I was preparing for my early morning class as early as 2025. January, when I received a report of an asteroid called 2024. He said the likelihood that it could hit the ground was unusually high.
Since defending the land from unexpected invaders such as asteroids is part of my competence, I immediately started getting questions from my students and colleagues about what was going on.
When scientists notice an asteroid whose trajectory can take him close to the ground, they often observe and calculate the likelihood that it may face our planet. With more monitoring data, they depict better what can happen.
Just having more data points early, scientists’ forecasts don’t make better. They need to continue to follow the asteroid as it moves through space to better understand their trajectory.
After a few months of thinking about the event, I wondered whether scientists could have been a better way to communicate about the risks of society. We received accurate information, but as I was given the questions, it was not always enough to understand what it really meant.
Numbers change every day
2024. The diameter of the asteroid is about 196 feet (60 meters)-the length of the building is about 15 floors.
January The report reported that the probability of the effect of asteroid exceeds 1%. The probability of exposure describes how likely a dangerous asteroid strikes the Earth. For example, if the likelihood of an effect is 1%, it means that 1 in 100 cases reach the ground. One in 100 is rare, but it is still too close to be convenient if you are talking about the likelihood of a collision that can devastate the land.
However, over time, other observations and analyzes have revealed almost zero the possibility that this asteroid is facing Earth.
After the original report in January. February 18 The probability of exposure was constantly increased to 3.1%, but on 19 February. Decreased to 1.5%. Then the probability of exposure was constantly decreasing until February 24th. It reached 0.004%. From June 15 It has less than 0.0000081%.
However, although the likelihood of Earth’s struck to Earth, the likelihood of an asteroid that hit the moon began to increase. February 24th This increased to 1.7%. From April 2 This is 3.8%.
If it hit the moon, some materials of this collision can reach the Earth. However, these materials would burn when it entered the thick atmosphere of the Earth.
Probability of exposure
To see if an impending object can hit the ground, researchers learn what the asteroid orbit looks like using a technique called astrometry. This technique can accurately determine the orbit of the object to the uncertainty of only a few kilometers. However, astrometry requires accurate monitoring data taken for a long time.
Any uncertainty of the orbit of an object is caused by options for the intended solution. Instead of one accurate orbit, the calculation usually gives scientists a cloud of its possible orbit. The ellipse covering these areas is called an error in the ellipse.
The likelihood of exposure describes how many orbit predictions in this ellipse got into the ground.
In addition to sufficient monitoring data, the uncertainty of orbit is high, so the ellipse is usually high. In a large ellipse, the ellipse is more likely to “accidentally cover the Earth – even if the center is on the planet. So, even if an asteroid eventually misses the Earth, its mistakes in the ellip will still be a planet until scientists collect sufficient data to narrow uncertainty.
As the level of uncertainty is affected, the ellipse shrinks. Thus, when the Earth is a small mistake inside the ellipse, the chance of impact can become higher than when it is a major mistake inside the ellipse. When the mistake of the ellipse is sufficiently shrinking that it no longer pulls the ground, the likelihood of exposure is significantly reduced. This happened in 2024.
When an error ellipse shrinks, the likelihood of an asteroid that strikes the earth descends or rises if it ends with the ground. Toshi Hirabayashi
The likelihood of exposure is one practical value that offers a meaningful insight into the threat of influence. However, simply using the likelihood of exposure without any context may not provide significant guidelines to the public, as we have seen with 2024.
Adherence and wait for more data to revise the collision forecast, or by introducing a new metric to evaluate the effect on Earth, are alternative action courses to provide people with better future threats guidelines before adding confusion and fear.
This article has been published from a conversation, non -profit, independent news organizations that provide you with facts and reliable analysis to help you give meaning to our complex world. It wrote: Toshi Hirabayashi, Institute of Georgia Technology
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I studied planetary defense, especially as the past, ongoing and future small body missions. I was part of NASA/DART mission. I am currently part of the NASA/Lucy Mission and ESA/Hera Mission. I am also on the Hayabusa2#team headed by Japanese Aviation and Space Exploration Agency (JAXA) as part of international cooperation. I have no relationship with Jaxa.