Impressive comets that have ever appeared in the earth's sky. The most famous comets Help Which comet will fly by in the near future
Scientists argue that not even the celestial body itself poses a special risk, but the gas and dust plume of the comet Hulk, which will bring climate change, typhoons, tornadoes and other catastrophic consequences for human life.
The fact that a dangerous comet will approach the Earth on August 7, 2018 will be known to all the inhabitants of the Earth, since it will be possible to see it like the brightest star in the night sky with the naked eye. Comet Hulk is twice the size of the planet Jupiter, and its greenish-blue color will illuminate the sky with an unusual radiance. It will be possible to observe the unique phenomenon from Tuesday, August 7 to Thursday, August 16, 2018, when the visibility of parts of the comet will be at its maximum.
Initially, the comet Hulk did not have a tail, and scientists watched its movement through the sky through a telescope, fearing for life on our planet. However, in mid-July 2018, the incredible happened: an unknown force literally tore the comet into several pieces!
On the one hand, this guaranteed that in August 2018 the End of the World would not take place due to a collision with a dangerous comet. But after a sharp rupture of the celestial body, a gas and dust plume was formed that will attack the Earth throughout the last month of summer.
According to experts, the 2018 asteroid will bring with it new weather anomalies: tornadoes and tornadoes are expected in the United States, and prolonged cyclones will sweep across Europe, when incredible heat will abruptly give way to cold weather. High-precision equipment will begin to fail, sudden accidents are possible at power plants, and passenger aircraft pilots will lose control of aircraft.
The news about the 2018 meteorite speaks in favor of the fact that the Hulk comet was supposed to be a harbinger of the end of the world and become a formidable warning that the End of the World in 2018 will come because of the planet Nibiru.
The comet that has disintegrated into parts poses an even greater threat to humanity than before due to the fact that the substances contained inside the nucleus of the Hulk comet have escaped. Russian researcher of cometary meteorites, astronomer Evgeny Dmitriev, said that the gas and dust cloud is 260 thousand kilometers in diameter. Ionized plasma can only be partially neutralized by the atmosphere of the planet Earth, but even this will be enough for residents of different parts of the world to observe unusual phenomena in the atmosphere, which are often mistaken for UFOs.
In 2009, Robert McNaught opened Comet C/2009 R1, which is approaching the Earth, and in mid-June 2010, the inhabitants of the northern hemisphere will be able to see it with the naked eye.
Comet Morehouse(C / 1908 R1) - a comet discovered in the USA in 1908, which was the first of the comets to be actively studied using photography. Amazing changes were seen in the structure of the tail. During the day of September 30, 1908, these changes occurred continuously. On October 1, the tail broke off and could no longer be observed visually, although a photograph taken on October 2 showed three tails. The rupture and subsequent growth of the tails occurred repeatedly.
Comet Tebbutt(C/1861 J1) - A bright comet, visible to the naked eye, was discovered by an Australian amateur astronomer in 1861. The Earth passed through the comet's tail on June 30, 1861.
Comet Hyakutake(C/1996 B2) is a large comet that reached magnitude zero in March 1996 and produced a tail estimated to be at least 7 degrees long. Its apparent brightness is largely due to its proximity to the Earth - the comet passed from it at a distance of less than 15 million km. The maximum approach to the Sun is 0.23 AU, and its diameter is about 5 km.
Comet Humason(C / 1961 R1) - a giant comet, discovered in 1961. Its tails, despite being so far from the Sun, still extend 5 AU in length, which is an example of unusually high activity.
Comet McNaught(C/2006 P1), also known as the Great Comet of 2007, is a long-period comet discovered on August 7, 2006 by British-Australian astronomer Robert McNaught and has become the brightest comet in the last 40 years. Residents of the northern hemisphere could easily observe it with the naked eye in January and February 2007. In January 2007, the comet's magnitude reached -6.0; The comet was visible everywhere in daylight, and the maximum length of the tail was 35 degrees.
Every year on August 12, meteorites rapidly trace the sky with bright fiery streaks all night long, burning up in the middle layers of the atmosphere. This fiery performance is called the Perseus meteor shower. Moving in orbit, the Earth crosses the meteor shower - the plume of a comet making its way around the Sun.
What are comets?
Comets, like stone asteroids, are, so to speak, waste products after the formation of the Sun, planets and their satellites. Comets are composed mostly of ice with inclusions of small rocks and dust. For most of their lives, comets graze on vast desert pastures at the periphery of the solar system.
The most distant planet in the solar system, Pluto, is located at a distance of 5.8 billion kilometers from the Sun. A cluster of comets called the Kuiper Belt is located 480 million kilometers further than Pluto. Another similar cluster - the Oort Cloud - is 160 billion kilometers away from the Sun. In fact, the Oort Cloud is not a cloud, but a huge cluster of trillions of comets, these comets roam the universe in different directions, like cows in a grazing herd. It is believed that the Oort Cloud surrounds the solar system as a huge halo.
Interesting fact: Comets make one revolution around the Sun every one million years on average.
Evidence for cometary clusters
Proving the existence of cometary clusters is very difficult. And that's why. Even if you fly in a rocket through the Oort Cloud, you can not meet a single comet during the trip. They are separated by a distance of millions and billions of kilometers. Since comets are far from the Sun, they are very weakly lit and look almost as dark as the outer space surrounding them. Comets far from the Sun do not have tails attributed to them. Their color is red - brown, the size is about two kilometers. In a word, they look like big dirty icebergs.
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Interesting facts about space
Travel of comets
The ugly face of the comet is transformed when it leaves the herd and approaches the Sun. At this moment, the comet undergoes an instantaneous transformation. It stretches across the night sky in a long shining strip, bringing people to horror and delight. What force drives a comet out of the Oort Cloud? Naturally, gravity. Here's how it happens. The sun is rapidly flying in space and dragging behind it a bunch of planets, their satellites and comets. The path of the Sun lies among the stars of the Milky Way. A herd of comets carried by the Sun sometimes passes close to another star. The force of its gravity produces a disturbance in the Oort Cloud, shifting comets from their usual positions.
In our solar system, along with the planets and their satellites, there are space objects that are of great interest in the scientific community and are popular among the inhabitants. A place of honor in this series is rightfully occupied by comets. It is they who add brightness and dynamics to the solar system, turning near space into a testing ground for a short time. The appearance of these space wanderers in the sky is always accompanied by bright astronomical phenomena that even an amateur astronomer can observe. The most famous space guest is Halley's comet, a space object that regularly visits near-Earth space.
The last appearance of Halley's comet in our near space was in February 1986. She appeared for a short moment in the sky in the constellation of Aquarius and quickly disappeared into the halo of the solar disk. During the passage of perihelion in 1986, the space guest was in the field of view from the Earth and a short period could be observed. The next visit of the comet should take place as early as 2061. Will the usual schedule for the appearance of the most famous space visitor after 76 years be violated, will the comet fly back to us in all its glory and splendor?
When did Halley's comet become known to man?
The frequency of occurrence of known comets in the solar system does not exceed 200 years. The visits of such guests have always evoked an ambiguous reaction in a person, causing concern to some unenlightened people and delighting the scientific fraternity.
For other comets, visits to our solar system are rare. Such objects fly into our near space with a frequency of more than 200 years. It is not possible to calculate their exact astronomical data due to their rare occurrence. In both cases, humanity has constantly dealt with comets throughout its existence.
For a long time, man was in the dark about the nature of this astrophysical phenomenon. Only at the beginning of the 18th century was it possible to initiate a systematic study of these most interesting space objects. Halley's comet, discovered by the English astronomer Edmund Halley, became the first celestial body about which it was possible to obtain reliable information. This became possible due to the fact that this space wanderer is clearly visible to the naked eye. Using the observational data of his predecessors, Halley was able to identify a space guest who had visited the solar system three times before. According to his calculations, the same comet appeared in the night sky in 1531, in 1607 and in 1682.
It is today that astrophysicists, using the nomenclature of comets and the available information about their parameters, can confidently say that the appearance of Halley's comet was noted in the earliest sources, approximately in 240 BC. Judging by the descriptions available in the Chinese chronicles and in the manuscripts of the Ancient East, the Earth has already met this comet more than 30 times. The merit of Edmund Halley lies in the fact that it was he who managed to calculate the periodicity of the appearance of a space guest and quite accurately predict the next appearance of this celestial body in our night sky. According to him, the next visit was to take place in 75 years, at the end of 1758. As expected by the English scientist, in 1758 the comet once again visited our night sky and by March 1759 flew within sight. This was the first predicted astronomical event associated with the existence of comets. From that moment on, our constant celestial guest was named after the famous scientist who discovered this comet.
On the basis of long-term observations of this object, the dates of its subsequent appearances are approximately drawn up. Despite the fact that in comparison with the transience of human life, the period of revolution of Halley's comet is quite long (74-79 Earth years), scientists are always looking forward to the next visit of the space wanderer. In the scientific community, it is considered great luck to observe this enchanting flight and the astrophysical phenomena that accompany it.
Astrophysical features of the comet
In addition to its rather frequent appearance, Halley's comet has interesting features. This is the only well-studied cosmic body that, at the moment of approach to the Earth, moves with our planet on a collision course. The same parameters are observed in relation to the motion of other planets in our star system. Hence, there are quite ample opportunities for observing a comet that makes its flight in the opposite direction along a highly elongated elliptical orbit. The eccentricity is 0.967 e and is one of the highest in the solar system. Only Nereid, a moon of Neptune, and the dwarf planet Sedna have orbits with such similar parameters.
The elliptical orbit of Halley's comet has the following characteristics:
- the length of the semi-major axis of the orbit is 2.667 billion km;
- at perihelion, the comet moves away from the Sun at a distance of 87.6 million km;
- during the passage of Halley's comet near the Sun at aphelion, the distance to our star is 5.24 billion km;
- the comet's orbital period according to the Julian calendar averages 75 years;
- the speed of Halley's comet in orbit is 45 km/s.
All the above data on the comet became known as a result of observations made over the past 100 years, from 1910 to 1986. Due to the large elongation of the orbit, our guest flies past us at a huge oncoming speed - 70 kilometers per second, which is an absolute record among the space objects of our solar system. Halley's comet of 1986 provided the scientific community with a lot of detailed information about its structure and physical characteristics. All data obtained was obtained by direct contact of automatic probes with a celestial object. Research was carried out with the help of the Vega-1 and Vega-2 spacecraft, specially launched for a close acquaintance with the space guest.
Automatic probes made it possible not only to obtain information about the physical parameters of the nucleus, but also to study in detail the shell of a celestial body and get an idea of what the tail of Halley's comet is.
In terms of its physical parameters, the comet was not as large as previously thought. The size of an irregularly shaped cosmic body is 15x8 km. The greatest length is 15 km. with a width of 8 km. The mass of the comet is 2.2x1024 kg. By its size, this celestial body can be equated to medium-sized asteroids wandering in the space of our solar system. The density of the space wanderer is 600 kg/m3. For comparison, the density of water in the liquid state is 1000 kg/m3. Data on the density of a comet's nucleus vary depending on its age. The latest data is the result of observations made during the last visit of the comet in 1986. It is not a fact that in 2061, when the next arrival of a celestial body is expected, its density will be the same. The comet is constantly losing weight, collapsing, and may eventually disappear.
Like all space objects, Halley's comet has its own albedo of 0.04, comparable to the albedo of charcoal. In other words, the nucleus of a comet is a rather dark cosmic object with a weak surface reflectivity. Sunlight barely reflects off the comet's surface. It becomes visible only due to its rapid movement, which is accompanied by a bright and spectacular effect.
During its flight through the expanses of the solar system, the comet is accompanied by the Aquarids and Orionids meteor showers. These astronomical phenomena are natural products of the destruction of the comet's body. The intensity of both phenomena can increase with each successive passage of the comet.
Versions about the origin of Halley's comet
In accordance with the accepted classification, our most popular space guest is a short-period comet. These celestial bodies are characterized by a small inclination of the orbit with respect to the axis of the ecliptic (only 10 degrees) and a short period of revolution. As a rule, such comets belong to the Jupiter family of comets. Against the background of these space objects, Halley's comet, like other similar space objects, stands out strongly for its astrophysical parameters. As a result, such objects were assigned to a separate, Halley type. At the moment, scientists could detect only 54 comets of the same type as Halley's comet, which in one way or another visit near-Earth space throughout the entire existence of the solar system.
There is an assumption that such celestial bodies were previously long-period comets and moved to another class only due to the influence of the force of attraction of the giant planets: Jupiter, Saturn, Uranus and Neptune. In this case, our current regular guest could have formed in the Oort cloud - the out-of-bounds region of our solar system. There is also a version about a different origin of Halley's comet. The formation of comets is allowed in the boundary region of the solar system, where trans-Neptunian objects are located. In many astrophysical parameters, small bodies in this region are very similar to Halley's comet. We are talking about the retrograde orbit of objects, strongly reminiscent of the orbit of our space guest.
Preliminary calculations showed that the celestial body that comes to us every 76 years has existed for more than 16,000 years. At least the comet has been moving in its current orbit for quite some time. It is not possible to state whether the orbit was the same for 100-200 thousand years. A flying comet is constantly influenced not only by the forces of gravity. Due to its nature, this object is strongly affected by mechanical stress, which in turn causes a reactive effect. For example, when a comet is at aphelion, the sun's rays heat up its surface. In the process of heating the surface of the core, sublimating gas flows arise, acting like rocket engines. At this moment, the comet's orbit fluctuates, affecting the deviations in the period of revolution. These deviations are clearly visible already at perihelion and can be 3-4 days.
Soviet robotic spacecraft and vehicles of the European Space Agency during their trip to Halley's comet in 1986 almost missed. Under terrestrial conditions, it turned out to be impossible to predict and calculate possible deviations in the period of revolution of the comet, which caused oscillations of a celestial body in orbit. This fact confirmed the version of scientists that the period of revolution of Halley's comet may change in the future. In this aspect, the composition and structure of comets become interesting. The preliminary version that these are huge blocks of cosmic ice is refuted by the long existence of comets that have not disappeared or evaporated in outer space.
Composition and structure of a comet
The nucleus of Halley's comet was first studied at close range by automatic space probes. If earlier a person could observe our guest only through a telescope, viewing her at a distance of 28 06 AU. That is, now the pictures were obtained from a minimum distance of just over 8000 km.
In fact, it turned out that the nucleus of a comet is relatively small and in appearance resembles an ordinary potato tuber. Examining the density of the core, it becomes clear that this cosmic body is not a monolith, but is a pile of fragments of cosmic origin, closely connected by gravitational forces into a single structure. A giant stone block does not just fly in outer space, tumbling in different directions. The comet has a rotation, which, according to various sources, is 4-7 days. Moreover, the rotation is directed towards the movement of the comet in orbit. Judging by the images, the core has a complex relief, which includes depressions and hills. A crater of cosmic origin was even discovered on the surface of the comet. Even despite the small amount of information obtained from the images, it can be assumed that the comet's nucleus is a large fragment of another large cosmic body that once existed in the Oort cloud.
The comet was first photographed in 1910. At the same time, data were obtained from a spectral analysis of the composition of our guest's coma. As it turned out, during the flight, as it approaches the Sun, volatile substances, represented by frozen gases, begin to evaporate from the heated surface of a celestial body. Vapors of nitrogen, methane and carbon monoxide are added to the water vapor. The intensity of emission and evaporation leads to the fact that the size of the coma of Halley's comet exceeds the size of the comet itself by a thousand times - 100 thousand km. against 11 km of average size. Together with the evaporation of volatile gases, dust particles and small fragments of the comet's nucleus are released. Atoms and molecules of volatile gases refract sunlight, forming the effect of fluorescence. Dust and large fragments scatter reflected sunlight into outer space. As a result of ongoing processes, the coma of Halley's comet is the brightest element of this celestial body, which ensured its good visibility.
Do not forget about the comet's tail, which has a special shape for a comet and is its trademark.
Three types of comet tails should be distinguished:
- type I comet tail (ionic);
- comet tail type II;
- type III tail.
Under the influence of the solar wind and radiation, the ionization of the substance that creates the coma occurs. Charged ions under the pressure of the solar wind are drawn into a long tail, the length of which exceeds hundreds of millions of kilometers. The slightest fluctuations in the solar wind or a decrease in the intensity of solar radiation leads to a partial tail break. Often, such processes can lead to the complete disappearance of the tail of a space wanderer. Astronomers observed this phenomenon with Halley's comet in 1910. Due to the huge difference in the speed of movement of charged particles that make up the comet's tail, and the orbital speed of a celestial body, the direction of development of the comet's tail is located strictly in the opposite direction from the Sun.
As for solid fragments, cometary dust, the influence of the solar wind is not so significant here, so the dust spreads at a speed obtained as a result of a combination of the acceleration imparted by the pressure of the solar wind to the particles and the initial orbital velocity of the comet. As a result, the dust tails lag far behind the ion tail, forming separate type II and III tails directed at an angle to the direction of the comet's orbit.
In terms of their intensity and frequency of ejection, the dust tails of a comet are a short-term phenomenon. If the ion tail of a comet, fluorescing, gives a violet glow, then the dust tails of types II and III have a reddish tint. Our guest is characterized by the presence of tails of all three types. Astronomers are familiar with the first two quite well, while the tail of the third type was noticed only in 1835. On its last visit, Halley's comet rewarded astronomers with the opportunity to observe two tails: the first and second types.
Analysis of the behavior of Halley's Comet
Judging by the observations made during the last visit of the comet, the celestial body is a fairly active space object. The side of the comet facing the Sun at a certain moment is a boiling source. The temperature on the surface of the comet facing the Sun varies in the range of 30-130 degrees with a plus sign on the Celsius scale, while the temperature on the rest of the comet's nucleus drops to below 100 degrees. Such a discrepancy in temperature readings speaks in favor of the fact that only a small part of the comet's nucleus has a high albedo and can heat up quite strongly. The remaining 70-80% of its surface is covered with a dark substance and absorbs sunlight.
Such studies have suggested that our bright and dazzling guest is actually a lump of dirt mixed with cosmic snow. The main mass of cosmic gases is water vapor (more than 80%). The remaining 17% are carbon monoxide, particles of methane, nitrogen and ammonia. Only 3-4% is carbon dioxide.
As for cometary dust, it mainly consists of carbon-nitrogen-oxygen compounds and silicates, which form the basis of the terrestrial planets. The study of the composition of the water vapor emitted by the comet put an end to the theory of the cometary origin of the Earth's oceans. The amount of deuterium and hydrogen in the nucleus of Halley's comet turned out to be much greater than their amount in the earth's water.
If we talk about how much this lump of dirt and snow has enough material for life, then here you can consider Halley's comet from different angles. Scientists' calculations, based on data on 46 comet appearances, speak in favor of the fact that the life of a celestial body is chaotic and constantly changing depending on external conditions. In other words, throughout its existence, the comet is in a state of dynamic chaos.
Presumably, the duration of the existence of Halley's comet is estimated at 7-10 billion years. Calculating the amount of matter lost during the last visit to our near-Earth space, scientists concluded that the comet's nucleus has already lost up to 80% of its original mass. It can be assumed that now our guest is at an advanced age and in a few millennia will fall apart into small fragments. The finale of this brightest life can happen within the solar system, in front of us, or, conversely, take place in the backyards of our common home.
Finally
The last visit of Halley's comet, which took place in 1986 and was expected for so many years, was the greatest disappointment for many. The main reason for the massive disappointment was the inability to observe a celestial body in the northern hemisphere. All preparations for the upcoming event went down the drain. On top of that, the period of observation of the comet turned out to be very short. This has led to the fact that few observations have been made by scientists around the world. A few days later, the comet disappeared behind the solar disk. The next meeting with the space guest has been postponed for 76 years.
Everything is more than serious.
Just a couple of days ago, information appeared in the media about the theory of the next apocalypse. This time, scientists associate it with the collision of the Earth and a comet. This could not but excite the minds of not only the public, but also the world's scientific community. What is this object? How far is it from the earth? How serious is this? Our editors have found answers to these questions.
So, according to scientists, this object is of the correct shape, which resembles a planet, but it does not move in orbit and this looks like an asteroid. In appearance, it is similar to Mars. Behind him stretches a train of triangular stones that burn, visually it resembles a fiery chain tied to the planet. Experts suggest that the plume was formed as a result of a sharp deceleration or, conversely, a rapid rotation of the planet's speed. In a telescope, the plume resembles the Latin letter "V". According to all the collected characteristics, the space object can be classified as a giant comet.
It is noteworthy that today scientists do not exclude the possibility of a collision of an asteroid and the Earth. And this poses a real threat to all mankind. According to preliminary estimates of astrophysicists, there will be a possible collision of two objects in 100-200 years.
Now scientists have begun to actively study the nature of this cosmic body, however, due to the fact that it flies at great speed, it is very difficult to obtain additional data. To date, NASA experts do not give official comments on this matter.
Having learned about the real threat to all life on our planet, most will ask themselves a completely logical question: how serious is it? Quite seriously, even very. Given the size and speed of the comet, this could be disastrous for the Earth. However, let's take a critical look at this issue, and you will see that not everything is so bad.
According to the data of world scientific communities in the field of astrophysics, last year alone, 97 unknown space objects flew near our planet, which, one way or another, posed a threat to all life on Earth. Of these, 28 were near-Earth, 64 were in the main asteroid belt, and 5 were comets. Only 10 of all the above cosmic bodies could actually collide with the Earth. They had a different degree of threat, which in turn was classified according to the size and speed of movement of celestial bodies. Just 6 days ago (June 4, to be exact), Johnson's Comet flew near the Earth, and astrophysicists watched its movement with bated breath. It resembled Neptune in size and speed.
According to experts, the real threat to all life on Earth is borne by celestial bodies that will fly near our planet in 2022, 2025, 2032, 2039. They can all collide with the Earth. Not a single astrophysicist in the world can guarantee that they will not pose a threat. Why? Yes, because any space object has its own nature: structure, speed, external factors and habitat, which at any second can change its movement or even destroy it. The chance of a collision is 50/50.
Can any of the above objects cause an apocalypse on Earth? Yes, but let's consider a couple more facts. Modern technologies do not stand still, by the time of the onset of a real threat to humanity, they will reach a qualitatively new level. Already now in the media every now and then there is information that humanity is colonizing Mars. Recently, world publications published information that a group of scientists intends to go to the Red Planet, where they will live for 900 days. To date, experts have found water on the Red Planet, possible remains of living organisms (which confirms the possibility of settling the planet) and similar characteristics with the Earth. However, there are skeptics who argue that the radiation background of Mars will not allow humanity to live on it. Such processes can be the cause of the occurrence of cancerous tumors in representatives of human civilization. It is natural that in 100-200 years we will either colonize this planet or find an alternative to it. Thus, at the disposal of mankind there is time, technology and an alternative planet for colonization.
Should we be afraid of a collision between the Earth and a giant comet? Yes, it's real. However, firstly, let's wait for the official comments of scientists, and secondly, we will give the opportunity to conduct a full-scale study of this issue, and only then we will draw conclusions. And today it remains for us to take into account the conclusion of world scientists, and draw our own conclusions. Our editors follow the latest developments in this area.
