Comets are one of the most mysterious celestial bodies that appear in the sky every now and then. Today, scientists believe that comets are a byproduct left over from the formation of stars and planets billions of years ago. They consist of a core of various types of ice (frozen water, carbon dioxide, ammonia and methane mixed with dust) and a large cloud of gas and dust surrounding the core, often called a "coma". Today, more than 5260 of them are known. The brightest and most impressive are collected here.
Great Comet of 1680
Discovered by German astronomer Gottfried Kirch on November 14, 1680, this magnificent comet became one of the brightest comets of the seventeenth century. She was remembered for being visible even in the daytime, as well as for her spectacular long tail.
Mrkos (1957)
Comet Mrkos was photographed by Alan McClure on August 13, 1957. The photo made a great impression on astronomers, since for the first time a double tail was noticed on a comet: a straight ion tail and a curved dust tail (both tails are directed in the opposite direction from the Sun).
De Kock-Paraskevopoulos (1941)
This strange but beautiful comet is best remembered for its long but faint tail, and for being visible at dawn and dusk. The comet received such a strange name because it was discovered simultaneously by an amateur astronomer named De Kock and Greek astronomer John S. Paraskevopoulos.
Skjellerup - Maristani (1927)
Comet Skjellerup-Maristany was a long-period comet whose brightness suddenly increased greatly in 1927. It was visible to the naked eye for approximately thirty-two days.
Mellish (1917)
Mellish is a periodic comet that has been observed primarily in the southern hemisphere. Many astronomers believe that Mellish will return to Earth's horizon in 2061.
Brooks (1911)
This bright comet was discovered in July 1911 by astronomer William Robert Brooks. It was remembered for its unusual blue color, which was the result of radiation from carbon monoxide ions.
Daniel (1907)
Comet Daniel was one of the most famous and widely observed comets of the early twentieth century.
Lovejoy (2011)
Comet Lovejoy is a periodic comet that comes extremely close to the sun at perihelion. It was discovered in November 2011 by Australian amateur astronomer Terry Lovejoy.
Bennett (1970)
The next comet was discovered by John Caister Bennett on December 28, 1969, when it was two astronomical units from the Sun. It was notable for its radiant tail, composed of plasma compressed into filaments by magnetic and electric fields.
Seki Lines (1962)
Initially visible only in the southern hemisphere, Seki Lines became one of the brightest objects in the night sky on April 1, 1962.
Arend-Roland (1956)
Visible only in the southern hemisphere during the first half of April 1956, Comet Arend-Roland was first discovered on November 8, 1956 by Belgian astronomers Sylvain Arend and Georges Roland in photographic images.
Eclipse (1948)
Eclipse is an exceptionally bright comet that was discovered during a solar eclipse on November 1, 1948.
Viscara (1901)
The great comet of 1901, sometimes called Comet Vizcar, became visible to the naked eye on April 12. It was visible as a second magnitude star with a short tail.
McNaught (2007)
Comet McNaught, also known as the Great Comet of 2007, is a periodic celestial body discovered on August 7, 2006 by British-Australian astronomer Robert McNaught. It was the brightest comet in forty years and was clearly visible to the naked eye in the southern hemisphere in January and February 2007.
Hyakutake (1996)
Comet Hyakutake was discovered on January 31, 1996, during its closest passage to Earth. It was named the "Great Comet of 1996" and is remembered for being the closest celestial body to Earth in the last two hundred years.
Vesta (1976)
Comet Vesta was perhaps the most exciting and eye-catching comet of the last century. It was visible to the naked eye, and its two huge tails stretched across the entire sky.
Ikeya-Seki (1965)
Also known as the "Great Comet of the Twentieth Century", Ikeya-Seki was the brightest comet of the last century, appearing even brighter than the Sun in daylight. According to Japanese observers, it was about ten times brighter than the full moon.
Halley's Comet (1910)
Despite the appearance of much brighter long-period comets, Halley is the brightest short-period (it returns to the Sun every 76 years) comet that is clearly visible to the naked eye.
Great Southern Comet (1947)
In December 1947, a huge comet was spotted near the setting sun, the brightest in decades (since Halley's Comet in 1910).
In 2009, Robert McNaught opened Comet C/2009 R1, which is approaching the Earth, and in mid-June 2010, residents of the northern hemisphere will be able to see it with the naked eye.
Comet Morehouse(C/1908 R1) is a comet discovered in the USA in 1908, which was the first of the comets to begin to be actively studied using photography. Surprising changes were noticed 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 the presence of 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 zero magnitude in brightness in March 1996 and produced a tail estimated to extend at least 7 degrees. Its apparent brightness is largely explained by its proximity to Earth - the comet passed from it at a distance of less than 15 million km. Its closest approach to the Sun is 0.23 AU, and its diameter is about 5 km.
Comet Humason(C/1961 R1) is a giant comet discovered in 1961. Its tails, despite being so far from the Sun, still extend 5 AU in length, 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, becoming the brightest comet in 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 tail length was 35 degrees.
Comets are one of the most mysterious celestial bodies that appear in the sky every now and then. Today, scientists believe that comets are a byproduct left over from the formation of stars and planets billions of years ago. They consist of a core of various types of ice (frozen water, carbon dioxide, ammonia and methane mixed with dust) and a large cloud of gas and dust surrounding the core, often called a "coma". Today, more than 5260 are known. Our review contains the brightest and most impressive.
1. Great comet of 1680
Discovered by German astronomer Gottfried Kirch on November 14, 1680, this magnificent comet became one of the brightest comets of the seventeenth century. She was remembered for being visible even in the daytime, as well as for her spectacular long tail.
2. Mrkos (1957)
Comet Mrkos was photographed by Alan McClure on August 13, 1957. The photo made a great impression on astronomers, since for the first time a double tail was noticed on a comet: a straight ion tail and a curved dust tail (both tails are directed in the opposite direction from the Sun).
3. De Kock-Paraskevopoulos (1941)
This strange but beautiful comet is best remembered for its long but faint tail, and for being visible at dawn and dusk. The comet received such a strange name because it was discovered simultaneously by an amateur astronomer named De Kock and Greek astronomer John S. Paraskevopoulos.
4. Skjellerup - Maristani (1927)
Comet Skjellerup-Maristany was a long-period comet whose brightness suddenly increased greatly in 1927. It was visible to the naked eye for approximately thirty-two days.
5. Mellish (1917)
Mellish is a periodic comet that has been observed primarily in the southern hemisphere. Many astronomers believe that Mellish will return to Earth's horizon in 2061.
6. Brooks (1911)
This bright comet was discovered in July 1911 by astronomer William Robert Brooks. It was remembered for its unusual blue color, which was the result of radiation from carbon monoxide ions.
7. Daniel (1907)
Comet Daniel was one of the most famous and widely observed comets of the early twentieth century.
8. Lovejoy (2011)
Comet Lovejoy is a periodic comet that comes extremely close to the sun at perihelion. It was discovered in November 2011 by Australian amateur astronomer Terry Lovejoy.
9. Bennett (1970)
The next comet was discovered by John Caister Bennett on December 28, 1969, when it was two astronomical units from the Sun. It was notable for its radiant tail, composed of plasma compressed into filaments by magnetic and electric fields.
10. Seki Lines (1962)
Initially visible only in the southern hemisphere, Seki Lines became one of the brightest objects in the night sky on April 1, 1962.
11. Arend-Roland (1956)
Visible only in the southern hemisphere during the first half of April 1956, Comet Arend-Roland was first discovered on November 8, 1956 by Belgian astronomers Sylvain Arend and Georges Roland in photographic images.
12. Eclipse (1948)
Eclipse is an exceptionally bright comet that was discovered during a solar eclipse on November 1, 1948.
13. Viscara (1901)
The great comet of 1901, sometimes called Comet Vizcar, became visible to the naked eye on April 12. It was visible as a second magnitude star with a short tail.
14. McNaught (2007)
Comet McNaught, also known as the Great Comet of 2007, is a periodic celestial body discovered on August 7, 2006 by British-Australian astronomer Robert McNaught. It was the brightest comet in forty years and was clearly visible to the naked eye in the southern hemisphere in January and February 2007.
15. Hyakutake (1996)
Comet Hyakutake was discovered on January 31, 1996, during its closest passage to Earth. It was named the "Great Comet of 1996" and is remembered for being the closest celestial body to Earth in the last two hundred years.
16. Vesta (1976)
Comet Vesta was perhaps the most exciting and eye-catching comet of the last century. It was visible to the naked eye, and its two huge tails stretched across the entire sky.
17. Ikeya-Seki (1965)
Also known as the "Great Comet of the Twentieth Century", Ikeya-Seki was the brightest comet of the last century, appearing even brighter than the Sun in daylight. According to Japanese observers, it was about ten times brighter than the full moon.
18. Halley's Comet (1910)
Despite the appearance of much brighter long-period comets, Halley is the brightest short-period (it returns to the Sun every 76 years) comet that is clearly visible to the naked eye.
19. Great Southern Comet (1947)
In December 1947, a huge comet was spotted near the setting sun, the brightest in decades (since Halley's Comet in 1910).
20. Great January comet (1910)
This comet was visible during January 17, 1910, as a snow-white object with a long and wide tail.
21. Great comet of 1577
Comet Hale-Bopp was perhaps the most widely observed comet of the twentieth century, as well as one of the brightest in modern history. It was visible to the naked eye for a record year and a half, twice as long as the previous record holder, the Great Comet of 1811.
24. Great September comet (1882)
It was a comet that became so bright in September 1882 that it could be seen close to the sun at perihelion.
25. Kohoutek (1973)
And the last comet on the list was first discovered on March 7, 1973 by Czech astronomer Lubos Kohoutek. It reached its perihelion on December 28, 1973, and its previous appearance is believed by astronomers to have been about 150,000 years ago. Comet Kohoutek will next return in about 75,000 years.
Especially for those interested in astronomy and science.
The fear of a comet colliding with the Earth will always live in the hearts of our scientists. And while they are afraid, let's remember the most sensational comets that have ever excited humanity.
Comet Lovejoy
In November 2011, Australian astronomer Terry Lovejoy discovered one of the largest comets of the circumsolar Kreutz group, with a diameter of about 500 meters. It flew through the solar corona and did not burn up, was clearly visible from Earth and was even photographed from the International Space Station.
Source: space.com
Comet McNaught
The first brightest comet of the 21st century, also called the "Great Comet of 2007". Discovered by astronomer Robert McNaught in 2006. In January and February 2007 it was clearly visible to the naked eye to residents of the planet's southern hemisphere. The comet's next return is not coming soon - in 92,600 years.
Source: wyera.com
Comets Hale-Bopp and Hyakutake
They appeared one after another - in 1996 and 1997, competing in brightness. If comet Hale-Bopp was discovered back in 1995 and flew strictly “on schedule,” Hyakutake was discovered only a couple of months before its approach to the Earth.
Source: website
Comet Lexel
In 1770, comet D/1770 L1, discovered by Russian astronomer Andrei Ivanovich Leksel, passed at a record close distance from Earth - only 1.4 million kilometers. This is about four times farther than the Moon is from us. The comet was visible to the naked eye.
Source: solarviews.com
1948 Eclipse Comet
On November 1, 1948, during a total solar eclipse, astronomers unexpectedly discovered a bright comet not far from the Sun. Officially named C/1948 V1, it was the last “sudden” comet of our time. It could be seen with the naked eye until the end of the year.
Source: philos.lv
Great January Comet of 1910
It appeared in the sky a couple of months before Halley's comet, which everyone was waiting for. The new comet was first noticed by miners from the diamond mines of Africa on January 12, 1910. Like many super-bright comets, it was visible even during the day.
Source: arzamas.academy
Great March Comet of 1843
Also included in the Kreutz family of circumsolar comets. It flew only 830 thousand kilometers from the center of the Sun and was clearly visible from Earth. Its tail is one of the longest of all known comets = two astronomical units (1 astronomical unit equals the distance between the Earth and the Sun).
Comets interest many people. These celestial bodies captivate young and older people, women and men, professional astronomers and simply amateur astronomers. And our portal website offers the latest news about the latest discoveries, photos and videos of comets, as well as much other useful information, which you can find in this section.
Comets are small celestial bodies revolving around the Sun along a conical section with a rather extended orbit, having a hazy appearance. As a comet approaches the Sun, it forms a coma and sometimes a tail of dust and gas.
Scientists suggest that comets periodically fly into the solar system from the Oort cloud, since it contains many cometary nuclei. As a rule, bodies located on the outskirts of the solar system consist of volatile substances (methane, water and other gases), which evaporate as they approach the Sun.
To date, more than four hundred short-period comets have been identified. Moreover, half of them were in more than one perihelion passage. Most of them belong to families. For example, many short-period comets (they orbit the Sun every 3-10 years) form the Jupiter family. The families of Uranus, Saturn and Neptune are small in number (Halley's famous comet belongs to the latter).
Comets that come from the depths of Space are nebulous objects with a tail trailing behind them. It often reaches several million kilometers in length. As for the comet's nucleus, it is a body of solid particles shrouded in a coma (foggy shell). A core with a diameter of 2 km can have a coma 80,000 km across. The sun's rays dislodge gas particles from the coma and throw them back, pulling them into a smoky tail moving behind her in outer space.
The brightness of comets largely depends on their distance from the Sun. Of all the comets, only a small part approaches the Earth and the Sun so much that they can be seen with the naked eye. Moreover, the most noticeable of them are usually called “great (large) comets.”
Most of the “shooting stars” (meteorites) we observe are of cometary origin. These are particles lost by a comet, which burn up when they enter the atmosphere of a planet.
Nomenclature of comets
Over the years of studying comets, the rules for naming them have been clarified and changed many times. Until the early 20th century, many comets were simply named by the year they were discovered, often with additional clarification regarding the season of the year or brightness if there were several comets in that year. For example, “Great September Comet of 1882”, “Great January Comet of 1910”, “Day Comet of 1910”.
After Halley was able to prove that comets 1531, 1607 and 1682 were the same comet, it was named Halley's Comet. He also predicted that in 1759 she would return. The second and third comets were named Bela and Encke in honor of the scientists who calculated the orbit of the comets, despite the fact that the first comet was observed by Messier, and the second by Mechain. A short time later, periodic comets were named after their discoverers. Well, those comets that were observed only during one perihelion passage were named, as before, by the year of appearance.
At the beginning of the twentieth century, when comets began to be discovered more often, a decision was made on the final naming of comets, which has been preserved to this day. Only when the comet was identified by three independent observers did it receive a name. Many comets have been discovered in recent years through instruments discovered by entire teams of scientists. Comets in such cases are named after their instruments. For example, comet C/1983 H1 (IRAS - Araki - Alcock) was discovered by the IRAS satellite, George Alcock and Genichi Araki. In the past, another team of astronomers discovered periodic comets, to which a number was added, for example, comets Shoemaker-Levy 1 - 9. Today, a huge number of planets are discovered by a variety of instruments, which made this system impractical. Therefore, it was decided to resort to a special system for naming comets.
Until early 1994, comets were given temporary designations that consisted of the year of discovery plus a Latin lowercase letter indicating the order in which they were discovered in that year (for example, comet 1969i was the 9th comet to be discovered in 1969). Once the comet passed perihelion, its orbit was established and it received a permanent designation, namely the year of perihelion passage plus a Roman numeral, which indicates the order of perihelion passage in that year. For example, comet 1969i was given the permanent designation 1970 II (meaning it was the second comet to pass perihelion in 1970).
As the number of discovered comets increased, this procedure became very inconvenient. Therefore, the International Astronomical Union adopted a new system for naming comets in 1994. Today, the name of comets includes the year of discovery, the letter indicating the half of the month in which the discovery took place, and the number of the discovery itself in that half of the month. This system is similar to the one used to name asteroids. Thus, the fourth comet, which was discovered in 2006, in the second half of February is designated 2006 D4. A prefix is also placed before the designation. He explains the nature of the comet. It is customary to use the following prefixes:
· C/ is a long-period comet.
· P/ - short-period comet (one that was observed at two or more perihelion passages, or a comet whose period is less than two hundred years).
· X/ - a comet for which it was not possible to calculate a reliable orbit (most often for historical comets).
· A/ - objects mistakenly taken for comets, but turned out to be asteroids.
· D/ - comets were lost or destroyed.
The structure of comets
Gas components of comets
Core
The nucleus is the solid part of the comet where almost all of its mass is concentrated. At the moment, the nuclei of comets are not available for study, since they are hidden by the constantly forming luminous matter.
The core, according to the most common Whipple model, is a mixture of ice with the inclusion of particles of meteoric matter. The layer of frozen gases, according to this theory, alternates with dust layers. As the gases heat up, they evaporate and carry clouds of dust with them. Thus, the formation of dust and gas tails in comets can be explained.
But according to the results of studies carried out using an American automatic station in 2015, the core is made up of loose material. This is a lump of dust with pores that occupy up to 80 percent of its volume.
Coma
Coma is a light, foggy shell surrounding the core, consisting of dust and gases. Most often it stretches from 100 thousand to 1.4 million km from the core. Under high light pressure it becomes deformed. As a result, it is elongated in the antisolar direction. Together with the nucleus, the coma forms the head of the comet. Typically a coma consists of 4 main parts:
- internal (chemical, molecular and photochemical) coma;
- visible coma (or also called radical coma);
- atomic (ultraviolet) coma.
Tail
As they approach the Sun, bright comets form a tail - a faint luminous stripe, which most often, as a result of the action of sunlight, is directed away from the Sun in the opposite direction. Despite the fact that the coma and tail contain less than one millionth of the comet's mass, almost 99.9% of the glow that we see as the comet passes through the sky consists of gas formations. This is because the core has a low albedo and is itself very compact.
The tails of comets can differ in both shape and length. For some, they stretch across the entire sky. For example, the tail of the comet, which was seen in 1944, had a length of 20 million km. Even more impressive is the length of the tail of the Great Comet of 1680, which was 240 million km. There have also been cases where the tail is separated from the comet.
The tails of comets are almost transparent and do not have sharp outlines - stars are clearly visible through them, since they are formed from super-rarefied matter (its density is much less than the density of gas from a lighter). As for the composition, it is varied: tiny particles of dust or gas, or a mixture of both. The composition of most dust grains resembles asteroid materials, as revealed by the Stardust spacecraft's study of comet 81P/Wilda. We can say that this is “visible nothing”: we can see the tails of comets only because the dust and gas glow. Moreover, the combination of gas is directly related to its ionization by UV rays and streams of particles that are ejected from the solar surface, and dust scatters sunlight.
At the end of the 19th century, astronomer Fyodor Bredikhin developed the theory of shapes and tails. He also created a classification of comet tails, which is still used in astronomy today. He proposed classifying comet tails into three main types: narrow and straight, directed away from the Sun; curved and wide, deviating from the central luminary; short, strongly inclined from the Sun.
Astronomers explain such different shapes of comet tails as follows. The constituent particles of comets have different properties and composition and react differently to solar radiation. Therefore, the paths of these particles in space “diverge,” as a result of which the tails of space travelers take on different shapes.
Study of comets
Humanity has shown interest in comets since ancient times. Their unexpected appearance and unusual appearance have served as a source of various superstitions for many centuries. The ancients associated the appearance in the sky of these cosmic bodies with a brightly glowing tail with the onset of difficult times and impending troubles.
Thanks to Tycho Brahe, during the Renaissance, comets began to be classified as celestial bodies.
People gained a more detailed understanding of comets thanks to the 1986 trip to Halley's comet on spacecraft such as Giotto, as well as Vega-1 and Vega-2. Instruments installed on these devices transmitted images of the comet's nucleus and various information about its shell to Earth. It turned out that the comet's nucleus is composed mainly of simple ice (with minor inclusions of methane and carbon dioxide ice) and field particles. Actually, they form the shell of the comet, and as it approaches the Sun, some of them, under the influence of pressure from the solar wind and solar rays, turn into the tail.
According to scientists, the dimensions of the nucleus of Halley's comet are several kilometers: 7.5 km in the transverse direction, 14 km in length.
The nucleus of Halley's comet is irregular in shape and constantly rotates around an axis, which, according to Friedrich Bessel's assumptions, is almost perpendicular to the plane of the comet's orbit. As for the rotation period, it was 53 hours, which agreed well with the calculations.
NASA's Deep Impact spacecraft dropped a probe on Comet Tempel 1 in 2005, allowing it to image its surface.
Study of comets in Russia
The first information about comets appeared in the Tale of Bygone Years. It was clear that the chroniclers attached special importance to the appearance of comets, since they were considered harbingers of various misfortunes - pestilence, wars, etc. But in the language of Ancient Rus' they were not given any separate name, since they were considered tailed stars moving across the sky. When the description of the comet appeared on the pages of the chronicles (1066), the astronomical object was called “a great star; star image of a copy; star... emitting rays, which is also called the sparkler.”
The concept of “comet” appeared in Russian after the translation of European works that dealt with comets. The earliest mention was seen in the collection “Golden Beads,” which is something like an entire encyclopedia about the world order. At the beginning of the 16th century, "Lucidarius" was translated from German. Since the word was new for Russian readers, the translator explained it with the familiar name “star”, namely “the star of the comita gives shine from itself like a ray.” But the concept of “comet” entered the Russian language only in the mid-1660s, when comets actually appeared in the European sky. This event aroused particular interest. From translated works, the Russians learned that comets are not much like stars. Until the beginning of the 18th century, the attitude towards the appearance of comets as signs was preserved both in Europe and in Russia. But then the first works appeared that denied the mysterious nature of comets.
Russian scientists mastered European scientific knowledge about comets, which allowed them to make a significant contribution to their study. Astronomer Fyodor Bredinich in the second half of the 19th century built a theory of the nature of comets, explaining the origin of tails and their bizarre variety of shapes.
For all those who want to get acquainted with comets in more detail and learn about current news, our portal website invites you to follow the materials in this section.