Initially, the asteroid 199145 (2005 YY128) was discovered in 2005 – its tentative designation in parentheses indicates exactly that. This binary “name” derives from rules developed by astronomers to catalog celestial bodies.
“When an asteroid approaching Earth is observed for the second time (it is in the second opposition), it gets a fixed number – in this case, it is 199145. In the future, those who discovered the body have the right to designate it. a more lyrical name: from mythology, in honor of a geographical object or person, excluding those currently living, ”explains Voropaev.
An asteroid cannot be immediately assigned a permanent number – this is due to an error in determining its orbit. Most asteroids are very faint and therefore can only be used for observation during opposition (or conflict) – when the Earth is between the Sun and the desired celestial body. At the moment, a well-lit star close to our planet and bright is not “dazzling” the observer. Then astronomers lose sight of the asteroid, and the observation time is too short to determine the exact orbit. A person will encounter a similar problem when trying to figure out exactly what direction a line is from two points close together. Therefore, in order not to catalog the wrong data, the corpse is added to it only after the second series of observations in the next contrast – which is happening now.
199145 (2005 YY128) is a near-Earth asteroid – but that doesn’t mean it’s consistently close to Earth or its orbit as it orbits the Sun. This asteroid’s orbit intersects with Earth’s orbit, so it is classified as Apollo, which poses a potential danger to humanity. At the same time, the perihelion 199145 (the closest point of the orbit to the Sun) orbits Mercury, and the apohelion (the farthest point of the celestial body from the Sun) is between the orbits of Mars and Jupiter. that is, the trajectory of its motion resembles a long ellipse, where it makes a full rotation in about two years or 774 days.
At the moment there is no information about the composition and structure of the asteroid, and even its diameter is known approximately – 500-800 meters. This is because from terrestrial telescopes (except the largest ones) it looks like a point light source – meaning it has no angular dimension, only brightness.
“Therefore, estimates of the size of the asteroid vary widely. We see its average luminosity and estimate its size based on the average albedo (reflectance) value of similar objects.
At the same time, the average albedo is the “average temperature in the hospital.” Some asteroids are very dark, almost pitch black, such as carbonaceous chondrites. Asteroids belonging to the Vesta group are almost white and very bright. As a result, astronomers start from the fact that the unknown object is approximately “grey”, and calculation using this methodology shows that the size of 199145 is approximately equal to 800 meters.
explain the astronomer.
It is believed that if the asteroid is “white” rather than “gray”, its size is around 400 meters, and if it is dark, it can reach a kilometer.
This diameter is considered too large for asteroids of this class – there should be several thousand among those approaching Earth. The fall of such an object to Earth would be a catastrophe comparable to the explosion of a powerful thermonuclear device. By comparison, the nineteen-meter and loose Chelyabinsk meteorite was able to break windows and damage roofs due to a single shock wave caused by hypersonic motion in the atmosphere.
asteroid damage calculator, created For informational purposes, Imperial College London points to a capacity of around 55,000 megatons of TNT if the current approach ends up falling into Earth’s sedimentary rocks.
This is about a thousand times the power of the Tsar Bomb, which was tested on Novaya Zemlya in 1961. After the fall, the crater would reach 10-14 kilometers in diameter, and seismic waves like earthquakes would raze fragile buildings even 100 kilometers away from the impact point.
But calculations show that 199145 will not threaten Earth in the near future.
“Preliminary calculations showed that in the foreseeable future – about 200 years (we are not looking further) – a dangerous approach to Earth is not foreseen. Moreover, the current approach at 4.6 million kilometers is the closest. So, after three revolutions in 2029, 199145 will approach 8.9 million kilometers from Earth, and in 2059 7 million kilometers from Earth. Everything else will be much further away,” he said.
To calculate the fate of this asteroid for thousands and millions of years, it will be necessary to observe it at least a few more contrasts, so that each new observation will reduce the error in the orbital prediction. This will also allow us to more accurately answer how 199145 formed. It has probably been in its current orbit for hundreds of millions of years, but could potentially have formed in the young solar system billions of years ago. In addition, its movement is affected by non-gravity factors, for example, the Yarkovsky effect. This is what astronomers call weak jet thrust due to uneven heating: one side takes heat from the Sun and, after turning in the other direction, emits photons into space. This effect is very weak, but when exposed over millions of years, it changes the trajectory significantly.
Observing 199145 without a telescope is useless – its apparent magnitude is about 13.8, which is less than that of Pluto at its peak brightness. Theoretically, such an object can be photographed with a good amateur telescope with an aperture of 20 centimeters or more, but currently 199145 is observed mainly at southern latitudes.