11 based on the "TUNGUSKA EVENT" 1908

MOSCOW Russia is now saying it will use missiles
to intercept Asteroid if need be. 

Better to be safe then sorry.

GET READY

Read the one and only book
that will really matter the Bible
While you still can,
and May our Lord
GOD Bless all that do so.

December 2013 the Heavens above COMET "C/2012
S1", "ISON".

The day will come soon enough when

ALL ON EARTH WILL SEE THIS NO MATTER WHERE YOU
ARE. the night side of earth will become day and  day will be blinding
bright. The Bow Shock from the Photo Electric Effect from the Sun's Solar Wind
will really be something.

The sun will be block out from all the space dust.

Shortly thereafter you will think the stars are
falling from the Heavens,

REV 6:13,

REV 16:21

most will be between 60 to 80 pounds that will make it to the ground
surface. Nonstop 12 to 14 hours at a time for two days.


Help others in are Lord's name
Jesus Christ help bring all to know him while you still can. Three kings that
were wise men once flowed a star with a long tail 2,000 years ago. That lead
them to Jesus Christ wise men still look to and hear are Lord Jesus Christ.

The wicked for thousands of years have tried to
wipe are LORD from the History Books.
 

As it was in Noah's day nobody would listen to him giving the warning.
Many thought it was funny till the rain water from the Comet would not stop for days on end.
Very Sad for many will be sorry.

Pray for your love ones and lead them to our LORD while you can.

Matthew 24:37

The Vaporized tail path after going by the SUN will light up the December skies.

On November 1-2, 2013 (C/2012 S1) will pass very close in front of Earth Orbit. Remember its tail is Millions of miles long.

November 28-29, 2013 it will speed up as it rounds the SUN, goes around it.

November 29-30, 2013 it will be clear of the SUN and glow brighter each day there after.
If it makes it passed the SUN?

December 24-26, 2013 it will light the night sky.

January 1 - 5 ,2014  Planets line up in almost a straight line with Comet ISON and our SUN.

January  12 - 17, 2014 the SUN could be blocked out from the comets long tail of star dust. Even if it does not make it around the SUN.

January 14-16, 2014, Earth will be going right through part of its tail path, that (C/2012 S1) took on the way to the SUN.

Comets have rocks of all sizes, dust, water, ice and gases, most all gets Vaporized to a glowing yellow or white if it passed to close to the SUN. This Glowing mass can be seen for a Billion + miles away.  This absorb energy is carried back with the comet in its orbital path some to deep space. 

The Sun can have a effect on a comet like 1986 Halley's Comet that for years we will be having meteor showers from it ETA  AQUARID and ORIONID METEOR SHOWER. Some Meteor Showers can be for a day to more then a week long.

ANOTHER COMET
( C/2013 A1 )

 Discovered on January 3, 2013, by Robert H. McNaught born 1956
he is more then a Experienced Comet Hunter and well know Astronomer.

  COMET
( C/2013 A1 ) could give ( Planet Mars ) more then just a Little Kiss October 20, 2014.

The Lord's Little Helper
Paul Felix Schott

Akram
Akram

There is something called SPEED, and something called VELOCITY;  Speed is scalier; Velocity is Vector with magnitude and direction -"And when you know the physics of speed, angle and atmospheric heating"???  -  like I said there is something called velocity - so why am I unemployed and you write about the square mileage of the line from the circle's center to its edge known as the RADIUS and declare velocities as speed?

Physics?? F = (M) x (g)

Akram
Akram

What is , "an 830 sq. mi. (2,150 sq. km) radius."???  is this a NEW kind of alien measurement?? and you are the science writer or you're married to the bosses daughter?

DanBruce
DanBruce like.author.displayName 1 Like

What is an "830 sq. mi. (2,150 sq. km) radius"?

Akram
Akram

@DanBruce Bruce I just now started this account, and then after posting, saw you had picked up on this "new calculus" - an area to denote a radius.