On June 30, 1908, an object the size of a residential building jumped out of the sky and exploded in the atmosphere over Siberia.
The Tunguska event named after a river squeezed trees for 800 square miles. It occurred in one of the least populated areas of Asia and nobody was killed or injured. However, the Tunguska airburst is the most powerful impact event in recorded human history and remains puzzling as scientists do not know the origin of the object or know if it was an asteroid or a comet.
One hypothesis: That was a Beta Taurid.
The Taurids are meteor showers that occur twice a year, in late June and late October or early November. The June meteors are the betas. They hit during the day when sunlight flushes out the "shooting stars" that become visible later in the year during the nocturnal meteor shower.
A new computation by Mark Boslough, a physicist at Los Alamos National Laboratory, shows the tree The fall pattern in Siberia matches an asteroid from the same area in the sky as the Taurid meteorite swarm. Boslough and physicist Peter Brown of the Western University in London, Ontario, gave a talk at the American Geophysical Union autumn conference in Washington this month demanding a special observing campaign to search for Tunguska class or larger objects in June which are nestled in West Virginia Taurids.
In a few years, Earth will be near the densest heap of material in the Taurid Current ̵
… then the last week in June 2019 will be the next opportunity, with a high probability for Tunguska-like collisions or near-misses, "stated their AGU presentation.
" While we predict no further Tunguska airburst, An increased population of small NEOs [near-Earth objects] in the Beta Taurids would increase the likelihood of another such event on or near the Tunguska Jubilee next year, "they concluded.
To be unclear, no one says that Even though there may be an "increased" number of Tunguska-class objects in the Taurid stream, the likelihood of one hitting the ground remains very low close like our moon.
Experts have a simple explanation for this: Space is big, it's much easier to miss Earth than to hit it Of course, it can happen, and this happened in 2013, when an object smaller than the Tunguska impactor crashed into the atmosphere near Chelyabinsk, Russia, causing a fireball and a shockwave that shattered windows and More than 1,000 people injured.
Throughout the recorded history of humanity, the number of people killed by asteroid impacts is zero.
"This should not be used to stay busy at night," Brown said. Boslough and Brown do not know if there is actually an "elevated" population of relatively large asteroids lurking in the Beta Taurids. This is a guess.
Boslough puts the danger of asteroid impacts in the right perspective: "It is one of those very low-probability, but potentially high-consequence types that is difficult to quantify and hard to talk about – the likelihood of a lot of people getting involved dying asteroid hit is awesome, super low, but not zero. "He adds," There are so many other dangers that pose a greater risk. "
Astronomer Amy Mainzer, who hunts for asteroids at NASA's Jet Propulsion Laboratory and is the principal investigator of the proposed Near-Earth Object Camera (NEOcam), an infrared camera, according to a space telescope that surveys Earth's Earth orbit for potentially dangerous asteroids Researchers have found that more than 90 percent of the objects are large enough to cause a catastrophe of global proportions. Only about 30 percent of the 140-meter (460-foot) diameter midsize objects were discovered. She said that only about 1 percent of the objects were found to be the size of the Tunguska impactor, which had a diameter of about 40 meters. She said she welcomed the idea of a special effort to look for objects during the taurid swarm in June.
Another reassuring remark: The large asteroids identified so far are not a significant threat to the Earth as far as we can tell
"There are no objects in our catalog that have a significant impact probability over the next 100 years" said Paul Chodas, Manager of the Near-Earth Object Studies Center at the Jet Propulsion Laboratory. He found that the asteroid Bennu – currently being studied by NASA's Osiris REx spacecraft – has a very small chance of hitting Earth in a few hundred years. "What we'll have an eye on," he said, adding, "Asteroids are not very important."
The geometry of the tauride stream is somewhat difficult to visualize. Think of it as a ring around the sun, a sort of miniature asteroid belt with a very elliptical shape, where orbit brings the material about as close to the sun as the first planet Mercury, but also far beyond Earth orbit ,
This ring of material is approximately, but not exactly on the same plane as Earth orbit. That is, the earth traverses the taurid stream twice a year. The June Crossing crosses taurides material that moves away from the sun, and the October Crossing crosses material that approaches the sun. That's why you can see the October Taurids when they hit the Earth's atmosphere. The June Taurids are washed out by the sunshine, but can be detected by the radar.
Boslough and Brown suggest that the secret to finding large objects under the Beta Taurids is to look the other way – to the night sky, where the material would stand, away from the earth. Of course, it would not create shooting stars – this is a phenomenon in which meteors hit the atmosphere – but telescopes can be used to see large objects. As these large space rocks move away from Earth, they are concentrated in a "vanishing point" geometry, a sort of "sweet spot" in the night sky, Boslough said.
If they are there, it is. 19659023] / *