On June 30, 1908, the object, the size of the building, fell from the sky and exploded in the atmosphere over Siberia. The Tunguska event, named after the river, flattened trees for 800 square miles. It took place in one of the least populated places in Asia and no one was killed or wounded. But Tunguska's aviation is the strongest event of strokes in human history and remains mysterious because scientists do not know the source of this object or whether it is an asteroid or a comet.
One hypothesis: It was Beta Taurid.
Taurids are meteor showers, occurring twice a year, at the end of June and at the turn of October or November. June meteors are Beta. They strike the day when the sunlight showers the "falling stars" that are visible during the meteor shower during the year.
The new calculation by Mark Boslough, physicist at Los Alamos National Laboratory, shows that the tree fall pattern in Siberia is compatible with the asteroid coming from the same area in the sky as the Taurid swarms. Boslough and physicist Peter Brown of Western University in London, Ontario, presented this month's presentation at the American Geophysical Union Autumn meeting in Washington, where they called in June a special observation campaign to search for Tunguska classes or larger objects embedded in the Taurids.
Within a few years the Earth passes next to the densest material cluster in the Taurid stream – and 2019 will be like that. Researchers say it presents potentially the richest batch of incoming materials since 1975. When the seismometers left on the moon by Apollo astronauts recorded a stroke in a Taurid swarm.
There are no objects in our catalog that have any significant probability of impact over the next 100 years
"If the Tunguska facility was a member of the Beta Taurid stream … then the last week of June 2019 will be another occasion with a high probability of collision with Tunguska or near mistakes," the AGU told them.
"While we do not anticipate another tunguska, an increased population of small NEOs [near-Earth objects] in Beta Taurida, it would increase the likelihood of another such event on next year's anniversary of Tunguska or near it "- they concluded.
To be clear, no one says that June should be declared National wear of the helmet. Even if there is an "improved" number of Tunguska objects in the Taurid stream, the probability of hitting the Earth remains very low. Space stones rarely reach as close as our moon.
Experts have a simple explanation for this: the space is large. It is much easier to miss the Earth than to hit it. Of course, it can happen, and in 2013, when an object smaller than the Tunguska impactor hit the atmosphere in Russia near the city of Chelyabinsk, creating a fireball and shockwave, which smashed windows and injured more than 1,000 people.
In the entire recorded history of mankind, the number of people killed by asteroid impact is zero.
"This is not something that should keep you at night," Brown said.
Boslough and Brown do not know if there is actually a "reinforced" population of relatively large asteroids lurking in the Beta Taurids. It's a guess.
In the perspective, Boslough presents the threat of an asteroid hitting: "This is one of the unlikely but potentially highly risky risks that are difficult to determine and difficult to discuss. The probability of death for many people after asteroid attack is super, very low, but not zero. "He adds:" There are so many other threats that are more risky. "
Astronomer Amy Mainzer, who hunts for asteroids in NASA's Jet Propulsion Laboratory and is the lead investigator of the Proposed Near-Earth Lens Camera (NEOcam), an infrared space telescope that will study Earth's orbit in search of potentially dangerous asteroids, said scientists have identified over 90 percent of objects large enough to cause a catastrophe on a global scale.
But moving down the size scale, the census is much more spottier. Only about 30 percent of medium-sized objects were found – 140 meters (460 feet) or more. And she said that only about 1 percent of objects were found that have the size of a Tunguska impactor that is about 40 meters (130 feet) in diameter. She said she welcomed the idea of a special effort to find items in the Taurid swarm in June.
One more calming note: the large asteroids identified so far do not pose any significant threat to the Earth, as long as anyone can recognize them.
This is not something that should keep you at night
"There are no objects in our catalog that would have a significant probability of impact in the next 100 years," said Paul Chodas, head of the Center for Studies of Near-Earth Objects in the Jet Propulsion Laboratory. He noticed that the Bennu asteroid – currently being examined by the NASZrys-REx space probe NASA – has a very low chance of hitting Earth in a few hundred years. "The one we will keep an eye on," he said, but added, "There are no serious asteroids."
The geometry of the Taurid stream is somewhat difficult to visualize. Imagine this as a ring around the sun, a kind of miniature asteroid belt, with a highly elliptical shape, so that the orbit takes the material roughly as close to the Sun as the first planet, Mercury, but also far beyond the Earth's orbit.
This material ring is roughly but not exactly on the same plane as the Earth's orbit. This means that the Earth exceeds the Taurid stream twice a year. The intersection in June crosses the Tauride material, moving away from the sun, and the intersection in October crosses the material moving towards the sun. That's why you can see the October Taurines when they hit the Earth's atmosphere. The June taurons are washed away by the sun, but can be detected by radar.
Boslough and Brown suggest that the secret to finding large objects among Beta Taurids is to look in a different direction – into the night sky, where the material would detach itself from Earth. Of course, he did not create shooting stars – this is the phenomenon of hitting meteors into the atmosphere – but with the help of telescopes, you could see any large object. When these great cosmic rocks move away from Earth, they will be concentrated in the geometry of the "disappearing point," the kind of "sweet spot" in the night sky, said Boslough.
If they are there, it means.