100 great mysteries of astronomy Volkov Alexander Viktorovich

Does the planet Vulcan exist?

Does the planet Vulcan exist?

A century and a half ago, the planet Vulcan was discovered, whose orbit was located between Mercury and the Sun. Subsequently, Albert Einstein proved that this celestial body should not exist. However, more than half a century later, the planet Vulcan appeared in the popular television series Star Trek. Is her mystery still not solved? The mystery of this hypothetical planet, discovered at the tip of a pen by an astronomer who had previously become famous for another similar prediction?

So, in 1846, the French scientist Urbain Jean Joseph Le Verrier, having studied the peculiarities of the movement of Uranus, calculated the orbit and position of the neighboring planet, which was not yet known, which was called Neptune. A few years later, his attention was drawn to some oddities in the behavior of the planet closest to the Sun - Mercury. Its orbit was not at all perfectly elliptical. This means that, having completed a revolution around the Sun, Mercury did not return to its starting point. In other words, with each new revolution its perihelion, that is, the point of its orbit closest to the Sun, shifted slightly.

The French mathematician Le Verrier, studying the deviations of the orbit of Mercury, suggested the existence of a planet, which he gave the name “Vulcan”

A similar phenomenon is typical for all planets in the solar system. It is caused by the attraction of nearby celestial bodies. In the case of Mercury, it is “pulled” towards itself by Venus, Earth, Mars and Jupiter. The perihelion point slowly rotates around the Sun (today it is known that it completes a full revolution in more than 225 thousand years). Over one century, the rotation of perihelion is 574 arc seconds (in one degree - 3600 arc seconds). However, if we take into account the influence of the known planets - and Le Verrier meticulously noted all the positions of perihelion - then this value should be equal to 531 seconds. Strangely, the perihelion of Mercury “ran” forward by 43 seconds every hundred years.

Apparently, somewhere nearby, between Mercury and the Sun, there was another planet that had not yet been discovered. The famous astronomer named this celestial body, literally bathed in solar fire, “Vulcan” in honor of the Roman god of fire. (To be fair, it must be said that the results of the calculations carried out by Le Verrier were, in today’s opinion, not entirely accurate, but they correctly conveyed the essence of the phenomenon - an inexplicable shift in the perihelion).

Le Verrier published the results of his calculations in September 1859, and soon after, the French physician and amateur astronomer Edmond Lescarbault told him that on March 26, 1859, he saw a round black spot on the Sun, which in just 75 minutes moved to a distance exceeding a quarter of the solar diameter . Le Verrier went to his correspondent and got acquainted with the information he had collected. This allowed him to determine that the unknown planet revolved around the Sun in 19 days and 7 hours. Its average distance from the Sun was 21 million kilometers, equal to about a third of the radius of Mercury's orbit, and its mass was 17 times less than its mass. Le Verrier became convinced that the planet discovered by his colleague was too small to explain the features of Mercury's orbit. However, it could be only one of several planets located near the Sun.

Other astronomers also responded to this event. Thus, researcher from Zurich Rudolf Wolf reported his observations. This allowed Le Verrier to discover two more small planets near the Sun. The circulation period of one of them was 26 days, and the second – 38 days.

The New Year of 1860 was supposed to be a triumph for the French master. He was confident that during a total solar eclipse, which was expected in Spain, these planets, discovered by calculations, could finally be seen, but this did not happen. Is it really a fiasco?

A debate ensued among astronomers. Some still mistook any suspicious spots on the Sun for a mysterious planet that had passed the solar disk, while others denied its right to exist.

Until his death in 1877, Le Verrier was convinced that the planet Vulcan could be found. However, after many years of unsuccessful searches, most astronomers have lost faith in this.

The riddle of the planet Vulcan was finally solved on November 18, 1915. It was on this day that Albert Einstein published his explanation for the strange behavior of Mercury. What seemed incomprehensible from the point of view of Newtonian mechanics found its interpretation as soon as one turned to the general theory of relativity.

According to it, the Sun “curves” space and distorts the orbits of planets. If we describe the movement of Mercury in Euclidean space according to Newton's laws of mechanics, it seems that it is moving too fast. However, if we turn to non-Euclidean geometry and Einstein's theory, the strangeness disappears. The difference in these calculations is the same 43 arc seconds that prompted Le Verrier to come up with the planet Vulcan. Now she had to be written off as unnecessary.

Interest in Le Verrier's hypothesis was briefly aroused in 1970, when, during a total solar eclipse, some researchers discovered some strange, faintly luminous objects in the vicinity of the Sun. Astronomers later suggested that these were comets.

So, in the 19th and 20th centuries, researchers observed the planet Vulcan more than once, and now it is unlikely that they will be able to establish what they actually saw. Some "observations" could be explained by a simple defect in the optics. Even a bird flying in the distance could be mistaken for a planet. However, there is a known case when, on the same day, two astronomers living in different cities noticed, independently of each other, an object that was moving across the disk of the Sun. Perhaps it was an asteroid, although science still does not know of a single reliably confirmed case of an asteroid passing across the solar disk.

The planet Vulcan has disappeared from the annals of astronomy to give way to... a whole scattering of planets that deserve the same name. Enthusiasts continue to search for “volcanoids” - small planets whose orbits may be located inside the orbit of Mercury.

In principle, astronomers have no doubt that some asteroids may be found between Mercury and the Sun. It is known that in the distant past, Mercury was subjected to “formal bombardment” - numerous craters left on its surface after the fall of large meteorites remind us of that time. Perhaps the reason for this “shelling” was the proximity to the asteroid belt. Since then, this cluster of small planets has obviously thinned out considerably, but perhaps several of these planets are still circling the Sun in close proximity to it?

So what do we know about vulcanoids, even if we have not yet been able to detect them? Obviously, these are very small planets, not exceeding fifty kilometers in diameter. Larger celestial bodies orbiting near the Sun would certainly be noticed by the SOHO solar observatory. The distance at which they should be looked for is also known. Probably, the belt of circumsolar asteroids, if any, is located in the range of 0.15-0.18 astronomical units from the Sun, that is, almost next to it. Their surface temperatures are expected to be between 700 and 900 Kelvin. However, despite persistent searches, within the orbit of Mercury it has so far been possible to notice only individual asteroids, which, moving along very elongated trajectories, for some time approached the Sun closer than this planet. To where they would meet the Vulcanoids? Or not?

This text is an introductory fragment.

Volcanoes of the Decade are mountain peaks that, according to the International Association of Volcanology and Chemistry of the Earth's Interior, deserve careful and thorough study. The need to study volcanoes is primarily due to their proximity to large populated areas and a rich history filled with many destructive eruptions. The Volcanoes of the Decade Project was launched on January 1, 1990, at the initiative of the United Nations as part of the International Decade for Natural Disaster Reduction.

Selection criteria for Volcanoes of the decade

According to the project, the list can only include the most dangerous volcanoes that meet the following criteria:

• pyroclastic flows;
• lava flows;
• lahars;
• tephra fall;
• structural volcanic instability;
• recent geological activity;
• high probability of death of tens or hundreds of thousands of people;
• destruction of the lava dome.

List of Volcanoes of the Decade

Today, these include 16 peaks located in different parts of the world:

1. Avachinskaya Sopka, Russia. The 2741 m high volcano is located in the southern part of Kamchatka and is composed of slag, andesite and basalt lava. It has erupted 18 times over the past three centuries, with the last explosion in 1991 leaving a large plug of lava in its 400-meter crater that could burst out at any moment.

2. Colima, Mexico. Located in the Mexican Volcanic Sierra, the peak has an altitude of 3850 m and consists of two conical peaks, one of which is active. Since 1576, over 40 eruptions have been recorded; during the last one, in 2015, a column of ash and smoke rose to a height of about 10 km.

3. Galeras, Colombia. The mountain rises near the city of Pasto and is a constant threat to its 400,000 population. The height of the volcano is 4276 m, the diameter of the crater is 320 m. Over 7,000 years it has experienced at least 6 powerful eruptions and countless small ones. During the last volcanic activity in 2010, local authorities had to evacuate more than 9,000 people.

4. Mauna Loa, Hawaii, USA. The shield volcano in Hawaii rises 4169 m above the sea and is considered the largest in volume among all active peaks on our planet. Since the 1830s, 39 eruptions have been recorded, the most recent occurring in 1984.

5. Etna, Italy. Beautiful is the highest active volcano in Europe and one of the most active. It once caused the almost complete destruction of Catania, and now on average every 3 months it pours out lava from its numerous craters.

6. Merapi, Indonesia. The most active Indonesian volcano is located on the island of Java and erupts at intervals of about six months. Every seven years it has a powerful eruption, and emits smoke almost every day. During the 2010 eruption, more than 190 residents of surrounding villages became victims of the volcano.

7. Nyiragongo, Congo. Of all the observed eruptions in Africa, this volcano and the neighboring peak Nyamlagila account for about 40% of the continent's volcanic activity. has a large 250-meter crater from which it emits incredibly liquid lava from time to time. Due to the low quartz content, this lava is capable of flowing down slopes at speeds of up to 100 kilometers per hour.

8. Rainier, USA. According to the US Geological Survey, more than 150 thousand people could be affected by the volcano. rises 88 km from Seattle and is currently classified as dormant, although at least 6 eruptions were recorded in the 19th century.

9. Vesuvius, Italy. The most terrible event in the history of the volcano happened in 79, when several cities of Campania, including Pompeii and Herculaneum, were destroyed by pyroclastic and mudflows. The last time it erupted was in 1944, when 27 people were injured and the towns of Massa and San Sebastiano were destroyed.

10. Unzen, Japan. The volcanic eruption in 1792 was one of the five most destructive in human history. When the mountain exploded, a 55-meter tsunami was generated, killing over 15 thousand people.

11. Sakurajima, Japan. The volcano is located on the island of Kyushu and is considered a tourist attraction, but the cities of Tarumizu and Kagoshima are located next to it, so if it erupts, the disaster will affect at least 600 thousand people.

12. Santa Maria, Guatemala. One of the most terrible volcanoes in the country. Until the beginning of the 20th century, it did not erupt for over 500 years. In 1902, as a result of the big explosion, about 5 cubic meters were thrown out. km of tephra and killed 6,000 people.

13. Santorini, Greece. The volcanic eruption, dating back to around 1645 BC, caused the disappearance of the Minoan culture on Crete and led to an 18 m high tsunami that washed away all coastal settlements.

14. Taal, Philippines. Active on the island of Luzon, it is known for its eruption in 1911, when pyroclastic flows literally destroyed everything up to 10 km away, including more than 1,300 people, in just 8–10 minutes.

15. Teide, Canary Islands, Spain. During an explosion in 1706, the volcano destroyed the city of Garachico and a number of villages. The last volcanic activity dates back to 1909.

16. Ulawun, Papua New Guinea. The highest peak in the Bismarck Archipelago is considered the most active in the country and is famous for its 1915 eruption, which left the nearby town of Toriu covered in 10 centimeters of ash.

Our solar system holds many still unsolved mysteries. One of them has been exciting the minds of astronomers and space researchers for a century and a half. Are there small planets inside the orbit of Mercury, hidden from the human eye by the radiant corona of the Sun? After all, the laws of celestial mechanics allow the presence of planets so close to the Sun.

In recent years, astronomers have been able to discover hundreds of giant planets in other star systems, similar in their characteristics to our Jupiter, Saturn or Neptune. But the distinctive feature of such giants was that these celestial bodies were very close to their central stars. The orbits of most of them could easily fit inside the orbit of Mercury. Naturally, the temperature of such planets is much higher than the temperature of the planets of our Solar System, in which nothing of the kind is observed. Therefore, these classes of gas giants were called hot Jupiters, Saturns or Neptunes, depending on their similarity to the planets of our solar system. Thus, the fact of the existence of hot giants clearly confirms the fundamental possibility of the presence of planets at very close distances to their central stars.

***

History of the search for the planet Vulcan

The history of the search for small intramercurial planets dates back to the middle of the 19th century. This was the time of triumph of natural philosophy, born two centuries earlier. It seemed to scientists then that many celestial phenomena could be successfully explained if we imagined the world in which we live as a huge machine, the operation of which obeys Newton’s laws.

In 1840, François Arago, director of the Paris Observatory, proposed to the French mathematician Urbain Jean Joseph Le Verrier to develop a theory of the orbital motion of Mercury around the Sun. Le Verrier successfully completed this task, but it later turned out that the observational results differed significantly from theoretical calculations. In 1846, Le Verrier gained fame and respect from the scientific community by calculating the exact location of the planet Neptune. As they say now, Le Verrier discovered Neptune “at the tip of his pen.”

Urbain Le Verrier

After this triumph, Le Verrier returned to solving the problem of Mercury's orbital motion. The essence of the problem was that his previously developed theory of the movement of Mercury, based on Newtonian celestial mechanics, did not agree well with long-term observational results. Le Verrier's calculations could not explain the movement of the perihelion (the point of the orbit closest to the Sun) of Mercury. The perihelion displacement was 43 arcseconds per century. It was logical to assume that, as in the case of Uranus and Neptune, the discrepancy between observations and theory was caused by the existence of an as yet unknown planet located inside the orbit of Mercury. With its gravitational field, this unknown planet could cause disturbances in the movement of Mercury in its orbit. In theory, this hypothetical planet should have been so close to the Sun that it could only be noticed at the moment when it passed across the disk of the Sun or at a very short distance from our luminary during solar eclipses on Earth.

First, Le Verrier tried to find out whether the presence of asteroids, comets and cosmic dust in this region of space was the cause of the existing disturbances in the movement of Mercury. He believed that if there were enough such objects, they would form a visible ring around the Sun, similar to the rings of Saturn. However, at that time, no dense rings around the Sun were discovered (the dust ring was discovered only in 1983). All that remained was to look for the invisible planet influencing the movement of Mercury.

In 1859, Le Verrier received a letter from the amateur astronomer Lescarbo, who reported that on March 25 he observed a round dark spot similar to a planet moving across the disk of the Sun. Le Verrier immediately went to Lescarbot to personally question him about the discovered celestial body. In addition to Lescarbot's data, Le Verrier selected the results of five other observations, which, in his opinion, could not be attributed to cases of the passage of Mercury or Venus across the solar disk. Based on these six observations, he calculated the orbit of the invisible planet in 1859, which he called Vulcan .

According to his calculations, the period of revolution of Vulcan around the Sun was 19 days and 7 hours, the average distance from the Sun is approximately 0.143 astronomical units (AU), and the mass is 1/12 from the mass of Mercury. Let us remind our readers that the average distance of Mercury from the Sun is 0.387 AU. Of course, Le Verrier understood that such a small mass was not enough to cause the observed perturbations in Mercury's orbit. However, despite this, it was necessary to begin the search for the invisible planet. In 1860, a total solar eclipse was about to occur, and Le Verrier mobilized almost all astronomers in France to search for Vulcan. However, none of them were able to detect this hypothetical planet.

In 1877, Le Verrier dies without waiting for the discovery of the fiery Vulcan. But during the eclipse of July 29, 1878, the ghost planet was observed by several astronomers at once. University of Michigan astronomy professor James Watson said he observed as many as two planets within the orbit of Mercury. Another astronomer, Lewis Swift, who discovered the comet named after him, also stated that he saw a luminous object similar to a planet. However, it turned out that the orbits calculated from these observations did not coincide either with each other or with the orbit once calculated by Le Verrier. Naturally, such observational results could not be taken seriously by the scientific community.

Years passed, but the observations did not bring success. Gradually, astronomers' faith in the existence of the hypothetical Vulcan began to fade. After the publication of Albert Einstein's Special Theory of Relativity in 1916, the existence of Vulcan was no longer necessary for modern astronomy, since the disturbances in the movement of Mercury could be elegantly explained using this theory. In other words, the new theory solved the old puzzle without any need for Vulcan. The systematic search for the ghost planet was stopped, and official astronomy put an end to this matter.

Vulcanoids

What did Lescarbo, Watson, Swift and other astronomers observe? Currently, astronomical science accepts the existence of asteroids within the orbit of Mercury. Such hypothetical celestial bodies were even dubbed vulcanoids in honor of the never discovered planet Vulcan. According to theoretical calculations, such asteroids can have their orbits in a dynamically stable zone between 0.08 and 0.21 AU. from the sun. It is believed that if volcanoids exist, their diameter should not exceed 60 km, since larger objects would have been discovered earlier. Despite the fact that space telescopes are now constantly monitoring the Sun in various wavelength ranges, vulcanoids have not yet been discovered. The bright photosphere of the Sun brings enormous difficulties to the process of searching for asteroids. However, some astronomers are optimistic about the future because the search area is gravitationally stable. For further searches, small space-based telescopes capable of observing the circumsolar space will most likely be used.

Of course, it is possible that astronomers of the 19th century could observe the passage of comets in close proximity to the Sun during solar eclipses. A whole class of such solar comets is currently known. For example, the SOHO solar space telescope has already discovered more than 2,000 such comets. However, the nuclei of such comets are small, and detecting them using the relatively imperfect telescopes of those times was very problematic.

Despite the fact that the search for Vulcan has not yet brought any results, some scientists are still serious about solving this problem. For example, a professor of astronomy from Long Island, G. Corten, at one time reported his discovery of a new celestial body or group of bodies inside the orbit of Mercury. According to him, in the photographs he took during the solar eclipses of 1966 and 1970, some mysterious traces of some celestial body are clearly visible. The professor believed that these traces could not be associated with the passage of comets near the Sun. Korten considered the gravitational influence of a small planet or asteroid with a diameter of about 300 km as the main cause of the observed disturbances in the movement of Mercury.

In November 1971, the Daily Telegraph published a sensational report that astronomers at the University of Cambridge and the Naval Observatory in Washington had allegedly discovered a new planet located between Mercury and the Sun. However, the explanation for this fact was very vague and vague. According to the newspaper, this assumption was made based on an analysis of changes in the orbits of other planets in the solar system. It is clear that the scientific community was very skeptical about such publications.

As mentioned above, in 1983, Japanese astronomers managed to discover a relatively dense ring of dust around the Sun. The radius of the ring was approximately 4 times the radius of the Sun. According to calculations, the mass of the ring was several million tons, and the temperature of the particles reached 1000 degrees.

Disputes over the existence of hypothetical intramercurial planets continue to this day. Some researchers provide their own calculation data based on the Titius-Bode relation and Kepler's 3rd law. For example, Gromov R.G. in his work “Harmony in the Solar System” showed the theoretical possibility of the existence of two small intramercurial planets. One of them should be 0.22 AU away from the Sun. and have a circulation period of 35.2 days, for the second the removal is 0.11 AU. and a period of 14.1 days. Other researchers believe that the distance of the hypothetical Vulcan from the Sun should be 0.25-0.26 AU, and the orbital period should be 19 - 50 days. Let us remind our readers that according to Le Verrier’s calculations, the average distance of Vulcan from the Sun should be equal to 0.143 AU, and the orbital period should be 19.29 days.

***

At the very beginning of our essay, we already talked about the discovery in recent years of a whole class of exoplanets - hot giants. A typical hot Jupiter is usually separated from its central star by a distance of the order of 0,04 — 0,05 AU, and the circulation period is only a few days. Such huge planets could easily fit inside the orbit of Mercury. It is clear that the configuration of planetary systems in space can be very diverse, and the problem of hot Jupiters itself is still a mystery for astronomy. However, the very fact of the existence of such planets at such small distances from their stars strengthens the confidence of a number of astronomers and researchers that hypothetical intramercurial planets can still be discovered in our Solar System in the near future. It is still too early to put an end to this matter.

P.S. 11 March turned 203 anniversary of the birth of the outstanding French astronomer Urbena Le Verrier, member of the Paris Academy of Sciences, director of the Paris Astronomical Observatory (1854 - 1877).

Planets and satellites of planets with extinct and active volcanic activity: Io, Earth, Mars, Moon, Venus, Mercury

Planets with active volcanic activity

Although there are traces of volcanic activity and volcanic rocks on all the “terrestrial-type” planets included in the composition (and on many satellites of the gas giant planets), active volcanism is currently observed only in two of its celestial bodies - our planet Earth and the satellite of Jupiter - And about.

Volcanoes of planet Earth

Volcanic processes occurring on Earth are quite well studied and described by many researchers. In total, over 800 active volcanoes are known on the surface of the Earth, two-thirds of them are concentrated on the shores and islands of the Pacific Ocean. There are also a huge number of extinct volcanoes on Earth. At the bottom of the Pacific Ocean alone, there are currently about 1,000 mountains of volcanic origin more than 1 km high. It will not be wrong to say that almost all, or almost all, seamounts are volcanoes.

The largest volcanoes on Earth are:

• Kilimanjaro (5895 m) in Africa
• Cotopaxi (5897 m) in South America
• Misti (5821 m) in South America
• Orizaba (5700 m) in Mexico
• Popocatepetl (5452 m) in Mexico
• Klyuchevskaya Sopka (4835 m) in Kamchatka
• Mauna Kea (4205 m) in the Hawaiian Islands

The annual “productivity” of all active volcanoes on Earth is 3-6 billion tons of erupted matter. This means that from the depths of the Earth a huge amount of molten material with a temperature of over 1000 ° C comes to the surface every year: ash, slag, volcanic bombs, erupted lava flows, etc.

Thus, volcanism is a very important process in the formation of the outer shell of the Earth.

Volcanoes of Jupiter's moon Io

The second body of the solar system on which modern active volcanic activity has been reliably established is the closest satellite of Jupiter - And about.

Its diameter is 3640 km, which is approximately 150 km larger than the diameter of the Moon. The surface of this moon is marked with dark craters, around which lava flows are usually visible. A number of images obtained from automatic space stations revealed clear traces of active volcanism. Pale greenish-white clouds of volcanic emissions extended to altitudes of 100-280 km. The emission speed reached 1 km/s. The caldera of one of the volcanoes is a ring structure with a diameter of about 300 km.

Even the simplest analysis of images from the Voyager 1 spacecraft made it possible to detect seven active volcanoes on the surface of Io, which erupted repeatedly during the four days when they were in the field of view of the station’s television cameras. Four months later, during the flight of another station, at least six of the previously discovered volcanoes continued their active volcanic activity.

Volcanic eruption on Io, a satellite of Jupiter.

Volcanic eruptions on Io are explosive in nature. Similar volcanic activity on Earth occurs with the active participation of water vapor. Volcanic explosions during volcanic eruptions on Io are apparently caused by the presence of sulfur dioxide. Scientists believe that Io's interior is almost completely molten due to Jupiter's very active tidal influence, and Io's surface is covered with a layer of sulfur several kilometers thick.

The interaction of the hot interior with the surface layer of sulfur led to the formation of an atmosphere, ionosphere, and the formation of a torus ring consisting of charged particles along the orbit. Its interaction with Jupiter's magnetosphere results in grandiose "auroras."

The first evidence of modern extraterrestrial volcanism suggests that Io is a celestial body much more volcanically active than Earth. Preliminary estimates by scientists studying the intensity of volcanic activity on Io indicate that the surface of this satellite is transforming at a rate of 1 mm per year. This figure is quite impressive on a geological time scale. Constant renewal of the surface occurs as a result of lava outpourings and ejections of material from volcanic vents.

Planets with ceased volcanic activity

Volcanoes on the Moon

As a result of studying numerous photographs of the Moon and direct human study of its surface and soil composition, it was concluded that the Ocean of Storms is composed of ancient volcanic rocks of basic composition -.

Volcanic activity on the Moon ceased about 3 billion years ago. However, there are facts that are sometimes interpreted by individual researchers as signs of modern volcanic activity.

Such “moon holes” are considered traces of lava flows of the past - the lava hardened unevenly, leaving a void underneath. Over time, the dome collapsed, forming a cave.

The relief of the lunar seas and the Ocean of Storms is characterized by the same forms as in the volcanic regions of the Earth. These are lava flows and covers, limiting them with winding ledges, cracks - rillies, volcanic domes. Shafts and ridges are widely developed here, long (10-30 km) and also winding. Their origin is not entirely clear. It is assumed that these may be dykes- igneous rocks frozen in cracks, forming vertical or steeply dipping walls, or projections of the foundation, surrounded by lava.

Radiological determinations show that the age of lunar basalts is measured in the interval of 4-3 billion years.

Volcanoes on Mercury

There is every reason to assume that volcanic rocks are widespread on the surface. Analogues of the lunar seas stand out here, primarily the huge Kaloris depression (Sea of ​​Heat). Its surface is predominantly smooth, but there are curved ledges, reminiscent of the frontal boundaries of lava flows on the Moon.

Unlike the Moon, where the height of the ledges is only tens of meters, on Mercury it reaches 200-500 m. The reason for these differences can be explained by the more viscous composition of Mercury's lavas. It is possible that this is due to the much greater gravity on the surface (more than 2 times) than that of the Moon. The high average density of the planet's rocks gives grounds for assumptions that the sea basins of Mercury may be filled with lavas similar in composition to mantle material.

The Rachmaninoff Basin on Mercury is evidence of the planet's relatively recent volcanism. The flat bottom of this crater was formed from solidified lava.

The age of volcanism on Mercury can be judged by the degree of saturation of its surface with craters. It is assumed that it is close to the time of formation of lunar basalts.

Despite the widespread development of volcanic rocks on the surface of Mercury, volcanic apparatuses of the central type were unknown until recently. Only a thorough analysis of space images made it possible to discover about one and a half dozen objects similar to shield volcanoes and domes. Their heights and diameters are insignificant.

The largest of them is located in the center of the hilly volcanic plain of Odina, located between the Cordillera of the Sultry Mountains (in the west) and the Schiaparelli range (in the east) and has a diameter of 7 km and a height of about 1.5 km.