"Stars" fell from the sky in my sleep and fell to the bed of the old Canadian lady
The probability of a meteorite falling on the ground is very high, but the probability of hitting a person is extremely small
Our reporter Tang Fang
Tianwen Channel
A meteorite hit the side of his head in the middle of the night and was "caught" by the pillow.
Recently, Canada's Granny Ruth has become such a lucky person, and her experience has also been hot searched.
That night, a shooting star crossed the night sky of a Canadian province.
With a loud "boom", Grandma Ruth was awakened in her sleep, and she found that there was a big black stone on the pillow.
Grandma Ruth said afterwards that the "star" that fell from the sky may have a history of hundreds of millions of years, and that it had flown all the way from outer space to her pillow, so she planned to preserve the meteorite.
Where did the meteor come from?
Is there a high probability that it will fly to the earth and fall to the ground and become a meteorite?
Is there radiation from the meteorites picked up?
In this regard, a reporter from Science and Technology Daily interviewed Ping Jinsong, a researcher at the National Astronomical Observatory of the Chinese Academy of Sciences.
Meteorites fall to the ground every day
"Most people have never seen a meteorite, but in fact, the probability of a meteorite falling to the surface is very high." Ping Jinsong told reporters that some meteors will be burned out before they hit the ground, and some will fall to the ground. The ground becomes meteorites, micrometeorites or interstellar dust.
In April this year, an international scientific research cooperation organization announced a data that about 5,200 tons of interstellar dust fall to the earth every year.
"It can be said that interstellar dust falls to the ground almost every moment." Ping Jinsong added that the research team has collected interstellar dust in Antarctica for 20 years, ranging in diameter from 30 to 200 microns.
The true size of the micrometeorite is most likely the size of a mung bean.
"Micrometeorites range from a few tens of microns to several millimeters, and the amount of falling to the ground is less than that of interstellar dust, but they are almost always happening, accounting for most of the total mass of meteorites." Ping Jinsong said.
Meteorites ranging from a few millimeters to hundreds of meters in diameter seem to be rare, but they fall to the surface every day.
Ping Jinsong said that common meteorites include olivine-iron or iron-nickel meteorites, as well as various rock or rock-soil meteorites. The "picked up" meteorites can be stored in a dry, normal temperature, and away from the magnetic field (magnet) environment to avoid deterioration. Its radiation intensity is lower than that of the ground environment, and even lower than that of a newly renovated reinforced concrete house.
What's interesting is that meteorites almost always "avoid" human beings and fall on the surface.
Because billions of people on the planet, even if they are outdoors, are tiny compared to the total surface area of the planet.
Very few people were hit by meteorites directly, but incidents of meteorites breaking roofs and falling into residential courtyards are reported every few years.
Even so, the probability of a meteorite hitting a person is much smaller than that of a direct lightning hit.
Mainly from comets and asteroid belts
Where do these meteors rushing towards the earth come from?
The answer is comets, near-Earth asteroids and asteroid belts.
Ping Jinsong explained that the earth's orbit around the sun has crossed dozens of comet or asteroid remnants.
The meteoroids in the relic zone are similar to sand grains, weighing less than 1 gram. When the earth passes through the relic zone, many meteoroids are attracted by the earth’s gravity and enter the earth’s atmosphere at speeds ranging from 11 kilometers to 72 kilometers per second and become meteors. .
In addition, there are more than a dozen banded trails of comets, which have just passed the orbit of the earth around the sun.
A large number of asteroids and dust in the comet's band-like trail will also be captured by the earth's gravity, and a large number of them will break into the earth's atmosphere, thus forming a meteor shower.
"Therefore, meteors are mainly composed of dust, ice, and ice dust particles in the trail of comets. The solid particles in the latter two contain volatile matter such as water, carbon monoxide, and carbon dioxide. In addition, there are also meteors that are rocky. Rock masses, rock-iron mixtures, or iron-nickel metal bodies after the decomposition of asteroids." Ping Jinsong said.
If you want to see the meteor shower, please refer to the meteor shower forecast
Ping Jinsong revealed that meteor showers occur on the earth almost every month, and it is best to watch the meteors in a clear, non-full moon, and far away from big cities in the evening to early morning.
The splendid meteors in the night sky occur at an altitude of 80-120 kilometers from the surface, and the slowest meteors are also 10 times faster than ordinary bullets out of the barrel.
Generally speaking, when a meteor shower occurs, more than ten meteors can be seen every hour in a relatively large sky area.
There have also been large-scale meteor showers in history, hundreds to thousands of meteors can be seen every hour.
Ping Jinsong said that now the occurrence and best observation locations of meteor showers and the best observation time periods can be forecasted. Usually, the annual meteor shower calendar of the International Astronomical Society or the International Meteor Organization can be used to obtain more accurate forecast information.
Usually, astronomers name the meteor shower after the constellation of the sky area where the meteor radiant point is located. The major meteor shower events corresponding to the next 10-20 years include:
In January, the quadrant meteor shower has a flow of about 40 per hour, the color is blue, and the speed is fast, about 40 kilometers per second.
The Lyra meteor shower in April is bright and rapid, about 48 kilometers per second.
Meteor shower η Aquarius in May, the density of meteors is high, and the flow rate is not very stable. The minimum flow rate is tens of particles per hour, and the maximum flow rate is hundreds of particles per hour.
In June, the Lyra meteor shower has a low flow rate. Even at its peak, the flow rate is only about 10 per hour.
In July, the delta Aquarius meteor shower has a flow of about 20 per hour at its peak, showing a bright yellow color, with a medium speed, about 40 kilometers per second.
From July to August, the Capricorn meteor shower has a flow of about 15 per hour at its peak, and the speed is relatively slow, only about 25 kilometers per second.
The Perseid meteor shower in August has a high flow rate, with a peak flow rate of about 60 per hour.
In October, the Draco meteor shower has a low flow rate of only about 10 per hour.
From October to November, the Orionids meteor shower has a flow of about 20 per hour and a relatively fast speed, about 66 kilometers per second.
In November, the Leo meteor shower has a peak flow in about 33 years, and the flow can reach hundreds of stars per hour during the peak period.
The Gemini meteor shower in December is the most stable and colorful meteor shower of the year, with a peak flow of hundreds of meteors per hour.
In December, the Ursa Minor meteor shower has a flow of only about 10 per hour and a speed of about 33 kilometers per second.