Orbits of solar system comets. Comet orbits

Comets– small celestial bodies revolving around the Sun: description and characteristics with photos, 10 interesting facts about comets, list of objects, names.

In the past, people viewed the arrival of comets with horror and fear, as they believed that it was an omen of death, disaster or divine punishment. Chinese scientists have been collecting data for centuries, tracking the frequency of object arrivals and their trajectories. These records have become valuable resources for modern astronomers.

Today we know that comets are leftover material and small bodies from the formation of the Solar System 4.6 billion years ago. They are represented by ice on which there is a dark crust of organic material. This is why they got the nickname "dirty snowballs". These are valuable objects for studying the early system. They could also become a source of water and organic compounds - essential life components.

In 1951, Gerard Kuiper proposed that beyond Neptune's orbital path lies a disk-shaped belt containing a population of dark comets. These icy objects are periodically pushed into orbit and become short-period comets. They spend less than 200 years in orbit. It is more difficult to observe comets with long periods, whose orbital paths last more than two centuries. Such objects live in the territory of the Oort cloud (at a distance of 100,000 AU). One flyby can take up to 30 million years.

Each comet has a frozen part - the nucleus, which does not exceed several kilometers in length. Consists of ice fragments, frozen gases and dust particles. As the comet approaches the Sun, it heats up and forms a coma. Heating causes the ice to sublimate into gas, causing the coma to expand. Sometimes it can cover hundreds of thousands of km. Solar wind and pressure can eliminate dust and coma gas, resulting in a long and bright tail. Usually there are two of them - dust and gas. Below is a list of the most famous comets in the Solar System. Follow the link to study the description, characteristics and photos of small bodies.

Most comets move at a safe distance from the Sun (Halley's comet does not come closer than 89 million km). But some crash directly into a star or get so close that they evaporate.

Name of comets

The name of a comet can be tricky. Most often they are named after the discoverers - a person or a spaceship. This rule appeared only in the 20th century. For example, Comet Shoemaker-Levy 9 is named after Eugene and Carolyn Shoemaker and David Levy. Be sure to read interesting facts about comets and information you need to know.

Comets: 10 Things You Need to Know About

• If our star the Sun were the size of a door, then the Earth would resemble a coin, dwarf Pluto would be the head of a pin, and the largest Kuiper Belt comet (100 km wide) would be the diameter of a speck of dust;
• Short-period comets (spending less than 200 years per orbital flight) live in the icy territory of the Kuiper belt beyond the orbit of Neptune (30-55 AU). At its maximum distance, Comet Halley is located 5.3 billion km from the Sun. Long-period comets (long or unpredictable orbits) approach from the Oort cloud (100 AU from the Sun);
• One day on Comet Halley lasts 2.2-7.4 days (one axial rotation). It takes 76 years to complete one revolution around the Sun;
• Comets are cosmic snowballs of frozen gases, dust and rocks;
• As the comet approaches the Sun, it heats up, creating an atmosphere (coma) capable of covering hundreds of thousands of kilometers in diameter;
• Comets do not have rings;
• Comets have no satellites;
• Several missions were sent to comets, and Stardust-NExT and Deep Impact EPOXI managed to obtain samples;
• Comets are not capable of supporting life, but they are believed to be the source of it. In their composition they can transport water and organic compounds that may have ended up on Earth during a collision;
• Halley's Comet is depicted in the Bayeux Tapestry of 1066, which recounts the fall of King Harold at the hands of William the Conqueror;

Comets are cosmic snowballs made of frozen gases, rocks and dust and are roughly the size of a small city. When a comet's orbit brings it close to the Sun, it heats up and spews out dust and gas, causing it to become brighter than most planets. Dust and gas form a tail that stretches from the Sun for millions of kilometers.

10 facts you need to know about comets

1. If the Sun were as big as a front door, the Earth would be the size of a dime, the dwarf planet Pluto would be the size of a pinhead, and the largest comet of the Kuiper Belt (which is about 100 km across, which is about one twentieth of Pluto ) will be the size of a speck of dust.
2. Short-period comets (comets that orbit the Sun in less than 200 years) live in an icy region known as the Kuiper Belt, located beyond the orbit of Neptune. Long comets (comets with long, unpredictable orbits) originate in the far reaches of the Oort Cloud, which is located at distances of up to 100 thousand AU.
3. Days on the comet change. For example, a day on Halley's Comet ranges from 2.2 to 7.4 Earth days (the time required for the comet to complete a revolution on its axis). Halley's Comet makes a complete revolution around the Sun (a year on the comet) in 76 Earth years.
4. Comets are cosmic snowballs consisting of frozen gases, rocks and dust.
5. The comet heats up as it approaches the Sun and creates an atmosphere or com. The lump can be hundreds of thousands of kilometers in diameter.
6. Comets do not have satellites.
7. Comets do not have rings.
8. More than 20 missions were aimed at studying comets.
9. Comets cannot support life, but may have brought water and organic compounds - the building blocks of life - through collisions with Earth and other objects in our solar system.
10. Halley's Comet was first mentioned in Bayeux from 1066, which recounts the overthrow of King Harold by William the Conqueror at the Battle of Hastings.

Comets: The Dirty Snowballs of the Solar System

Comets On our journeys through the solar system, we may be lucky enough to encounter giant balls of ice. These are comets of the solar system. Some astronomers call comets "dirty snowballs" or "icy mud balls" because they are made mostly of ice, dust and rock debris. Ice can consist of either ice water or frozen gases. Astronomers believe that comets may be composed of primordial material that formed the basis for the formation of the solar system.

Although most of the small objects in our solar system are very recent discoveries, comets have been well known since ancient times. The Chinese have records of comets that date back to 260 BC. This is because comets are the only small bodies in the solar system that can be seen with the naked eye. Comets that orbit the Sun are quite a spectacular sight.

Comet tail

Comets are actually invisible until they begin to approach the Sun. At this moment they begin to heat up and an amazing transformation begins. Dust and gases frozen in the comet begin to expand and escape with explosive speed.

The solid part of a comet is called the comet's nucleus, while the cloud of dust and gas around it is known as the comet's coma. Solar winds pick up material in the coma, leaving a tail behind the comet that extends several million miles. As the sun illuminates, this material begins to glow. Eventually the comet's famous tail forms. Comets and their tails can often be seen from Earth with the naked eye.

The Hubble Space Telescope captured Comet Shoemaker-Levy 9 as it struck the surface of Jupiter.

Some comets can have up to three separate tails. One of them will consist mainly of hydrogen, and is invisible to the eye. The other tail of dust will glow bright white, and the third tail of plasma will usually have a blue glow. When the Earth passes through these dust trails left by comets, the dust enters the atmosphere and creates meteor showers.

Active jets on Comet Hartley 2

Some comets fly in an orbit around the Sun. They are known as periodic comets. A periodic comet loses a significant portion of its material each time it passes near the Sun. Eventually, after all this material is lost, they will cease to be active and wander around the solar system like a dark rocky ball of dust. Halley's Comet is probably the most famous example of a periodic comet. The comet changes its appearance every 76 years.

History of comets
The sudden appearance of these mysterious objects in ancient times was often seen as a bad omen and a warning of natural disasters in the future. We currently know that most comets reside in a dense cloud located at the edge of our solar system. Astronomers call it the Oort Cloud. They believe that gravity from the stray passage of stars or other objects could knock some of the Oort Cloud comets off and send them on a journey into the inner solar system.

Manuscript depicting comets among the ancient Chinese

Comets can also collide with the Earth. In June 1908, something exploded high in the atmosphere above the village of Tunguska in Siberia. The explosion had the force of 1,000 bombs dropped on Hiroshima and leveled trees for hundreds of miles. The absence of any meteorite fragments led scientists to believe that it may have been a small comet that exploded upon impact with the atmosphere.

Comets may also have been responsible for the extinction of the dinosaurs, and many astronomers believe that ancient comet impacts brought much of the water to our planet. While there is a possibility that the Earth could be hit by a large comet again in the future, the chances of this event happening in our lifetime are better than one in a million.

For now, comets simply continue to be objects of wonder in the night sky.

The most famous comets

Comet ISON

Comet ISON was the subject of the most coordinated observations in the history of comet studies. Over the course of a year, more than a dozen spacecraft and numerous ground-based observers collected what is believed to be the largest collection of data on a comet.

Known in the catalog as C/2012 S1, Comet ISON began its journey to the inner Solar System about three million years ago. It was first spotted in September 2012, at a distance of 585,000,000 miles. This was its very first trip around the Sun, that is, it was made of primordial matter that arose in the early days of the formation of the Solar System. Unlike comets that have already made multiple passes through the inner Solar System, the upper layers of Comet ISON have never been heated by the Sun. The comet represented a kind of time capsule, which captured the moment of the formation of our solar system.

Scientists from around the world launched an unprecedented observing campaign, using many ground-based observatories and 16 spacecraft (all but four successfully studied the comet).

On November 28, 2013, scientists observed Comet ISON being torn apart by the gravitational forces of the Sun.

Russian astronomers Vitaly Nevsky and Artem Novichonok discovered the comet using a 4-meter telescope in Kislovodsk, Russia.

ISON is named after the night sky survey program that discovered it. ISON is a group of observatories in ten countries that work together to detect, monitor and track objects in space. The network is managed by the Institute of Applied Mathematics of the Russian Academy of Sciences.

Comet Encke

Comet 2P/EnckeComet 2P/Encke is a small comet. Its core measures approximately 4.8 km (2.98 mi) in diameter, about one-third the size of the object thought to have killed off the dinosaurs.

The comet's orbital period around the Sun is 3.30 years. Comet Encke has the shortest orbital period of any known comet within our Solar System. Encke last passed perihelion (closest point to the Sun) in November 2013.

Photo of a comet taken by the Spitzer telescope

Comet Encke is the parent comet of the Taurids meteor shower. The Taurids, which peak in October/November each year, are fast meteors (104,607.36 km/h or 65,000 mph) known for their fireballs. Fireballs are meteors that are as bright or even brighter than the planet Venus (when viewed in the morning or evening sky with an apparent brightness value of -4). They can create large explosions of light and color and last longer than the average meteor shower. This is because fireballs come from larger particles of material from the comet. Often, this special stream of fireballs occurs on or around the day of Halloween, making them known as Halloween Fireballs.

Comet Encke approached the Sun in 2013 at the same time that Comet Ison was much talked about and presented, and because of this was photographed by both the MESSENGER and STEREO spacecraft.

Comet 2P/Encke was first discovered by Pierre F.A. Mechain on January 17, 1786. Other astronomers found this comet on subsequent passages, but these observations were not identified as the same comet until Johann Franz Encke calculated its orbit.

Comets are typically named after their discoverer(s) or the name of the observatory/telescope used in the discovery. However, this comet is not named after its discoverer. Instead, it was named after Johann Franz Encke, who calculated the comet's orbit. The letter P indicates that 2P/Encke is a periodic comet. Periodic comets have orbital periods of less than 200 years.

Comet D/1993 F2 (Shoemaker - Levy)

Comet Shoemaker-Levy 9 was captured by Jupiter's gravity, dispersed, and then crashed into the giant planet in July 1994.

When the comet was discovered in 1993, it was already fragmented into more than 20 fragments traveling around the planet in a two-year orbit. Further observations revealed that the comet (believed to have been a single comet at the time) made a close approach to Jupiter in July 1992 and was fragmented by tidal forces as a result of the planet's powerful gravity. The comet is believed to have orbited Jupiter for about ten years before its death.

A comet breaking into many pieces was rare, and seeing a comet captured in orbit near Jupiter was even more unusual, but the biggest and rarest discovery was that fragments crashed into Jupiter.

NASA had a spacecraft that observed - for the first time in history - a collision between two bodies in the solar system.

NASA's Galileo orbiter (then on its way to Jupiter) was able to establish a direct view of the parts of the comet, labeled A through W, that collided with Jupiter's clouds. The clashes began on July 16, 1994 and ended on July 22, 1994. Many ground-based observatories and orbiting spacecraft, including the Hubble Space Telescope, Ulysses and Voyager 2, have also studied the collisions and their consequences.

The trail of a comet on the surface of Jupiter

A “freight train” of fragments crashed on Jupiter with the force of 300 million atomic bombs. They created huge plumes of smoke that were 2,000 to 3,000 kilometers (1,200 to 1,900 miles) high, and heated the atmosphere to very hot temperatures of 30,000 to 40,000 degrees Celsius (53,000 to 71,000 degrees Fahrenheit). Comet Shoemaker-Levy 9 left dark, ring-shaped scars that were eventually worn away by Jupiter's winds.

When the clash happened in real time, it was more than just a show. This gave scientists a new look at Jupiter, Comet Shoemaker-Levy 9, and cosmic collisions in general. Researchers were able to deduce the composition and structure of the comet. The collision also left behind dust that is found at the top of Jupiter's clouds. By observing dust spreading across the planet, scientists were able to track the direction of high-altitude winds on Jupiter for the first time. And by comparing changes in the magnetosphere with changes in the atmosphere after the impact, scientists were able to study the relationship between the two.

Scientists estimate that the comet was originally about 1.5 - 2 kilometers (0.9 - 1.2 miles) wide. If an object of this size struck the Earth, it would have devastating consequences. The impact could send dust and debris into the sky, creating a fog that would cool the atmosphere and absorb sunlight, shrouding the entire planet in darkness. If the fog lasts long enough, plant life will die - along with the people and animals that depend on them to survive.

These types of collisions were more common in the early solar system. It is likely that comet collisions occurred mainly because Jupiter lacked hydrogen and helium.

Currently, collisions of this magnitude probably occur only once every few centuries - and pose a real threat.

Comet Shoemaker-Levy 9 was discovered by Caroline and Eugene Shoemaker and David Levy in an image taken on March 18, 1993, by the 0.4-meter Schmidt Telescope on Mount Palomar.

The comet was named after its discoverers. Comet Shoemaker-Levy 9 was the ninth short-period comet discovered by Eugene and Caroline Shoemaker and David Levy.

Comet Tempel

Comet 9P/TempelComet 9P/Tempel orbits the Sun in the asteroid belt located between the orbits of Mars and Jupiter. The comet last passed its perihelion (closest point to the Sun) in 2011 and will return again in 2016.

Comet 9P/Tempel belongs to the Jupiter family of comets. Jupiter-family comets are comets that have an orbital period of less than 20 years and orbit near a gas giant. Comet 9P/Tempel takes 5.56 years to complete one full period around the Sun. However, the comet's orbit gradually changes over time. When Comet Tempel was first discovered, its orbital period was 5.68 years.

Comet Tempel is a small comet. Its core is about 6 km (3.73 miles) in diameter, believed to be half the size of the object that killed off the dinosaurs.

Two missions were sent to study this comet: Deep Impact in 2005 and Stardust in 2011.

Possible impact track on the surface of Comet Tempel

Deep Impact fired an impactor onto the surface of a comet, becoming the first spacecraft capable of extracting material from the surface of a comet. The collision produced relatively little water and a lot of dust. This suggests that the comet is far from being a “block of ice.” The impact of the impact projectile was later captured by the Stardust spacecraft.

Comet 9P/Tempel was discovered by Ernst Wilhelm Leberecht Tempel (better known as Wilhelm Tempel) on April 3, 1867.

Comets are usually named after their discoverer or the observatory/telescope used in the discovery. Because Wilhelm Tempel discovered this comet, it is named after him. The letter "P" means that Comet 9P/Tempel is a short-period comet. Short-period comets have an orbital period of less than 200 years.

Comet Borelli

Comet 19P/Borelli Resembling a chicken leg, the small nucleus of Comet 19P/Borelli is about 4.8 km (2.98 miles) in diameter, about a third the size of the object that killed off the dinosaurs.

Comet Borelli orbits the Sun in the asteroid belt and is a member of the Jupiter family of comets. Jupiter-family comets are comets that have an orbital period of less than 20 years and orbit near a gas giant. It takes about 6.85 years to complete one full revolution around the Sun. The comet passed its last perihelion (closest point to the Sun) in 2008 and will return again in 2015.

The Deep Space 1 spacecraft flew close to Comet Borelli on September 22, 2001. Traveling at 16.5 km (10.25 miles) per second, Deep Space 1 passed 2,200 km (1,367 miles) above the nucleus of Comet Borelli. This spacecraft took the best photo of a comet's nucleus ever.

Comet 19P/Borrelli was discovered by Alphonse Louis Nicolas Borrelli on December 28, 1904 in Marseille, France.

Comets are usually named after their discoverer or the observatory/telescope used in the discovery. Alphonse Borrelli discovered this comet and that is why it is named after him. The "P" means that 19P/Borelli is a short-period comet. Short-period comets have an orbital period of less than 200 years.

Comet Hale-Bopp

Comet C/1995 O1 (Hale-Bopp) Also known as the Great Comet of 1997, Comet C/1995 O1 (Hale-Bopp) is a fairly large comet, with a nucleus measuring up to 60 km (37 miles) in diameter. This is about five times larger than the supposed object that killed the dinosaurs. Due to its large size, this comet was visible to the naked eye for 18 months in 1996 and 1997.

Comet Hale-Bopp takes about 2,534 years to complete one revolution around the Sun. The comet passed its last perihelion (closest point to the Sun) on April 1, 1997.

Comet C/1995 O1 (Hale-Bopp) was discovered in 1995 (July 23), independently by Alan Hale and Thomas Bopp. Comet Hale-Bopp was discovered at an astonishing distance of 7.15 AU. One AU is equal to approximately 150 million km (93 million miles).

Comets are usually named after their discoverer or the observatory/telescope used in the discovery. Because Alan Hale and Thomas Bopp discovered this comet, it is named after them. The letter "S" stands for. That Comet C/1995 O1 (Hale-Bopp) is a long-period comet.

Comet Wild

Comet 81P/Wilda81P/Wilda (Wild 2) is a small comet with a flattened ball shape and a size of about 1.65 x 2 x 2.75 km (1.03 x 1.24 x 1.71 mi). Its period of revolution around the Sun is 6.41 years. Comet Wild last passed perihelion (closest point to the Sun) in 2010 and will return again in 2016.

Comet Wild is known as a new periodic comet. The comet orbits the Sun between Mars and Jupiter, but it has not always traveled this orbital path. Initially, the orbit of this comet passed between Uranus and Jupiter. On September 10, 1974, gravitational interactions between this comet and the planet Jupiter changed the comet's orbit into a new shape. Paul Wild discovered this comet during its first revolution around the Sun in a new orbit.

Animated image of a comet

Since Wilda is a new comet (it didn't have as many close orbits around the Sun), it's an ideal specimen for discovering something new about the early Solar System.

NASA used this special comet when, in 2004, they assigned the Stardust mission to fly to it and collect coma particles—the first collection of this kind of extraterrestrial material beyond the orbit of the Moon. These samples were collected in an airgel collector as the craft flew 236 km (147 miles) from the comet. The samples were then returned to Earth in an Apollo-like capsule in 2006. In those samples, scientists discovered glycine: a fundamental building block of life.

Comets are typically named after their discoverer(s) or the name of the observatory/telescope used in the discovery. Because Paul Wild discovered this comet, it was named after him. The letter "P" means that 81P/Wilda (Wild 2) is a "periodic" comet. Periodic comets have orbital periods of less than 200 years.

Comet Churyumov-Gerasimenko

Comet 67P / Churyumova-Gerasimenko may go down in history as the first comet on which robots from Earth will land and who will accompany it throughout its orbit. The Rosetta spacecraft, which carries the Philae lander, plans to rendezvous with the comet in August 2014 to accompany it on its journey to and from the inner solar system. Rosetta is a mission of the European Space Agency (ESA), which is provided with essential instruments and support by NASA.

Comet Churyumov-Gerasimenko makes a loop around the Sun in an orbit intersecting the orbits of Jupiter and Mars, approaching but not entering Earth's orbit. Like most Jupiter-family comets, it is believed to have fallen from the Kuiper Belt, the region beyond Neptune's orbit, as a result of one or more collisions or gravitational tugs.

Close-up of the surface of comet 67P/Churyumov-Gerasimenko

Analysis of the comet's orbital evolution indicates that until the mid-19th century, the closest distance to the Sun was 4.0 AU. (about 373 million miles or 600 million kilometers), which is about two-thirds of the way from the orbit of Mars to Jupiter. Because the comet is too far from the heat of the Sun, it has not grown a ball (shell) or tail, so the comet is not visible from Earth.

But scientists estimate that in 1840, a fairly close encounter with Jupiter must have sent the comet flying deeper into the solar system, down to about 3.0 AU. (about 280 million miles or 450 million kilometers) from the Sun. The Churyumov-Gerasimenko perihelion (closest approach to the Sun) was slightly closer to the Sun for the next century, and then Jupiter gave the comet another gravitational shock in 1959. The comet's perihelion has since stopped at 1.3 AU, about 27 million miles (43 million kilometers) beyond Earth's orbit.

Dimensions of comet 67P/Churyumov-Gerasimenko

The comet's nucleus is considered to be quite porous, giving it a density much lower than that of water. When heated by the Sun, the comet is believed to emit about twice as much dust as gas. A small detail known about the comet's surface is that a landing site for Philae will not be selected until Rosetta surveys it at close range.

During recent visits to our part of the solar system, the comet was not bright enough to be seen from Earth without a telescope. This coming year we will be able to see the fireworks close up, thanks to the eyes of our robots.

Discovered on October 22, 1969 at the Alma-Ata Observatory, USSR. Klim Ivanovich Churyumov found an image of this comet while examining a photographic plate of another comet (32P/Comas Sola), taken by Svetlana Ivanova Gerasimenko on September 11, 1969.

67P indicates that it was the 67th periodic comet discovered. Churyumov and Gerasimenko are the names of the discoverers.

Comet Siding Spring

Comet McNaught Comet C/2013 A1 (Siding Spring) heads toward Mars on a low-level flight on October 19, 2014. The comet's nucleus is expected to zip past the planet within a cosmic hair, which is 84,000 miles (135,000 km), about one-third the distance from Earth to the Moon and one-tenth the distance that any known comet has passed Earth. This represents both an excellent opportunity for study and a potential hazard for spacecraft in this area.

Because the comet will approach Mars almost head-on, and because Mars is in its own orbit around the Sun, they will pass each other at a tremendous speed of about 35 miles (56 kilometers) per second. But the comet can be so large that Mars can fly through high-speed particles of dust and gas for several hours. The Martian atmosphere will likely protect rovers on the surface, but spacecraft in orbit will be bombarded by particles moving two or three times faster than the meteorites that spacecraft typically withstand.

NASA spacecraft transmits first photographs of Comet Siding Spring to Earth

“Our plans for using spacecraft on Mars to observe Comet McNaught will be coordinated with plans for how orbiters can stay out of the flow and be protected if necessary,” said Rich Zurek, chief scientist for the Mars program at NASA Jet Propulsion Laboratory.

One way to protect orbiters is to position them behind Mars during the riskiest surprise encounters. Another way is for the spacecraft to “dodge” the comet, trying to shield the most vulnerable equipment. But such maneuvers could cause changes in the orientation of solar panels or antennas in ways that interfere with the vehicles' ability to generate power and communicate with Earth. "These changes will require an enormous amount of testing," said Soren Madsen, chief engineer for the Mars exploration program at JPL. “There are a lot of preparations that need to be made now to prepare ourselves for the eventuality that we learn in May that the demonstration flight will be risky.”

Comet Siding Spring fell from the Oort Cloud, a huge spherical region of long-period comets that circles the Solar System. To get an idea of ​​how far away that is, consider this situation: Voyager 1, which has been traveling in space since 1977, is much further away than any of the planets, and has even emerged from the heliosphere, a huge bubble of magnetism and ionized gas. radiating from the Sun. But it will take the ship another 300 years to reach the inner "edge" of the Oort Cloud, and at its current speed of a million miles a day it will take about 30,000 more years to finish passing through the cloud.

Every once in a while, some gravitational pull - perhaps from passing a star - will push the comet to break free from its impossibly vast and distant vault, and it will fall into the Sun. This is what should have happened to Comet McNaught several million years ago. All this time the fall was directed towards the inner part of the solar system, and it gives us only one chance to study it. According to available estimates, her next visit will be in about 740 thousand years.

"C" indicates that the comet is not periodic. 2013 A1 shows that it was the first comet discovered in the first half of January 2013. Siding Spring is the name of the observatory where it was discovered.

Comet Giacobini-Zinner

Comet 21P/Giacobini-Zinner is a small comet with a diameter of 2 km (1.24 mi). The period of revolution around the Sun is 6.6 years. The last time Comet Giacobini-Zinner passed perihelion (closest point to the Sun) was on February 11, 2012. The next perihelion passage will be in 2018.

Every time Comet Giacobini-Zinner returns to the inner Solar System, its core sprays ice and rocks into space. This shower of debris leads to the annual meteor shower: the Draconids, which occurs every year in early October. The Draconids radiate from the northern constellation Draco. For many years the shower is weak and very few meteorites are visible during this period. However, there are occasional references in the records to Draconid (sometimes called Jacobinid) meteor storms. A meteor storm occurs when a thousand or more meteors are visible within an hour at the observer's location. At its peak in 1933, 500 Draconid meteors were seen within a minute in Europe. 1946 was also a good year for the Draconids, with about 50-100 meteors being spotted in one minute in the US.

Coma and nucleus of comet 21P/Giacobini-Zinner

In 1985 (September 11), a re-designated mission called ICE (International Comet Explorer, formally International Sun-Earth Explorer-3) was assigned to collect data from this comet. ICE was the first spacecraft to follow a comet. ICE later joined the famous "armada" of spacecraft sent to Halley's Comet in 1986. Another mission, called Sakigaki, from Japan, was scheduled to follow the comet in 1998. Unfortunately, the spacecraft did not have enough fuel to reach the comet.

Comet Giacobini-Zinner was discovered on December 20, 1900 by Michel Giacobini at the Nice Observatory in France. Information about this comet was later restored by Ernst Zinner in 1913 (October 23).

Comets are typically named after their discoverer(s) or the name of the observatory/telescope used in the discovery. Since Michel Giacobini and Ernst Zinner discovered and recovered this comet, it is named after them. The letter "P" means that Comet Giacobini-Zinner is a "periodic" comet. Periodic comets have orbital periods of less than 200 years.

Comet Thatcher

Comet C/1861 G1 (Thatcher)Comet C/1861 G1 (Thatcher) takes 415.5 years to complete one revolution around the Sun. Comet Thatcher passed its final perihelion (closest point to the Sun) in 1861. Comet Thatcher is a long-period comet. Long-period comets have orbital periods of more than 200 years.

When comets pass around the Sun, the dust they emit spreads into a dust trail. Every year, when Earth passes through this comet trail, space debris collides with our atmosphere, where it breaks up and creates fiery, colorful streaks in the sky.

Chunks of space debris coming from Comet Thatcher and interacting with our atmosphere create the Lyrid meteor shower. This annual meteor shower occurs every April. The Lyrids are among the oldest known meteor showers. The first documented Lyrid meteor shower dates back to 687 BC.

Comets are usually named after their discoverer or the observatory/telescope used in the discovery. Since A.E. Thatcher discovered this comet, it is named after him. The "C" means that Comet Thatcher is a long-period comet, meaning its orbital period is more than 200 years. 1861 is the year of its opening. "G" denotes the first half of April, and "1" means Thatcher was the first comet discovered during that period.

Comet Swift-Tuttle

Comet Swift-Tuttle Comet 109P/Swift-Tuttle takes 133 years to complete one revolution around the Sun. The comet passed its last perihelion (closest point to the Sun) in 1992 and will return again in 2125.

Comet Swift-Tuttle is considered a large comet - its nucleus is 26 km (16 miles) across. (That is, more than twice the size of the supposed object that killed off the dinosaurs.) Chunks of space debris ejected from Comet Swift-Tuttle and interacting with our atmosphere create the popular Perseid meteor shower. This annual meteor shower occurs every August and peaks in the middle of the month. Giovanni Schiaparelli was the first to realize that the source of the Perseids was this comet.

Comet Swift-Tuttle was discovered in 1862 independently by Lewis Swift and Horace Tuttle.

Comets are usually named after their discoverer or the observatory/telescope used in the discovery. Since Lewis Swift and Horace Tuttle discovered this comet, it is named after them. The letter "P" means that Comet Swift-Tuttle is a short-period comet. Short-period comets have orbital periods of less than 200 years.

Comet Tempel-Tuttle

Comet 55P/Tempel-Tuttle is a small comet whose nucleus is 3.6 km (2.24 mi) across. It takes 33 years to complete one revolution around the Sun. Comet Tempel-Tuttle passed its perihelion (closest point to the Sun) in 1998 and will return again in 2031.

Chunks of space debris coming from the comet interact with our atmosphere and create the Leonid meteor shower. This is typically a weak meteor shower that peaks in mid-November. Every year, the Earth passes through this debris, which, when interacting with our atmosphere, disintegrates and creates fiery, colorful streaks in the sky.

Comet 55P/Tempel-Tuttle in February 1998

Every 33 years or so, the Leonid meteor shower turns into a full-blown meteor storm, during which at least 1,000 meteors per hour burn up in Earth's atmosphere. Astronomers in 1966 observed a spectacular sight: the remains of a comet crashed into the Earth's atmosphere at a rate of thousands of meteors per minute during a 15-minute period. The last Leonid meteor storm occurred in 2002.

Comet Tempel-Tuttle was discovered twice independently - in 1865 and 1866 by Ernst Tempel and Horace Tuttle, respectively.

Comets are usually named after their discoverer or the observatory/telescope used in the discovery. Since Ernst Tempel and Horace Tuttle discovered it, the comet is named after them. The letter "P" means that Comet Tempel-Tuttle is a short-period comet. Short-period comets have orbital periods of less than 200 years.

Halley's Comet

Comet 1P/Halley is perhaps the most famous comet, having been observed for thousands of years. The comet was first mentioned by Halley in the Bayeux Tapestry, which recounts the Battle of Hastings in 1066.

Halley's Comet takes about 76 years to complete one revolution around the Sun. The comet was last seen from Earth in 1986. That same year, an international armada of spacecraft converged on the comet to collect as much data as possible about it.

Halley's Comet in 1986

The comet will not arrive into the solar system until 2061. Every time Halley's Comet returns to the inner Solar System, its core sprays ice and rock into space. This debris flow results in two weak meteor showers: the Eta Aquarids in May and the Orionids in October.

Dimensions of Comet Halley: 16 x 8 x 8 km (10 x 5 x 5 miles). This is one of the darkest objects in the solar system. The comet has an albedo of 0.03, meaning it reflects only 3% of the light that hits it.

The first sightings of Halley's Comet are lost in time, more than 2,200 years ago. However, in 1705, Edmond Halley studied the orbits of previously observed comets and noted some that appeared to appear again and again every 75-76 years. Based on the similarity of orbits, he proposed that it was in fact the same comet, and correctly predicted the next return in 1758.

Comets are usually named after their discoverer or the observatory/telescope used in the discovery. Edmond Halley correctly predicted the return of this comet - the first prediction of its kind and that is why the comet is named after him. The letter "P" means that Halley's Comet is a short-period comet. Short-period comets have orbital periods of less than 200 years.

Comet C/2013 US10 (Catalina)

Comet C/2013 US10 (Catalina) is an Oort Cloud comet discovered on October 31, 2013 by the Catalina Sky Survey Observatory with an apparent magnitude of 19, using the 0.68-meter (27 in) Schmidt-Cassegrain Telescope. As of September 2015, the comet has an apparent magnitude of 6.

When Catalina was discovered on October 31, 2013, the preliminary determination of its orbit used observations of another object made on September 12, 2013, which gave an incorrect result suggesting an orbital period of only 6 years for the comet. But on November 6, 2013, with a longer observation of the arc from August 14 to November 4, it became obvious that the first result on September 12 was obtained at a different object.

By early May 2015, the comet had an apparent magnitude of 12 and was 60 degrees away from the Sun as it moved further into the southern hemisphere. The comet came to solar conjunction on November 6, 2015, when it was around magnitude 6. The comet approached perihelion (closest approach to the Sun) on November 15, 2015 at a distance of 0.82 AU. from the Sun and had a speed of 46.4 km/s (104,000 mph) relative to the Sun, slightly faster than the Sun's receding velocity at that distance. Comet Catalina crossed the celestial equator on December 17, 2015 and became a northern hemisphere object. On January 17, 2016, the comet will pass 0.72 astronomical units (108,000,000 km; 67,000,000 mi) from Earth and should be magnitude 6, located in the constellation Ursa Major.

Object C/2013 US10 is dynamically new. It came from the Oort Cloud from a loosely coupled, chaotic orbit that could easily be disturbed by galactic tides and traveling stars. Before entering the planetary region (around 1950), Comet C/2013 US10 (Catalina) had an orbital period of several million years. After leaving the planetary region (around 2050), it will be on an ejection trajectory.

Comet Catalina is named after the Catalina Sky Survey, which discovered it on October 31, 2013.

Comet C/2011 L4 (PANSTARRS)

C/2011 L4 (PANSTARRS) is a non-periodic comet discovered in June 2011. It was only noticed with the naked eye in March 2013, when it was near perihelion.

It was discovered using the Pan-STARRS (Panoramic Survey Telescope and Rapid Response System) telescope located near the top of Halikan on the island of Maui in Hawaii. Comet C/2011 L4 probably took millions of years to travel from the Oort cloud. After leaving the planetary region of the Solar System, the post-perihelion orbital period (epoch 2050) is estimated to be approximately 106,000 years. Made from dust and gas, this comet's nucleus is about 1 km (0.62 miles) in diameter.

Comet C/2011 L4 was at a distance of 7.9 AU. from the Sun and had a brilliance of 19 stars. Vel., when she was discovered in June 2011. But already at the beginning of May 2012 it revived to 13.5 stars. Vel., and this was visible visually when using a large amateur telescope from the dark side. As of October 2012, the coma (an expanding thin dust atmosphere) was about 120,000 kilometers (75,000 mi) in diameter. Without optical assistance, C/2011 L4 was seen on February 7, 2013 and had a magnitude of 6. led Comet PANSTARRS was observed from both hemispheres in the first weeks of March, and it passed closest to Earth on March 5, 2013 at a distance of 1.09 AU. It approached perihelion (closest approach to the Sun) on March 10, 2013.

Preliminary estimates predicted that C/2011 L4 would be brighter, at about 0 magnitude. led (approximate brightness of Alpha Centauri A or Vega). Estimates from October 2012 predicted that it could be brighter, at -4 magnitude. led (roughly corresponds to Venus). In January 2013, there was a noticeable drop in brightness, which suggested that it could be brighter, having only +1 magnitude. led In February the light curve showed a further slowdown, suggesting a perihelion at +2 mag. led

However, a study using a secular light curve indicates that Comet C/2011 L4 experienced a "braking event" when it was at a distance of 3.6 AU. from the Sun and had 5.6 AU. The rate of increase in brightness decreased, and the magnitude at perihelion was predicted to be +3.5. For comparison, at the same perihelion distance, Halley's Comet would have a magnitude of -1.0. led The same study concluded that C/2011 L4 is a very young comet and belongs to the class of “children” (that is, those whose photometric age is less than 4 years of the comet).

Image of Comet Panstarrs taken in Spain

Comet C/2011 L4 reached perihelion in March 2013, and was estimated to have an actual peak of +1 magnitude by various observers around the planet. led However, its low location above the horizon makes it difficult to obtain certain data. This was facilitated by the lack of suitable reference stars and the impossibility of differential atmospheric extinction corrections. As of mid-March 2013, due to the brightness of twilight and its low position in the sky, C/2011 L4 was best visible through binoculars 40 minutes after sunset. On March 17-18, the comet was close to the star Algenib with 2.8 stars. led April 22 near Beta Cassiopeia, and May 12-14 near Gamma Cepheus. Comet C/2011 L4 continued to move north until May 28th.

Comet PANSTARRS bears the name of the Pan-STARRS telescope, with which it was discovered in June 2011.

Comets of the Solar System have always been of interest to space researchers. The question of what these phenomena are also worries people who are far from studying comets. Let's try to figure out what this celestial body looks like and whether it can influence the life of our planet.

The content of the article:

A comet is a celestial body formed in Space, the size of which reaches the scale of a small settlement. The composition of comets (cold gases, dust and rock fragments) makes this phenomenon truly unique. The comet's tail leaves a trail of millions of kilometers. This spectacle fascinates with its grandeur and leaves more questions than answers.

The concept of a comet as an element of the solar system

Let's take a closer look at the features of comets:

• Comets are so-called snowballs that pass through their orbit and contain dusty, rocky and gaseous accumulations.
• The celestial body warms up during the period of approach to the main star of the solar system.
• Comets do not have satellites that are characteristic of planets.
• Formation systems in the form of rings are also not typical for comets.
• It is difficult and sometimes unrealistic to determine the size of these celestial bodies.
• Comets do not support life. However, their composition can serve as a certain building material.

Features of the structure of comets

The description of a comet can be divided into characteristics of the nucleus, coma and tail of the object. This suggests that the celestial body under study cannot be called a simple structure.

Comet nucleus

There are 3 theories that consider the structure of comet nuclei differently:

1. The "dirty snowball" theory. This assumption is the most common and belongs to the American scientist Fred Lawrence Whipple. According to this theory, the solid part of the comet is nothing more than a combination of ice and fragments of meteorite matter. According to this specialist, a distinction is made between old comets and bodies of a younger formation. Their structure is different due to the fact that more mature celestial bodies repeatedly approached the Sun, which melted their original composition.
2. The core is composed of dusty material. The theory was announced at the beginning of the 21st century thanks to the study of the phenomenon by the American space station. Data from this exploration indicate that the core is a dusty material of a very friable nature with pores occupying the majority of its surface.
3. The core cannot be a monolithic structure. Further hypotheses diverge: they imply a structure in the form of a snow swarm, blocks of rock-ice accumulation and meteorite accumulation due to the influence of planetary gravity.

Comet coma

Three levels of coma can be defined, which look like this:

• Interior chemical, molecular and photochemical composition. Its structure is determined by the fact that the main changes occurring with the comet are concentrated and most activated in this area. Chemical reactions, decay and ionization of neutrally charged particles - all this characterizes the processes that occur in an internal coma.
• Coma of radicals. It consists of molecules that are active in their chemical nature. In this area there is no increased activity of substances, which is so characteristic of an internal coma. However, here too the process of decay and excitation of the described molecules continues in a calmer and smoother mode.
• Coma of atomic composition. It is also called ultraviolet. This region of the comet's atmosphere is observed in the hydrogen Lyman-alpha line in the distant ultraviolet spectral region.

Comet tail

Fedor Bredikhin proposed classifying sparkling plumes into the following subspecies:

1. Straight and narrow format tails. These components of the comet are directed from the main star of the solar system.
2. Slightly deformed and wide-format tails. These plumes are evading the Sun.
3. Short and severely deformed tails. This change is caused by a significant deviation from the main star of our system.

• Dust tail. A distinctive visual feature of this element is that its glow has a characteristic reddish tint. A plume of this format is homogeneous in its structure, stretching for a million, or even tens of millions of kilometers. It was formed due to numerous dust particles that were thrown away by the energy of the Sun over a long distance. The yellow tint of the tail is due to the dispersion of dust particles by sunlight.
• Tail of the plasma structure. This plume is much more extensive than the dust trail, because its length is tens and sometimes hundreds of millions of kilometers. The comet interacts with the solar wind, which causes a similar phenomenon. As is known, solar vortex flows are penetrated by a large number of fields of a magnetic nature. They, in turn, collide with the comet's plasma, which leads to the creation of a pair of regions with diametrically different polarities. At times, this tail breaks off spectacularly and a new one is formed, which looks very impressive.
• Anti-Tail. It appears according to a different pattern. The reason is that it is directed towards the sunny side. The influence of the solar wind on such a phenomenon is extremely small, because the plume contains large dust particles. It is possible to observe such an antitail only when the Earth crosses the comet’s orbital plane. The disc-shaped formation surrounds the celestial body on almost all sides.

Main types of comets

1. Short-period comets. The orbital time of such a comet does not exceed 200 years. At their maximum distance from the Sun, they have no tails, but only a subtle coma. When periodically approaching the main luminary, a plume appears. More than four hundred such comets have been recorded, among which there are short-period celestial bodies with a revolution around the Sun of 3-10 years.
2. Comets with long orbital periods. The Oort cloud, according to scientists, periodically supplies such cosmic guests. The orbital term of these phenomena exceeds the two hundred year mark, which makes the study of such objects more problematic. Two hundred and fifty such aliens give reason to believe that in fact there are millions of them. Not all of them are so close to the main star of the system that it becomes possible to observe their activities.

The most famous comets of the solar system

There are a large number of comets that pass through the solar system. But there are the most famous cosmic bodies that are worth talking about.

Halley's Comet

Of course, some long-period comets are more spectacular, but 1P/Halley can be observed even with the naked eye. This factor makes this phenomenon unique and popular. Almost thirty recorded appearances of this comet pleased outside observers. Their frequency directly depends on the gravitational influence of large planets on the life activity of the described object.

The speed of Halley's comet in relation to our planet is amazing because it exceeds all indicators of the activity of the celestial bodies of the Solar System. The approach of the earth's orbital system to the comet's orbit can be observed at two points. This results in two dusty formations, which in turn form meteorite showers called the Aquarids and Oreanids.

If we consider the structure of such a body, it is not much different from other comets. When approaching the Sun, the formation of a sparkling trail is observed. The comet's nucleus is relatively small, which may indicate a pile of debris as building material for the object's base.

You will be able to enjoy the extraordinary spectacle of the passage of Halley's Comet in the summer of 2061. It promises better visibility of the grandiose phenomenon compared to the more than modest visit in 1986.

The phenomenality of this discovery lies in the fact that in the late 90s the comet was observed without special equipment for ten months, which in itself cannot but surprise.

The shell of the solid core of a celestial body is quite heterogeneous. Icy areas of unmixed gases are combined with carbon monoxide and other natural elements. The discovery of minerals that are characteristic of the structure of the earth's crust and some meteorite formations once again confirm that Comet Hale-Bop originated within our system.

The influence of comets on the life of planet Earth

The Icelandic volcano Eyjafjallajokull began its active and destructive two-year activity, which surprised many scientists of the time. This happened almost immediately after the famous Emperor Bonaparte saw the comet. This may be a coincidence, but there are other factors that make you wonder.

The previously described Comet Halley strangely affected the activity of such volcanoes as Ruiz (Colombia), Taal (Philippines), Katmai (Alaska). The impact of this comet was felt by people living near the Cossuin volcano (Nicaragua), which began one of the most destructive activities of the millennium.

Comet Encke caused a powerful eruption of the Krakatoa volcano. All this may depend on solar activity and the activity of comets, which provoke some nuclear reactions when approaching our planet.

Comet impacts are quite rare. However, some experts believe that the Tunguska meteorite belongs to just such bodies. They cite the following facts as arguments:

• A couple of days before the disaster, the appearance of dawns was observed, which, with their diversity, indicated an anomaly.
• The appearance of such a phenomenon as white nights in unusual places immediately after the fall of a celestial body.
• The absence of such an indicator of meteoricity as the presence of solid matter of a given configuration.

What a comet looks like - look at the video:

will help study small objects of the solar system. You will discover a lot of new and useful things, so many secrets are kept by the relative silence of the universe, which is in constant movement and development.

1. A comet is a cosmic body that exists within the Solar System, moving in orbit around the Sun. Comets appeared with the emergence of the solar system four and a half billion years ago..
2. The name is of Greek origin. “Comet” is a Greek word that means “long-tailed”, since this is the body that has long been associated with people whose hair fluttered in a strong wind. The closest point of the orbit in relation to the Sun is perihelion, the farthest is aphelion.

   

3. Comet - dirty snow. Chemical composition: water, methandrostenolone, frozen ammonia, dust, stones, space debris. The tail part appears when it is closest to the Sun. At a considerable distance it looks like a dark object, representing a clot of ice. The central part is represented by a stone core. It has a dark surface, its composition is precisely unknown.

   

4. As the comet approaches the Sun, it heats up and melts. Melting ice as it approaches the sun leads to the formation of a dust cloud, which creates a tail effect. When approaching the luminary, the body heats up, causing the process of sublimation. When ice is close to the surface, it heats up and creates a jet, erupting like a geyser.

   

5. There are many comets. The smallest of them has a core with a diameter of sixteen kilometers, the largest - forty. The size of the tail reaches enormous sizes. Hyakutake has a tail of five hundred and eighty million kilometers. In the “Oort Cloud” that envelops space, several trillion copies can be counted. There are about four thousand comets in total.

   

6. Jupiter can influence the movement of comets. The largest planet is able to influence the direction of movement of these celestial bodies. The planet's gravitational force is so strong that Shoemaker Levy 9 was destroyed when it hit the planet's atmosphere.

   

7. Under the influence of gravity, a tailed comet takes on the shape of a sphere.. The asteroid is quite small to form a sphere, resembling a dumbbell shape. Asteroids accumulate in piles, containing materials of various origins. The largest, Casetere, is nine hundred and fifty kilometers in diameter. An asteroid that enters the planetary atmosphere is called a meteor; when it falls to the ground, it is a meteorite.

   

8. Comet is a potential threat to earthlings. Our civilization could be destroyed by a meteor with a diameter of one kilometer. Continued research is needed to understand the nature of tailed insects and to develop optimal methods of protection against them. Even in ancient times, these bodies were considered a sign that could bring disaster.

   

9. Halley's Comet periodically visits the solar system. In 1910, Comet Halley passed close to the Earth, which enters the solar system every 76 years. Some enterprising businessmen used this fact to increase the number of sales of gas masks, comet remedies, and umbrellas.

   

10. Comets usually have two tails. The first, dust, can be observed with the naked eye. The second tail consists of gases, stretching up to three hundred and sixty miles. The ion tail is the result of the influence of the solar wind. The orbit of comets resembles an elliptical shape. As the body approaches the Sun, the icy component begins to heat up, causing evaporation. The gases and dust form a cloud called a coma, which moves behind the body. As it moves towards the star, dust and debris are blown off the body, forming a dust tail.

    

11. The farther from the Sun, the more the comet is an ordinary stone block. The gas tail becomes visible under the influence of solar radiation. As it moves away from the Sun, the body cools, leaving only an icy core.

    

12. Scientists suggest that comets brought water to Earth. Water could have come to the globe from a comet, as well as many organic substances. They were the means of the origin of life.

    

13. Some scientists believe that sixty-five million years ago a large asteroid may have touched the surface, causing the dinosaurs to become extinct.

    

14. Comets are subject to extinction or departure from the solar system. They leave the system or melt as they are repeatedly exposed to heat.

    

15. Only once a decade can we observe a comet in the sky. The comet's tail can be observed for several days or even weeks.