Neptune is the eighth planet from the Sun and the last known planet. Although it is the third most massive planet, it is only the fourth in terms of diameter. Thanks to its blue color, Neptune received the name of the Roman god of the sea.
As scientific discoveries are made, scientists often have disputes about which theory is trustworthy. The discovery of Neptune is a clear example of such disagreements.
After the planet was discovered in 1781, astronomers noticed that its orbit was subject to significant fluctuations, which in principle should not exist. As a justification for this incomprehensible phenomenon, a hypothesis was proposed about the existence of a planet, the gravitational field of which causes the orbital deviations of Uranus.
However, the first scientific works related to the existence of Neptune appeared only in 1845-1846, when the English astronomer John Couch Adams published his calculations about the position of this then unknown planet. However, despite the fact that he submitted his work to the Royal Scientific Society (the leading English research organization), his work did not attract the expected interest. It was only a year later that French astronomer Jean Joseph Le Verrier also presented calculations that were strikingly similar to Adams's. As a result of independent evaluations of the scientific work of the two scientists, the scientific community finally agreed with their conclusions and began searching for a planet in the area of the sky that Adams and Le Verrier's research had pointed to. The planet itself was discovered on September 23, 1846 by the German astronomer Johann Gall.
Before the flyby of the Voyager 2 spacecraft in 1989, humanity had very little information about the planet Neptune. The mission provided data on Neptune's rings, number of moons, atmosphere and rotation. Voyager 2 also revealed significant features of Neptune's moon Triton. To date, the world's space agencies are not planning any missions to this planet.
Neptune's upper atmosphere is 80% hydrogen (H2), 19% helium and small amounts of methane. Like Uranus, Neptune's blue color is due to its atmospheric methane, which absorbs light at a wavelength that corresponds to the color red. However, unlike Uranus, Neptune has a deeper blue color, which indicates the presence of components in Neptune's atmosphere that are not present in Uranus's atmosphere.
Weather conditions on Neptune have two distinctive features. First, as was noticed during the flyby of the Voyager 2 mission, these are the so-called dark spots. These storms are comparable in scale to Jupiter's Great Red Spot, but differ greatly in their duration. The storm known as the Great Red Spot has been going on for centuries, but Neptune's dark spots can last no more than a few years. Information about this was confirmed thanks to observations from the Hubble Space Telescope, which was sent to the planet just four years after Voyager 2 made its flyby.
The second notable weather phenomenon on the planet is the rapidly moving white storms, which are called “Scooters”. As observations have shown, this is a unique type of storm system, the size of which is much smaller than the size of dark spots, and its lifespan is even shorter.
Like the atmospheres of other gas giants, Neptune's atmosphere is divided into latitudinal bands. The wind speed in some of these bands reaches almost 600 m/s, that is, the planet’s winds can be called the fastest in the solar system.
Structure of Neptune
Neptune's axial tilt is 28.3°, which is relatively close to Earth's 23.5°. Considering the planet’s significant distance from the Sun, Neptune’s presence of seasons comparable to those on Earth is a rather surprising and not fully understood phenomenon for scientists.
Moons and rings of Neptune
Today it is known that Neptune has thirteen satellites. Of these thirteen, only one is large and spherical in shape. There is a scientific theory according to which Triton, the largest of Neptune's moons, is a dwarf planet that was captured by a gravitational field and therefore its natural origin remains in question. Evidence for this theory comes from Triton's retrograde orbit - the moon rotates in the opposite direction to Neptune. Additionally, with a recorded surface temperature of -235°C, Triton is the coldest known object in the Solar System.
Neptune is believed to have three main rings: Adams, Le Verrier and Halle. This ring system is much fainter than those of other gas giants. The planet's ring system is so dim that for some time the rings were thought to be defective. However, images transmitted by Voyager 2 showed that this is in fact not the case and the rings completely encircle the planet.
It takes Neptune 164.8 Earth years to complete its orbit around the Sun. July 11, 2011 marked the completion of the planet's first full revolution since its discovery in 1846.
Neptune was discovered by Jean Joseph Le Verrier. The planet remained unknown to ancient civilizations due to the fact that it was not visible from Earth with the naked eye. The planet was originally named Le Verrier, in honor of its discoverer. But the scientific community quickly abandoned this name and the name Neptune was chosen.
The planet was named Neptune after the ancient Roman god of the sea.
Neptune has the second highest gravity in the solar system, second only to Jupiter.
Neptune's largest moon is called Triton, it was discovered 17 days after Neptune itself was discovered.
In Neptune's atmosphere you can see a storm similar to Jupiter's Great Red Spot. This storm has a volume comparable to that of the Earth and is also known as the Great Dark Spot.
Voyager 2 took this image of Neptune five days before its historic flyby of the planet on August 25, 1989.
The planet Neptune is a mysterious blue giant on the outskirts of the solar system, whose existence was not suspected until the end of the first half of the 19th century.
A distant planet, invisible without optical instruments, was discovered in the fall of 1846. J. C. Adams was the first to think about the existence of a celestial body that anomalously affects the movement. He presented his calculations and assumptions to the royal astronomer Erie, who ignored them. At the same time, the Frenchman Le Verrier was studying deviations in the orbit of Uranus; his conclusions about the existence of an unknown planet were presented in 1845. It was obvious that the results of the two independent studies were very similar.
In September 1846, an unknown planet was spotted through the telescope of the Berlin Observatory, located at the location indicated in Le Verrier's calculations. The discovery, made using mathematical calculations, shocked the scientific world and became the subject of a dispute between England and France about national priority. To avoid disputes, the German astronomer Halle, who examined the new planet through a telescope, can be considered the discoverer. According to tradition, the name of one of the Roman gods, the patron saint of the seas, Neptune, was chosen for the name.
Neptune's orbit
After Pluto from the list of planets, Neptune turned out to be the last - eighth - representative of the solar system. Its distance from the center is 4.5 billion km; it takes a wave of light 4 hours to travel this distance. The planet, along with Saturn, Uranus and Jupiter, entered the group of four gas giants. Due to the enormous diameter of the orbit, a year here is equal to 164.8 Earth years, and a day passes in less than 16 hours. The trajectory around the Sun is close to circular, its eccentricity is 0.0112.
Planet structure
Mathematical calculations made it possible to create a theoretical model of the structure of Neptune. In its center there is a solid core, similar in mass to the Earth; iron, silicates, and nickel are found in its composition. The surface looks like a viscous mass of ammonia, water and methane modifications of ice, which flows into the atmosphere without a clear boundary. The internal temperature of the core is quite high - reaching 7000 degrees - but due to the high pressure, the frozen surface does not melt. Neptune's is 17 times higher than Earth's and is 1.0243x10 in 26 kg.
Atmosphere and raging winds
The base is: hydrogen – 82%, helium – 15% and methane – 1%. This is a traditional composition for gas giants. The temperature on the conventional surface of Neptune shows -220 degrees Celsius. In the lower layers of the atmosphere, clouds formed by crystals of methane, hydrogen sulfide, ammonia or ammonium sulfide have been observed. It's these pieces of ice that create the blue glow around the planet, but that's only part of the explanation. There is a hypothesis about an unknown substance that gives a bright blue color.
The winds blowing on Neptune have a unique speed, its average is 1000 km/h, and hurricane gusts reach 2400 km/h. Air masses move against the planet's axis of rotation. An inexplicable fact is the increase in storms and winds, which is observed with increasing distance between the planet and the Sun.
The "" spacecraft and the Hubble telescope observed an amazing phenomenon - the Great Dark Spot - a hurricane of epic proportions that rushed across Neptune at a speed of 1000 km/h. Similar vortices appear and disappear in different places on the planet.
Magnetosphere
The giant's magnetic field has gained significant power; its basis is considered to be a conductive liquid mantle. A displacement of the magnetic axis relative to the geographic axis by 47 degrees causes the magnetosphere to change its shape following the rotation of the planet. This mighty shield reflects the energy of the solar wind.
Moons of Neptune
The satellite, Triton, was spotted a month after the grand discovery of Neptune. Its mass is equal to 99% of the entire satellite system. The appearance of Triton is associated with a possible capture from.
The Kuiper Belt is a vast region filled with objects the size of small satellites, but there are a few as large as Pluto and some perhaps even larger. Behind the Kuiper Belt is the place from which comets come to us. The Oort cloud extends almost halfway to the nearest star.
Triton is one of three moons in our system that has an atmosphere. Triton is the only one with a spherical shape. In total, in the company of Neptune there are 14 celestial bodies, named after the smaller gods of the sea depths.
Since the discovery of the planet, the presence of it has been discussed, but no confirmation of the theory has been found. It was only in 1984 that a bright arc was noticed at a Chilean observatory. The remaining five rings were found thanks to research by Voyager 2. The formations are dark in color and do not reflect sunlight. They owe their names to the people who discovered Neptune: Halle, Le Verrier, Argo, Lascelles, and the most distant and unusual one is named after Adams. This ring is made up of separate arms that should have merged into a single structure, but don't. A possible reason is considered to be the effect of gravity on undiscovered satellites. One formation remains nameless.
Research
Neptune's enormous distance from Earth and its special location in space make observing the planet difficult. The advent of large telescopes with powerful optics has expanded the capabilities of scientists. All studies of Neptune are based on data obtained by the Voyager 2 mission. The distant blue planet, flying at the edge of the world we know, is full of things about which we still know practically nothing.
New Horizons captures Neptune and its moon Triton. The image was taken on July 10, 2014 from a distance of 3.96 billion kilometers.
Images of Neptune
Voyager 2's images of Neptune and its moons are largely underappreciated. More fascinating than even Neptune itself is its giant moon Triton, which is similar in size and density to Pluto. Triton may have been captured by Neptune, as evidenced by its retrograde (clockwise) orbit around Neptune. The gravitational interaction between the satellite and the planet generates heat and keeps Triton active. Its surface has several craters and is geologically active.
Its rings are thin and weak and almost invisible from Earth. Voyager 2 took the photo while they were backlit by the Sun. The image is severely overexposed (10 minutes).
Neptune clouds
Despite its great distance from the Sun, Neptune has highly dynamic weather, including the strongest winds in the Solar System. The "Great Dark Spot" seen in the image has already disappeared and shows us how quickly changes are happening on the most distant planet.
The most complete map of Triton to date
Paul Schenk from the Lunar and Planetary Institute (Houston, USA) reworked old Voyager data to reveal more details. The result is a map of both hemispheres, although most of the Northern Hemisphere is missing because it was in shadow when the probe passed.
Animation of the Voyager 2 spacecraft flying past Triton a, committed in 1989. During the flyby, most of the Northern Hemisphere Triton but was in the shadows. Due to Voyager's high speed and slow rotation Triton oh, we could only see one hemisphere.
Geysers of Triton
Characteristics of the planet:
- Distance from the Sun: 4,496.6 million km
- Planet diameter: 49,528 km*
- Day on the planet: 16h 06min**
- Year on the planet: 164.8 years***
- t° on the surface: °C
- Atmosphere: Composed of hydrogen, helium and methane
- Satellites: 14
* diameter along the planet's equator
**period of rotation around its own axis (in Earth days)
***period of orbit around the Sun (in Earth days)
Neptune is the last of the four gas giants belonging to the solar system. It is in eighth place in terms of distance from the sun. Because of its blue color, the planet got its name in honor of the ancient Roman ruler of the ocean - Neptune. The planet has 14 currently known satellites and 6 rings.
Presentation: planet Neptune
Planet structure
The huge distance to Neptune does not allow us to accurately establish its internal structure. Mathematical calculations have established that its diameter is 49,600 km, it is 4 times the diameter of the Earth, 58 times in volume, but due to its low density (1.6 g/cm3) its mass is only 17 times that of the Earth.
Neptune is composed mostly of ice and belongs to the group of ice giants. According to calculations, the center of the planet is a solid core, which is 1.5-2 times larger in diameter than the Earth’s. The basis of the planet is a layer of methane, water and ammonia ice. The base temperature ranges from 2500-5500 degrees Celsius. Despite such a high temperature, the ice remains in a solid state, this is due to the high pressure in the bowels of the planet, it is millions of times higher than on Earth. The molecules are pressed so tightly together that they are crushed and broken into ions and electrons.
Atmosphere of the planet
The atmosphere of Neptune is the outer gaseous shell of the planet, its thickness is approximately 5000 kilometers, its main composition is hydrogen and helium. There is no clearly defined boundary between the atmosphere and the ice layer; the density gradually increases under the mass of the upper layers. Closer to the surface, gases under pressure turn into crystals, which become more and more numerous, and then these crystals are completely transformed into an ice crust. The depth of the transition layer is approximately 3000 km
Moons of the planet Neptune
Neptune's first satellite was discovered in 1846 by William Lassell almost simultaneously with the planet and was named Triton. In the future, the Voyager 2 spacecraft studied this satellite well, receiving interesting images in which canyons and rocks, lakes of ice and ammonia, as well as unusual volcanoes-geysers are clearly visible. The Triton satellite differs from others in that it also has a reverse motion in the direction of its orbit. This leads scientists to speculate that Triton was not previously related to Neptune and was formed outside the influence of the planet, perhaps in the Kuiper strip, and then was “captured” by Neptune’s gravity. Another satellite of Neptune, Nereid, was discovered much later in 1949, and during the space mission to the Voyager 2 apparatus, several small satellites of the planet were discovered at once. The same device also discovered a whole system of dimly lit rings of Neptune. At the moment, the last of the discovered satellites is Psamapha in 2003, and the planet has a total of 14 known satellites.
Although, of course, the word “giant” will be a little strong in relation to Neptune, a planet that, although very large by cosmic standards, is, nevertheless, significantly inferior in size to our other giant planets: Saturn, Saturn, etc. Speaking of Uranus, although this planet is larger in size than Neptune, Neptune is still 18% larger in mass than Uranus. In general, this planet, named because of its blue color in honor of the ancient god of the seas, Neptune can be considered the smallest of the giant planets and at the same time the most massive - Neptune’s density is many times stronger than that of other planets. But compared to Neptune and our Earth, they are tiny, if you imagine that our Sun is the size of a door, then the Earth is the size of a coin, and Neptune is the same in size as a large baseball.
The history of the discovery of the planet Neptune
The history of the discovery of Neptune is unique in its kind, since it is the first planet in our solar system that was discovered purely theoretically, thanks to mathematical calculations, and only then was it noticed through a telescope. It happened like this: back in 1846, French astronomer Alexis Bouvard observed the movement of the planet Uranus through a telescope and noticed strange deviations in its orbit. The anomaly in the movement of the planet, in his opinion, could be caused by the strong gravitational influence of some other large celestial body. Alexis’s German colleague, astronomer Johann Halle, made the necessary mathematical calculations to determine the location of this previously unknown planet, and they turned out to be correct - soon our Neptune was discovered at the site of the supposed location of the unknown “Planet X”.
Although long before this, the planet Neptune was observed in a telescope by the great. True, in his astronomical notes he noted it as a star, not a planet, so the discovery was not credited to him.
Neptune is the most distant planet in the solar system
“But what about?”, you probably ask. In fact, everything here is not as simple as it seems at first glance. Since its discovery in 1846, Neptune has rightfully been considered the farthest planet from the Sun. But in 1930, little Pluto was discovered, which is even further away. There’s just one nuance here: Pluto’s orbit is strongly elongated along an ellipse in such a way that at certain moments of its movement Pluto is closer to the Sun than Neptune. The last time such an astronomical phenomenon occurred was from 1978 to 1999 - for 20 years, Neptune again had the title of the full-fledged “farthest planet from the Sun.”
Some astronomers, in order to get rid of these confusions, even proposed to “demote” Pluto from the title of planet, they say, it is just a small celestial body flying in orbit, or to assign the status of a “dwarf planet”, however, disputes on this matter are still ongoing.
Features of the planet Neptune
Neptune has its bright blue appearance due to the strong density of clouds in the planet’s atmosphere; these clouds conceal chemical compounds that are still completely unknown to our science, which, when absorbed from sunlight, turn blue. One year on Neptune is equal to our 165 years, which is the time it takes Neptune to complete its full cycle in its orbit around the Sun. But a day on Neptune is not as long as a year; it is even shorter than ours on Earth, since it lasts only 16 hours.
Neptune temperature
Since the sun’s rays reach the distant “blue giant” in very small quantities, it is natural that it is very, very cold on its surface - the average surface temperature there is -221 degrees Celsius, which is two times lower than the freezing point of water. In a word, if you were on Neptune, you would turn into ice in the blink of an eye.
Surface of Neptune
Neptune's surface consists of ammonia and methane ice, but the planet's core may well turn out to be rock, but this is still just a hypothesis. It is curious that the force of gravity on Neptune is very similar to that of Earth, it is only 17% greater than ours, and this despite the fact that Neptune is 17 times larger than Earth. Despite this, we are unlikely to be able to walk around Neptune in the near future, see the previous paragraph about the ice. And besides, strong winds blow on the surface of Neptune, the speed of which can reach up to 2400 kilometers per hour (!), perhaps on no other planet in our solar system there are such strong winds as here.
Neptune size
As mentioned above, it is 17 times larger than our Earth. The picture below shows a comparison of the sizes of our planets.
Atmosphere of Neptune
The composition of Neptune's atmosphere is similar to the atmospheres of most similar giant planets: it is mainly dominated by hydrogen and helium atoms, and also contains small amounts of ammonia, frozen water, methane and other chemical elements. But unlike other large planets, Neptune’s atmosphere contains a lot of ice, which is due to its remote position.
Rings of the planet Neptune
Surely when you hear about planetary rings, Saturn immediately comes to mind, but in fact, it is far from the only owner of rings. Our Neptune also has rings, although not as large and beautiful as those of the planet. Neptune has five rings in total, named after the astronomers who discovered them: Halle, Le Verrier, Lascelles, Arago and Adams.
Neptune's rings consist of small pebbles and cosmic dust (many micron-sized particles), their structure is somewhat similar to the rings of Jupiter and they are quite difficult to notice, since they are black. Scientists believe that Neptune's rings are relatively young, at least much younger than the rings of its neighbor Uranus.
Moons of Neptune
Neptune, like any decent giant planet, has its own satellites, not just one, but thirteen, named after the smaller sea gods of the ancient pantheon.
Particularly interesting is the satellite Triton, discovered, in part, thanks to... beer. The fact is that the English astronomer William Lasing, who actually discovered Triton, made a large fortune by brewing and trading beer, which subsequently allowed him to invest a lot of money and time in his favorite hobby - astronomy (especially since equipping a high-quality observatory is not cheap).
But what is interesting and unique about Triton? The fact is that this is the only known satellite in our solar system that rotates around the planet in the opposite direction relative to the rotation of the planet itself. In scientific terminology, this is called “retrograde orbit.” Scientists suggest that Triton was not previously a satellite at all, but an independent dwarf planet (like Pluto), which, by the will of fate, fell into the sphere of influence of Neptune’s gravity, essentially captured by the “blue giant.” But it doesn't end there: Neptune's gravity pulls Triton closer and closer, and after several million light years, gravitational forces can tear the satellite apart.
How long does it take to fly to Neptune?
For a long time. This is in short, with modern technology, of course. After all, the distance from Neptune to the Sun is 4.5 billion kilometers, and the distance from Earth to Neptune is 4.3 billion kilometers, respectively. The only satellite sent from Earth to Neptune, Voyager 2, launched in 1977, reached its destination only in 1989, where it photographed the “large dark spot” on the surface of Neptune and observed a number of powerful storms in the planet’s atmosphere.
Planet Neptune video
And at the end of our article, we offer you an interesting video about the planet Neptune.
And there is no evidence that Galileo perceived the noticed Neptune as a new, previously unknown luminary.
In 1847, after the discovery of Neptune and calculation of the characteristics of its orbit, the American astronomer S. Walker from the US Naval Observatory, examining archival records, discovered that on May 8 and 10, 1795, the French astronomer Lalande from the Paris Observatory observed a star located in the same the place where Neptune was supposed to be. The discovery of these records of Neptune's position in 1795 contributed to a more accurate calculation of the planet's orbit.
Perturbations of the orbit of Uranus and their interpretation
Soon after 1831-1832, several hypotheses were put forward in the scientific community to explain the incomprehensible "behavior" of Uranus.
1. In its movement, Uranus experiences resistance from the gas-dust environment that fills interplanetary space. This resistance causes systematic deviations from the calculated trajectory, constructed without taking into account any resistance of the environment.
2. Uranus has a satellite that has not yet been discovered, which causes the observed deviations.
3. Shortly before the discovery of Uranus by Herschel, a collision of this planet occurred or its approach to a comet, which sharply changed the orbit of Uranus.
4. Newton's law of attraction does not remain absolutely valid at such large distances from the Sun as Uranus is located and beyond.
5. The movement of Uranus is influenced by another, still undiscovered and unknown planet (see figure).
Options 1-3 were rejected by the astronomical community almost immediately; with regard to option 4, most astronomers experienced serious skepticism. Thus, hypothesis No. 5 remained the most probable.
In a number of sources, the first person to suggest the existence of a post-uranium planet is the English astronomer Thomas Hussey. After the publication of tables of the motion of Uranus by the French astronomer A. Bouvard, Hussey, based on his own observations, discovered anomalies in the orbit of Uranus and suggested that they could be caused by the presence of an outer planet. After this, Hussey visited Bouvard in Paris and discussed with him the issue of these anomalies. Bouvard promised Hussey to carry out the calculations necessary to find a hypothetical planet if he could find the time to do so. In November, Hussey sent a letter to D. B. Airey (who became director of the Greenwich Observatory in 1835), noting:
“I had a conversation with Alexis Bouvard about a subject on which I have often reflected and which will probably interest you; your opinion will determine mine. Having been doing a lot of observations of Uranus in the last year, I became closely acquainted with Bouvard's tables for this planet. The seemingly inexplicable contradictions between the “old” and “new” observations suggested to me the possibility of the existence of some disturbing body beyond the orbit of Uranus, which remains unknown and therefore has not been taken into account until now. My first idea was to establish empirically some approximate position in the sky of this supposed body, and then set to work with my large reflector, scanning all the small stars around. But I myself found myself completely unable to carry out the first part of such a program... Later, in a conversation with Bouvard, I asked him if this could happen. His answer was in the affirmative... and that he corresponded with Hansen on this matter... To my question whether it was possible to obtain the provisions empirically and then organize searches in the immediate vicinity, he gave a completely positive answer. He said at the same time that the calculations required for this were not so much difficult as they were cumbersome, and that if he had free time, he would have undertaken them and passed on the results to me as a basis for conducting observations in precisely the required small area of the sky.”
Airy responded:
“I've been thinking a lot about the irregularities of Uranus... It's a mystery. But I do not hesitate to express the opinion that now there is not the slightest hope of finding out the nature of the external influence. If there is such a thing, then I very much doubt the possibility of determining the position of the planet that has this effect. I am sure that this cannot be done until the nature of the irregularities is well determined after several successive revolutions of Uranus [around the Sun]."
Since Uranus has an orbital duration of 84 years, Airy's letter dampened Hussey's enthusiasm for the search for a post-uranian planet.
But, despite Airy’s skepticism, by 1836 the world astronomical community had an idea that there was a fairly massive planet beyond the orbit of Uranus and that it should be looked for. This was the opinion expressed, for example, in 1835 by the famous German astronomer E. B. Waltz and the director of the observatory in Palermo N. Cacciatore. The latter even reported that in May 1835 he observed a moving celestial body, apparently representing a planet located beyond the orbit of Uranus.
The French astronomer Louis Wartmann, having learned about Cacciatore's observations, published a note in the same 1836, in which he says that back in September 1831 he also observed a moving celestial body and speaks out in favor of the fact that this is a new planet that should be located approximately twice the distance from the Sun compared to Uranus, and its period of revolution should therefore be about 243 years.
It remains unknown whether Wartman and Cacciatore actually observed a new planet, but, in any case, their words speak not only of the prevalence of the hypothesis about the existence of an unknown planet, but also of the fact that the question of the location of this planet has already been raised - beyond the orbit of Uranus. But accurate calculations of the characteristics of this planet and its orbit were not made until the mid-1840s.
Opening at the tip of the pen
Calculations by D. C. Adams
Throughout the winter of 1845 and the spring of 1846, Le Verrier intensively continued his research and on June 1 submitted a second article on this problem to the Academy of Sciences. It consists of two parts. In the first part, Le Verrier re-compares all existing observations of Uranus and calculations according to his exact theory of the motion of Uranus. Much more detailed and more accurate data on discrepancies between theory and observations than Adams's was obtained. 115 conditional equations based on 279 observations from 1690 to 1845 are considered in order to eliminate these discrepancies by correcting the elements of the original orbit of Uranus. Le Verrier draws a categorical conclusion: the observations are completely irreconcilable with the theory, and turns to Airy in a letter dated June 28, 1846 with a request to organize a search for a new planet:
“If I can hope that you trust my work enough to begin searching for a planet in the sky, then I will hasten to send you its exact coordinates as soon as I have calculated them.”
To this Airy responded negatively: “The imminent departure to Europe does not allow me to disturb Monsieur Le Verrier with a request for more accurate numbers.” However, Airy's departure to Europe was planned only after a month and a half. Airy himself, in a conversation with Challis and John Herschel on June 29, raised the question of organizing a search for a new planet. Since he had complete confidence in Le Verrier's work, the reasons for Airy's response remain unclear.
The search for a new planet began in England on July 29, 1846. Le Verrier knew nothing about them until the very end.
Le Verrier continues to work actively and on August 31, 1846, presents his third article to the Paris Academy of Sciences entitled: “On the planet that produces the anomalies observed in the movement of Uranus. Determination of its mass, its orbit and its present position." But in France, despite the enormous success of Le Verrier’s work, none of the astronomers was going to start searching for a new planet. Then Le Verrier turns for help to the German astronomer Johann Halle, a 34-year-old assistant at the Berlin Observatory. There was a convenient reason for this: a year ago, Halle sent Le Verrier, as a sign of respect, his dissertation devoted to the analysis of observations of the movement of Uranus made by the Danish astronomer Ole Roemer. And on September 18, Le Verrier sends a letter to Halle, in which he writes: “Right now I would like to find a persistent observer who would agree to devote some time to observations in that area of \u200b\u200bthe sky where an unknown planet may be located. I came to my conclusion based on the theory of the movement of Uranus... The position of the planet now and over the next few months is favorable from the point of view of its detection. The mass of the planet allows us to conclude that its visible disk is more than 3". When observed through a good telescope, this disk can be quite distinguished from the twinkling images of stars."
Discovery of a new planet
Johann Gottfried Halle
Henry Louis d'Arre
I. Galle, having received Le Verrier’s letter on September 23, began observations that evening. Since the search for a new planet was not part of the scheduled observations of the Berlin Observatory, unscheduled work had to be obtained permission from the director of the observatory I. F. Encke, who was distinguished by great pedantry in observing observation regulations, as well as a fair amount of skepticism regarding the initiatives of young employees. At first, Enke refused Halle, but after persistent requests from the latter he agreed, since he was leaving to celebrate his anniversary (Enke turned 55 on September 23, 1846). 24-year-old student Heinrich d'Arre enthusiastically volunteered to help Halle in the search for a new planet.
For observations, an achromatic refractor with a 24-centimeter mirror manufactured by I. Fraunhofer was used. (This telescope was subsequently housed in the Deutsches Museum in Munich, where it can currently be seen as an exhibit). There were two possible ways to find a new planet:
- 1. By apparent movement relative to the stars (in this case, each star in the area where the new planet was supposed to be located had to be observed twice at intervals of several days, recording its exact coordinates);
- 2. According to the visible disk (the size of which, as Le Verrier indicated, should have been about 3").
New Berlin Observatory on Unter der Linden, where Galle and d'Arre made observations
At first, Galle, pointing the telescope at the point in the sky indicated by Le Verrier, did not discover a new planet. Then d’Arre proposed a third search method: use a star map, comparing the luminaries shown on the map with those that are actually observed in the sky. Since an unknown planet cannot be on the map, it will be a star that is not indicated on the star map. This required a fairly detailed and accurate star map, and the Berlin Observatory had such a map. This was a map of the star atlas of the Berlin Academy of Sciences, compiled by Karl Bremiker and printed at the end of 1845. (By September 1846, this map had not yet been distributed to the observatories of Great Britain and France).
Taking Bremiker's map, Galle and d'Arre continued their observations. Galle named the stars, their position and brightness, in turn, and d’Arre marked them on the map. Immediately after midnight (at 0 hours 0 minutes 14 seconds on September 24), Galle named a star of approximately 8th magnitude, which d’Arré did not find on the map. Its position differed from that indicated by Le Verrier by 52." With this news, despite the late hour, d'Arre ran to Encke, who joined the observations of his young colleagues, and the three of them observed the discovered object until its sunset at 2:30 a.m. Final They were not sure that the observed star was a new planet, since due to the weakness of the selected telescope eyepiece, they were unable to see the disk of the star. It was decided to continue observations the next night. Observations were carried out on the evening of September 24 using a telescope with an eyepiece. giving a 320-fold magnification, and that evening all three observers were able, firstly, to discern a disk approximately 3" in size near the new star, and secondly, to detect its apparent proper movement - approximately 70" to the west, which completely coincided with Le Verrier's estimates After this, there was no doubt: a new planet in the solar system had been discovered. Galle notified Le Verrier of this discovery in a letter dated September 25.
Choosing a name for a new planet
Halle, in his letter to Le Verrier on September 25, proposed the name "Janus" for the new planet. This was in accordance with the tradition accepted among astronomers, when the name of a new object was given by its discoverer. However, in this case the situation was different: the world scientific community regarded the discovery of a new planet as the exceptional merit of Le Verrier.
Le Verrier, in letters to Halle and the editor of the main German astronomical journal Astronomische Nachrichten, G. H. Schumacher, proposes his name - “Neptune”. On October 1, he writes letters to D. B. Airy and the director of the Pulkovo Observatory V. Ya. Struve with a proposal to name the new planet Neptune. But in early October, Le Verrier suddenly changes his mind and proposes to name the planet in his honor - “Le Verrier.” In this he was actively supported by the director of the Paris Observatory, François Arago, but this initiative encountered significant resistance outside France. French almanacs very quickly returned the name "Herschel" for Uranus, in honor of its discoverer William Herschel, and "Leverrier" for the new planet.
In England, Challis suggested another name: "Ocean".
Myths about the discovery of Neptune
The discovery of Neptune, like any significant event in history, began to become overgrown with myths. One of them is the time and circumstances of the discovery of the planet allegedly predicted by Nostradamus 300 years in advance. In the 4th century, 33rd quatrain of Nostradamus there are the lines:
Jupiter is associated with Venus more than with the Moon,
Appearing in all its splendor.
Venus is hidden, Neptune has disappeared in the light of the Moon,
Struck by the heavy spear of Mars.
Some interpreters of Nostradamus have proposed the following interpretation of these lines:
Neptune in the light of the full moon.
Full moon. Constellation 08/07/1846.
Mars in opposition to Neptune.
Venus below the horizon.
Distance from Venus to Jupiter.
Distance from Jupiter to the Moon.
Critics of Nostradamus note that each phrase of his quatrains can be interpreted in dozens of different ways, “tailoring” the interpretation to the events that actually occurred. All interpretations of Nostradamus’ texts are the imposition of “predictions” on past events in order to prove their truth. Indeed, so far no one has been able to publicly predict a single event in the future using so-called “prophecies,” and the quatrain supposedly dedicated to the discovery of Neptune is no exception.
Worldview significance of the discovery of Neptune
The discovery of Neptune was of exceptional importance for science, since it finally confirmed the validity of both
