There are hundreds of millions of asteroids in our solar system, which means that new asteroids are discovered quite often. It also means that close encounters between asteroids and Earth are fairly common. Some of these close encounters end with the asteroid colliding with Earth, sometimes with serious consequences.
A recently discovered asteroid, named 2023 BU, made the news because it passed so close to Earth today.
Discovered on January 21 by amateur astronomer Gennadiy Borisov in Crimea, 2023 BU passed only about 3,600 kilometers (near the south pole of South America) six days later, on January 27.
That distance is only slightly more than the distance between Perth and Sydney, and only about 1% of the distance between our Earth and Moon.
This asteroid also passes through the region of space that contains a significant proportion of man-made satellites orbiting the Earth.
All of this makes 2023 BU the fourth-closest known asteroid to hit Earth, ignoring those that have impacted the planet or our atmosphere.
How to judge 2023 BU as an asteroid and a threat? 2023 BU is unremarkable, except that it passes too close to Earth. The diameter of the asteroid is estimated at only 4–8m, which is at the small end of the asteroid size range.
There may be hundreds of millions of such objects in our solar system, and it is possible that 2023 BU has come close to Earth many times before over the millennia. Until now, we were ignorant of reality.
In context, an asteroid with a diameter of 4 meters will collide with Earth every year on average, and an asteroid with a diameter of 8 meters every 5 years or so. ozone. They create spectacular fireballs and some asteroids can fall to the ground as meteors.
Now that 2023 BU has been detected, its orbit around the Sun can be estimated and future Earth visits predicted. It is estimated that there is a 1 in 10,000 chance that the 2023 BU will impact Earth sometime between 2077 and 2123.
So we have nothing to fear about 2023 BU or any of the millions of similar objects in the Solar System.
Asteroids need to be larger than 25m in diameter to pose any significant risk to life upon impact with Earth; To challenge the existence of civilization, they need to be at least a kilometer in diameter.
It is estimated that there are fewer than 1,000 such asteroids in the Solar System and could impact Earth every 500,000 years. We know about more than 95 percent of these subjects.
Will more asteroids pass closer? 2023 BU is the fourth closest asteroid pass ever recorded. Three closer passes are of very small asteroids discovered in 2020 and 2021 (2021 UA, 2020 QG and 2020 VT).
Asteroid 2023 BU and countless other asteroids have passed very close to Earth in the nearly 5 billion years of the Solar System’s existence, and this situation will continue into the future.
What has changed in recent years is our ability to detect asteroids of this size, so that any threat can be described. The fact that an object about 5m in size can be detected thousands of kilometers away by a very dedicated amateur astronomer shows that the technology to make important astronomical discoveries is within the grasp of the technology. they. This is very interesting.
Amateurs and professionals alike can further explore and classify objects so that threat analysis can be performed. Another very interesting development took place last year, by the Dual Asteroid Redirection Test (DART) mission, which successfully collided a spacecraft with an asteroid and changed direction. its.
DART offers a reasonable concept of redirecting an asteroid out of the direction of impact with Earth if threat analysis identifies a severe risk with sufficient warning.
