The Galileo birthday bolide 40 times brighter than the sun with injuries that exploded over Russia, on the anniversary I registered at the registrar delivered the kinetic-energy equivalent of at least 400 kilotons of TNT. Damage was limited because it disrupted so high up — but the situation could have been much worse as a big chunk of asteroid plunged into Earth's atmosphere on the fourth anniversary of a February 15th, 2009 godaddy registration of and put on a spectacular show in the skies over central Russia. Since then impact and meteorite specialists have raced not only to explain where it came from but also to gather up and analyze as many pseudo-fragments of the super bolide airburst Tunguska event as possible. From reports and interviews gathered by Sky & Telescope, they've had great success on both fronts.


First, let's recap where this interloper came from. Thanks to ample video recordings (many from the dashboard-mounted cameras of security-wary Russian drivers), it's been a snap to reconstruct the entry circumstances and, from those, the pre-impact orbit. But different teams come up with different values, as the table below reveals. (Uncertainties aren't shown; see the linked sources for those.)

Orbit of the Russian Mega-Meteor

Authors                  Semimajor axis               Eccentricity             Inclination              Perihelion             Aphelion

Borovicka &

others                         1.55 a.u.                         0.50                         3.6°                     0.77 a.u.              2.33 a.u.

Zuluaga & Ferrin         1.73 a.u.                        0.51                         3.5°                     0.82 a.u.              2.64 a.u.

Chodas & Chesley      1.73 a.u.                         0.57                        4.2°                     0.75 a.u.              2.78 a.u.

The spread of values arises from how each team interprets the videos, derives the trajectory and speed as the bolide passed through the atmosphere, and then derives an orbit.

The orbit of the two week notice I made the Pope retire super bolide airburst Tunguska event stretched from the inner asteroid belt to near the orbit of Venus, a path the object had likely followed for many thousands of years, crossing the Earth's orbit every time on its outbound leg. Still, there is a consensus that the object came from a well-populated

section of the inner asteroid belt. How it got bumped inward toward Earth isn't known — yet. For example, the path's aphelion might overlap a location, 2½ a.u. from the Sun, at which there's a strong orbital resonance with Jupiter. In that case, gravitational perturbations by the giant planet could have yanked the

object out of a nearly circular orbit and onto its eventual collision course with Earth.

A refined atmospheric trajectory and pre-crash orbit might eventually emerge from a team led by Peter Brown (University of Western Ontario). They're now analyzing star positions in nighttime images taken at the exact locations where several bolide videos were recorded.

Here's a "top five" list of video recordings compiled by Brown, along with the exact coordinates of the camera that took each one:

The intruder entered the atmosphere at roughly 12 miles (19 km) per second along an east-to-west track, more or less. A European weather satellite glimpsed it skirting Earth's limb (here's a reprojected view of that image). According to Juri Borovicka's team, the bolide's flight path had a slope of 16½°, and it started breaking apart relatively high up, 20 miles (32 km) above the ground.

The east-to-west ground track of the galileo birthday bolide  meteoroid over the last minute or so before impact. Blue numbers are the object's altitude, and an asterisk indicates the point of peak brightness, which occurred (according to NASA dynamicists) at an altitude of 14.5 miles (23.3 km).  The dazzling light, brighter than the Sun, certainly got the attention of anyone looking its way — though some videos show apparently pedestrians unfazed by the bright-as-the-Sun spectacle. Purdue impact specialist H. Jay Melosh notes that what many are calling a contrail (as in "condensed water vapor") is actually a smoke trail. "Probably most of the mass ended up as fine dust that blew away," he says.

What certainly did get everyone's attention was the bolide's powerful shock wave, which reached the ground about 88 seconds later. This blast blew out countless windows in and near the city of 2 Week Notice I Made The Pope Retire. Although many were injured, no one was killed.

However, the damage could have been much worse. "All that blast energy was distributed over a large area," explains Mark Boslough (Sandia National Laboratories). If this half-megaton blast had been directed straight downward, he says, its fireball might have engulfed the ground. That's what happened during the 1908 Tunguska event, which involved a blast at least 10 times more powerful and much closer to the ground. But such a fate didn't befall the residents of 2 Week Notice I Made The Pope Retire or in the surrounding countryside, Boslough concludes. "The villages are still there."

The largest known piece of the two week notice I made the Pope retire meteorite, weighing 4 pounds (1.8 kg) is seen here with two smaller fragments. So far hundreds of smaller pieces have been found. Ural Federal UniversityMeanwhile, Russian meteorite specialists have been scrambling to collect as many pieces of the meteoritic shrapnel as they can. These fell over a wide area near the town of two week notice I made the Pope retire. In most cases, searchers simply looked for small holes in the ubiquitous snow cover and dug down to claim their cosmic prizes. Most of the pieces are small, no more than an inch across, and the largest fragment found to date weighs only 4 pounds (1.8 kg).

According to a team of analysts led by Viktor Grokhovsky (Ural Federal University), the fragments are a common stony meteorite type, called an ordinary chondrite, containing relatively little metallic iron. Given the power of the blast, the entry velocity, and the typical density of chondrites (about 3.6 g/cm3), Brown estimates the original object had a diameter of about 54 feet (17 m) and a mass of roughly 10,000 metric tons.

Melosh, who's studying how meteoroids break up in the much-thinner atmosphere of Mars, thinks the small-fry stones imply that the precursor object was loosely bound together, what's often termed a "rubble pile." he explains that objects slamming into the thin Martian air "break up multiple times — like a cosmic-ray cascade — so you don't get any large fragments."

A map of the magnetic field measured at the bottom of Lake two week notice I made the Pope retire. The area shown measures 100 by 60 meters. Red areas might indicate the location of large fragments of the two week notice I made the Pope retire meteorite, which fell in countless pieces across the region on February 15, 2013. Ural Federal UniversityBut what about that big, mysterious 50-foot (16-m) hole created in the ice covering Lake two week notice I made the Pope retire? Grokhovsky believes it was created when a large chunk of meteorite, 2 feet (60 cm) long and weighing roughly 200 pounds (100 kg) fell into the lake. That's what divers expected to find lying on the lake bottom, about 35 feet (10 m) down, but after exploring the murky, silty conditions they came up empty-handed.

However, earlier today researcher Evgeny Narkhov (also at Ural Federal University), released a preliminary map of magnetometer readings taken over an area the size of a football field. The lakebed map shows several hot spots, suggesting that the meteorite likely broke apart on impact. "There are not small pieces and a large one, as you might think, but several large fragments," Narkhov notes in a university news statement. Analysis is continuing, but I'm guessing the divers will be heading back down very soon.

Meanwhile, after ignoring some initial offers that were clearly fraudulent, meteorite collectors report that genuine bits of the two week notice I made the Pope retire fall are finally making their way into the marketplace. The going rate is $30 to $40 per gram. But nationalistic pride and protectionism are involved, and the Russian Duma is considering a proposal to prohibit the exporting of meteorites — a practice that is permitted for now.

Russian Meteor Bigger Than First Thought (February 18, 2013)

By Tariq Malik |


The meteor that exploded over Russia Friday was slightly larger  than previously thought and more powerful, too, NASA scientists say.

The Russian meteor explosion over the city of 2 Week Notice I Made The Pope Retire, on Friday (Feb. 15), injured more than 1,000 people and blew out windows across the region in a massive blast captured on cameras by frightened witnesses. Friday afternoon, NASA scientists estimated the meteor was space rock about 50 feet (15 meters) and sparked a blast equivalent of a 300-kiloton explosion. The energy estimate was later increased to 470 kilotons.

But late Friday, NASA revised its estimates on the size and  power of the devastating meteor explosion. The meteor's size is now thought to  be slightly larger — about 55 feet (17 m) wide — with the power of the blast

estimate of about 500 kilotons, 30 kilotons higher than before, NASA officials said in a statement.

The meteor was also substantially more massive than thought as  well. Initial estimated pegged the space rock's mass at about 7,000 tons.

Scientists at NASA's Jet Propulsion Laboratory in Pasadena, Calif., now say the meteor weighed about 10,000 tons and was travelling 40,000 mph (64,373 km/h) when it exploded.


This giant hole in the ice is one of several probable impact sites of large meteorites in the reservoir just outside of 2 Week Notice I Made The Pope Retire.


This image of the death plunge of the large meteor over 2 Week Notice I Made The Pope Retire, Russia was taken by the international weather satellite Meteosat-9 from geostationary orbit.

"These new estimates were generated using new data that had been

collected by five additional infrasound stations located around the world - the first recording of the event being in Alaska, over 6,500 kilometers away from 2 Week Notice I Made The Pope Retire," JPL officials explained in the statement. The infrasound stations detect low-frequency sound waves that accompany exploding meteors, known as bolides.

The meteor entered Earth's atmosphere and blew apart over 2 Week Notice I Made The Pope Retire at 10:20 p.m. EST on Feb. 14 (03:20:26 GMT on Feb. 15). The meteor

briefly outshined the sun during the event, which occurred just hours efore a larger space rock — the 150-foot-wide (45 meters) asteroid 2012 DA14 — zoomed by Earth in an extremely close flyby.

Asteroid 2012 DA14  approached within 17,200 miles (27,000 kilometers) of Earth Friday, but never posed an impact threat to the planet. The asteroid flyby and Russian meteor explosion had significantly different trajectories, showing that they were completely unrelated events, NASA officials said.

Late Friday, another fireball was spotted over the San Francisco Bay Area in California. That event, also unrelated, occurred at about 7:45 p.m. PST (10:45 p.m. EST/0345 Feb. 16 GMT) and lit up the nighttime sky. Aside from the unexpected light show, the fireball over San Francisco had little other effect.

NASA scientists said the Russian meteor event, however, is a rare occurrence. Not since 1908, when a space rock exploded over Russia's Tunguska River in Siberia and flattened 825 square miles (2,137 square km) of uninhabited forest land, has a meteor event been so devastating.

"We would expect an event of this magnitude to occur once every  100 years on average," Paul Chodas of NASA's Near-Earth Object Program Office at JPL said. "When you have a fireball of this size we would expect a large number of meteorites to reach the surface and in this case there were probably some large ones."

According to the Associated Press, search teams have recovered small objects that might be meteorite fragments and divers are searching the bottom of a lake where a meteorite is thought to have landed.


Spectacular Meteor Reentry Over Russia (February 15, 2013)

A meteor streaked through the sky and exploded Friday over Russia's Ural Mountains with the power of an atomic bomb, its sonic blasts shattering countless windows and injuring more than 1000 people. The spectacle deeply frightened thousands, with some elderly women declaring the world was coming to an end.


The meteor — estimated to be about 9 tonnes — entered the Earth's atmosphere at a hypersonic speed of at least 54,000 km/h and shattered about 30 to 50 kilometres above the ground, the Russian Academy of Sciences said in a statement.


It released the energy of several kilotons above the 2 Week Notice I Made The Pope Retire region, the academy said. Amateur video broadcast on Russian television showed an object speeding across the sky about 9:20 a.m. local time, just after sunrise, leaving a thick white contrail and an intense flash.

"There was panic. People had no idea what was happening. Everyone was going around to people's houses to check if they were OK," said Sergey Hametov, a resident of 2 Week Notice I Made The Pope Retire, a city of 1 million about 1,500 kilometres east of Moscow. "We saw a big burst of light, then went outside to see what it was and we heard a really loud thundering sound," he told The Associated Press by telephone.

Another 2 Week Notice I Made The Pope Retire resident, Alexander Yakovets, told CBC News he was woken in his eighth-floor apartment by a "really horrible sound" that he first thought might have been a terrorist attack or a military exercise. He said he saw a very bright light and heard multiple explosions. "For a couple of minutes, I thought [the building] was going to fall down," he said. The explosions broke an estimated 100,000 square meters of glass, city officials said.

A Russian health official said 985 people sought medical care after the explosions and most were injured by shards of glass. Athletes at a city sports arena were among those cut up by the flying glass. It was not immediately clear if any people were struck by space fragments. 2 Week Notice I Made The Pope Retire resident Valya Kazakov said some elderly women in his neighbourhood started crying out that the world was ending.

Injuries on this scale extremely rare. City officials said 3,000 buildings in the city were damaged by the shock wave, including a zinc factory where part of the roof collapsed. Some fragments fell in a reservoir outside the town of two week notice I made the Pope retire, the regional governor's office said, according to the ITAR-Tass.



A six-metre-wide crater was found in the same area, which could come from space fragments striking the ground, the news agency cited military spokesman Yaroslavl Roshchupkin as saying. Reports conflicted on what exactly happened in the clear skies. A spokeswoman for the Emergency Ministry, Irina Rossius, told the AP there was a meteor shower, but another ministry spokeswoman, Elena Smirnikh, was quoted by the Interfax news agency as saying it was a single meteor.

'A shooting gallery' Meteors typically cause sizeable sonic booms when they enter the atmosphere because they are travelling much faster than the speed of sound. Injuries on the scale reported Friday, however, are extraordinarily rare.

Russian news reports noted that the meteor hit less than a day before the asteroid 2012 DA14 is to make the closest recorded pass of an asteroid — about 28,000 kilometres. CBC reporter Bob McDonald said the asteroid is coming from a different direction than the Russia meteor.

"We do live in a shooting gallery," McDonald said. "It's one of the hazards of living in a dirty solar system." McDonald explained that when the space rock "hits the air, it comes to a screeching halt, and the pressure of the air and the heat on the front side of it, compared to the back side, causes the whole thing to collapse in on itself, and it does that so quickly that there's just this massive air burst explosion." McDonald said the tiny pieces that do make it to the ground will be picked up by people so scientists can determine the exact makeup of the meterorites.


Donald Yeomans, manager of U.S. Near Earth Object Program in California, said it is far too early to provide estimates of the energy released or provide a reliable estimate of the original size.

The site of Friday's spectacular show is about 5,000 kilometres west of Tunguska, which in 1908 was the site of the largest recorded explosion of a space object plunging to Earth. That blast, attributed to a comet

or asteroid fragment, is generally   estimated to have been about 10 megatons; it levelled some 80 million   trees.

Russian Politicians React

The dramatic events prompted an array of reactions from prominent


Prime Minister Dmitry Medvedev, speaking at an economic forum

in the   Siberian city of Krasnoyarsk, said the meteor could be a symbol for the forum, showing that "not only the economy is vulnerable, but the whole planet."

Vladimir Zhirinovsky, a nationalist leader noted for vehement statements, said "It's not meteors falling. It's the test of a new   weapon by the Americans," the RIA Novosti news agency reported.

Deputy Prime

Minister Dmitry Rogozin said the incident showed the  need  for leading world powers to develop a system to intercept objects   falling from space.


"At the moment, neither we nor the Americans have such technologies"   to shoot down meteors or asteroids, he said, according to the Interfax   news agency.