On June 30, 1908, an object the size of a residential building collapsed from the sky and exploded in the atmosphere over Siberia. The Tunguska event named after a river pushed trees for 800 square kilometers. 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 washes out the "shooting stars" visible during the nightly meteor shower later in the year.
A new computation by Mark Boslough, a physicist at Los Alamos National Laboratory, shows the tree The fall pattern in Siberia matches an asteroid that originates 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 – and 2019 will be a year like that. The scientists claim that it represents the potentially richest amount of incoming material since 1975, when seismometers left by Apollo astronauts on the moon experienced an increase in impacts during the Taurid flock.
"If the Tunguska object was a member of a Beta Taurid River … Then the last week in June 2019 will be the next opportunity, with a high probability for Tunguska-like collisions or near-misses," said her 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 such an event at or near the Tunguska Jubilee next year. "19659009" To be clear, no one says that June should be declared a helmet month for the National Helmet, and even if the Taurid stream contains a greater number of Tunguska-class objects, the likelihood of having one on Earth remains space rocks are rarely as close as our moon.
Experts have a simple explanation for this: Space is big, it's much easier to miss the Earth than to hit it, of course it can happen, and this was the case in 2013, when an object smaller than the Tunguska impactor crashed into the atmosphere near Chelyabinsk in Russia, producing a fireball and a shockwave that shattered windows and injured more than 1,000 people.
In the entire recorded history of humanity, the number of people killed by asteroid impacts is zero.
"This should not stop you at night," s Brown acted.
Boslough and Brown do not know whether an "elevated" population of relatively large asteroids is actually lurking in the Beta Taurids. This is a guess.
Boslough puts the danger of asteroidal effects in the right perspective: "It is one of those risks with very low probability, but potentially high risk, that is difficult to quantify and hard to talk about. The likelihood of many people dying from an asteroid impact is great, super low, but it's not zero. He adds, "There are so many other dangers that pose a greater risk.
Astronomer Amy Mainzer, who hunts Asteroids at NASA's Jet Propulsion Laboratory, is chief investigator of the proposed Near-Earth Object Camera (NEOcam), an infrared space telescope that scans earth's Earth orbit for potentially dangerous asteroids more than 90 percent of the objects should be large enough cause a catastrophe on a global scale.
But if you shut down the size scale, the census is much more patchy. 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 note: The large asteroids identified so far pose no significant threat to the Earth as far as a human can see
"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. "The ones we will keep an eye on," he said, adding, "Asteroids are not particularly affected."
The geometry of the taurid 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 could be used to see large objects. As these great 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, that is.  Continue reading:
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