The object TB145 2015 was discovered for the first time in 2015 e brushed Earth a few days later, October 31, which coincided with the celebration of Halloween. The possibility was that, in addition, it had the shape of the dark sign that Harry Potter seen for the first time in the fourth book (or film) of the saga. The Voldemort brand is a skull from which a snake comes out, but in this case 2015 TB145 is just a skull that crosses the sky.view.
Although it will pass close to the Earth, it will be difficult to observe it with the naked eye and will not be so close 1,112 days ago – more than 3 years -, which is the time needed to meet again, that is, its orbital period. In this case it will go further, a million miles from us. However, at that time it passed to 486 thousand kilometers from the Earth or, on equal terms, 1.3 times the distance between the Moon and the Earth.
In reality "we know little" of this asteroid, says Javier Licandro, research coordinator in the Institute of Astrophysics of the Canary Islands (IAC). For example, we know its dimensions: 650 meters in diameterthat is, it has 109 meters more than the skyscraper One World Trace Center, raised in New York ground zero. Similar sizes have asteroids Ryugu and Bennu, which are currently studying space agencies Japanese and American, who will bring samples to Earth to study with Hayabusa 2 e Osiris-Rex.
And we also know something important, that it is not an asteroid but a comet. A subtle difference because it is difficult to distinguish sometimes, but important.
Although it is initially classified as an asteroid, everything indicates that it is not and that we are facing a "dormant or extinct comet" because of the "type of orbit" it has. What does this mean? "Comets are basically balls of ice, dust and stones," explains Licandro. Hipertextual. When they pass near the Sun, the researcher adds, the sublime ice, ie "passes from solid to gas".
"In this new state, it escapes and carries dust and produces the tail or comma that is seen in comets." Comets look very bright because they generate a kind of huge temporary atmosphere due to the water vapor expelled from the surface. It comes out when it's hot, but at the same time the dust comes out or comes back to the surface and that's it it forms a layer of dust that can cover the entire comet to the point of deactivating itThis means that the ice that remains below that layer of dust heats up enough to sublimate and produce the gas outlet, "explains the IAC researcher.
The researcher also states that "it moves very similar to comets", but it is not the only thing: "It is very black, and the comets are extremely dark, reflecting less than 5-6% of the light it receives". "The comet is like a very dirty snowball and covered with very dark dust. It has a high content of organic materials"However, the exact composition is unknown because" there is not much data on the spectrum or other ".
On the curious shape of the comet's skull that will pass on November 11, Licandro states that "it's really like someone looking at the clouds and saying they see a sheep, it is our imagination more than anything else".
Is it a danger to the Earth?
Astronomers catalog the asteroids and comets that pass close to the Earth, among other things, based on the chances they have of impacting our planet. 2015 TB145 is listed as "potentially dangerous", as underlined by Licandro. However, there is nothing to fear. This classification only means that "in the future or in the centuries it could clash, that is, the possibility of this happening is not zero, but it does not mean that it will happen either. Most likely, it will never collide, but it could happen in hundreds or thousands of years ", adds Licandro.
Do not worry because, in addition, scientists have very controlled this type of objects: "These objects they are particularly followed by the possibility of colliding with the Earth and since such a large object can cause a very considerable disasterLicandro explains, "An object like this could put an end to civilization as we know it," explains the IAC researcher, but it would be worse if it were larger: "One kilometer in diameter would cause extensive extensions that included our species" However, this this is not the case, so for the moment we do not have to worry about this hypothetical situation.
In summary, what we know of 2015 TB145 is short: we do not know its exact composition, but we know its diameter and it looks like an extinct comet. In 2015 it passed very close to the Earth, so it is listed as "potentially dangerous" and the astrophysicists have very controlled it, although it will not come so close to Earth in the coming decades – Their approach closer to us will not be until 2088 and even then it will be at a similar distance three years ago.
However, the approach of this November 11 will help researchers to study a little more and get more information about the call, informally, as a comet Halloween.
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