History of discovery of each planet in our Solar system

Satellites like “Kepler” worked overtime to open hundreds of new planets in our galaxy. But how do we first discover the planets in our local volume of space? That is, in our bubble called the Solar system. Here all the stories of how astronomers living hundreds of years ago discovered each planet in our Solar system.



Being the nearest planet to the Sun in our Solar system, mercury revolves within 46-70 million kilometers from the sun. Ancient astronomers knew about the speed of planet rotation around the sun: Assyrian astronomers associated the planet with gods such as NABU, the scribe and messenger of the gods, the ancient Greeks called it the body of mercury, in honor of the messenger of the gods. What is this Association? Year on this planet lasts only 88 days, the shortest of all.

In 1631, the astronomer Pierre Gassendi first observed the transit of mercury across the sun, and just a few years later another astronomer Giovanni Zupi opened phase, indicating that the planet revolves around the Sun. Other astronomers were gradually added to these discoveries: Italian astronomer Giovanni Schiaparelli observed the planet and concluded that mercury was tidal locked with the sun that is facing the sun is always only on one side.

In the modern age of space exploration came other discoveries: much of the planet was discovered only recently. Soviet scientists first to use radar to study the planet in the early 1960s, scientists at the Arecibo Observatory with the radio telescope discovered that the planet rotates once in 59 days, not 88, as previously thought. In 1974 the probe Mariner 10 visited the planet, made several overflights, mapping the surface, and in 2008 arrived to the planet the probe MESSENGER in orbit which remains to this day.



The second planet in the Solar system, Venus is the brightest of the planets observed from Earth. For this reason, it was studied from time immemorial: the first record of it appeared the Babylonians called the planet Ishtar. The Romans saw Venus the goddess of beauty, and the Maya believed that the planet is a brother of the sun. In 1610 Galileo Galilei observed the phases of Venus, confirming that the planet revolves around the Sun. Because of the dense atmosphere of the planet surface observation was impossible before the 1960-ies, however, many believed that Venus has life, because the size of the planet was similar to Earth.

In 1958, radar imagery found that the planet’s surface unbearably hot — and therefore inhospitable to life. Mankind decided to look at the evil sister of the Earth closer. The first attempt, the Soviet probe Venera-1 was launched, in 1961 and did not succeed, but Mariner 2, launched by the US, succeeded, having flown around the planet and confirming its temperature, and the absence of magnetic field. A new Soviet mission Venera-4 successfully reached Venus and sent back information about the planet’s atmosphere before burning to the ground during reentry. For these missions was followed by several others: Mariner 5, Venera 5 and 6, “Venera-7” on a successful landing, and after a repetition of the success forces “Venus-8”. These last two probe became the first artificial object that landed successfully on the surface of another planet. Both were destroyed by the pressure and heat of the planet, but the Soviet Union continued to send probes. NASA, too: “pioneer-12” revolved around the planet for 14 years, mapping the surface, and “pioneer 13 sent a few probes straight to her.



The earth is continuously observed by mankind since its appearance. But although we knew we’re on solid ground to find out the true nature of our house, had to wait a bit. For many centuries people believed that the Earth is not the same object as observed above it all revolved around the Earth. Already in the times of Aristotle philosophers determined that the Earth is spherical in shape, watching the shadow of the moon.

Mikolaj Kopernik — known as Nicholas — postulated the heliocentric view of the Solar system in 1514. The book “About rotation of heavenly spheres” was first published in 1543 and called into question the generally accepted point of view. The theory was controversial, but it was followed by the three volume work of Johannes Kepler on the subject of Copernican astronomy. Kepler developed three laws of planetary motion: Planets move around the Sun in an ellipse, with the Sun in one of the magic”, “Every planet moves in the plane passing through the center of the Sun, and for equal time intervals the radius vector connecting the Sun and the planet describes equal areas”, “the Squares of the periods of revolution of planets around the Sun are as the cubes of semi-major axes of the orbits of the planets.” These laws helped to define the movement of the planets and allowed us to question the previous view of the Solar system. At first, Kepler’s theory was not popular, but eventually dispersed across Europe. By the time when Copernicus published his views, the expedition of Ferdinand Magellan was able to circumnavigate the globe in 1519.

24 October 1946, we were able to see our home world, when first the Earth was made with a modified rocket “FAU-2”, launched from the landfill in new Mexico.



Blood-red fourth planet in our Solar system has long been associated with the Roman God of war named Mars. And if many believed that Venus could have the earth’s atmosphere, similar thoughts were on the topic of Mars. In 1877, exploring the planet with a telescope, the astronomer Giovanni Schiaparelli described a number of features which he called Canali. This word was translated incorrectly, and Mars suddenly discovered channels, and, as thinking people, are artificial. Twenty years later, another astronomer, Camille Flammarion also identified surface features of artificial origin, and people finally believed that the planet might be life. Public perception has led to the emergence of a number of science fiction novels on the subject of Mars, such as the “War of the worlds” by Hg wells.

Advances in telescopes that came later, allowed to look at the planet in new ways. Astronomers were able to measure the temperature of the planet, determine its atmospheric content and weight. During the 1960-ies, the Soviet Union tried to send eight probes to Mars, but never reached the success, although in the 1970-ies to Mars successfully arrived the orbiters. NASA tried to send to Mars 3 Mariner, but Mariner 4, launched in 1964, successfully flew around the planet and showed that she was dead. And yet, after these reconnaissance missions “Viking” became the first invasion: July 20, 1976, the probe landed on the Red planet for an unprecedented mission that lasted until 1982. Soon followed by Viking 2″ landed on Mars in September 1976 and worked until 1980.

Despite the success of the mission, only in 1997, Mars was unloaded first mobile Rover mission Mars Pathfinder. The ensuing mission of the Mars Climate Orbiter failed due to human error, and several Martian probes just flew. In 2004, NASA launched the Mars Rovers Spirit and opportunity, which was not an example of success. In 2012 at the same time a Rovers arrived “Curiosity”, which still works.



The largest planet of our Solar system, Jupiter, observed from the most ancient times. She helped lead the Chinese 12-year cycle, and it was named after the king of Roman gods. She was also a goal of many astronomers. Galileo first observed the four main moons of Jupiter, now known as the Galilean moons: IO, Europa, Ganymede and Callisto, named after the lovers of Zeus. Astronomer Robert Hooke discovered a large system of storms on the gas giant, and in 1665 it was confirmed by Giovanni Cassini in parallel for the first time noticing the Great Red Spot, which was formally discovered in 1831. Not having a solid ground, storms rage on Jupiter. Astronomers Giovanni Borelli and Cassini, using orbital tables and mathematics, discovered something strange: being in opposition to Earth, Jupiter seventeen minutes late relative to the calculations that says that the light is not an instant phenomenon, and has a delay.

In 1900-ies led to other discoveries: using a radio telescope to study the crab nebula from 1954 to 1955, the astronomer Bernard Burke found interference from one part of the sky and in the end found out that Jupiter radiates the waves with the radiation of the planet. In 1973, the mission of the “Pioneer” became the first probes, which flew past the planet and made a number of close shots. In 1977 the Ground was running two missions the probes Voyager-1 and Voyager-2″, designed to study the outer planets of the Solar system. The first of them reached Jupiter two years later: Voyager 1 arrived in March 1979, “Voyager 2” in July 1979. Both found a lot of useful information about the planet and its satellites, before going further, found a small system of rings and additional satellites. In 1992, the Jupiter mission arrived “Ulysses” in 1995 on the orbit of the planet came out the probe “Galileo”, “Cassini” flew in 2000 and New horizons in 2007. In 1994, scientists have also observed something incredible: in the southern horizon of Jupiter crashed into a planet shoemaker-levy, leaving a huge scar in the planet’s atmosphere. Currently, attempts are being made to study the moons of Jupiter, some of which can be great candidates for life.



The sixth planet from the Sun, perhaps the most interesting is the last of the classically recognized planet: the Romans named it after their God of agriculture. Only in 1610, Galileo drew attention to the most striking feature of the planet. By studying its properties, he decided that he stumbled across a few orbital satellites. But in 1655 Christian Huygens, armed with a more powerful telescope, found that this feature represents a ring surrounding the planet. Soon after, he found the first satellite of Saturn, Titan. In 1671, Giovanni Cassini found four more of the moon: yapet, ray, Tethys and dione in the gaps between the rings of the planet, and then it dawned on me: these rings consisted of particles smaller. In 1789, a German astronomer, William Herschel noted another two moons: Mimas and Enceladus, and over the next hundred years, were found two more satellites: Hyperion in 1848, and Phoebe in 1899.

When NASA began to explore the outer planets, Saturn was first visited by the probe “pioneer 11 in September 1979, after a few shots. Probes the twin Voyager arrived next, in 1980 and 1981, providing us high-resolution imagery. The planet has become the intersection for pairs of probes: Voyager 1 used Saturn to disperse and departure from the Solar system, and Voyager 2 went to Uranus. In 2004 alone, the planet got the next visitor in the form of the mission Cassini, which is still studying the planet and its satellites.



The seventh planet, Uranus, was hard to find without the aid of telescopes so that its history is not as long as other planets. Watching the skies in December 1690, astronomer John Flamsteed was the first to discover the planet, but decided that the star 34 Tauri. And only 31 March 1781 Herschel was the first to decide that this star is actually a comet. Further examination of this “comet” has led to the fact that it was a planet. Herschel called it Georgium Sidus in honor of king George the Third, but in the end, the planet was named Uranium in honor of Chronos. The discovery was unprecedented: he had found the most distant object in the Solar system. In the 19th century, astronomers noticed something strange about the orbit of this object: he did not answer mathematical theories and deviate from its course. Obviously, it was influenced by something else further into the Solar system.

But the most unusual feature of the planet was its orientation: instead of rotating like the other planets in the system, Uranus is lying and rotating on its side. The reason for this is unknown, as the theory put forward by the planetary collision. In 2009, the members of the Paris Observatory, suggested that when the planet was in its infancy, in the planetary disk formed the moon, which rocked the planet. In 1986, the probe Voyager 2″ passed by Uranus, studying the planet’s atmosphere and opening a number of additional satellites and ring system. He became the first and only probe to reach that planet, is not currently scheduled any future missions.



The last “official” planet in our Solar system is Neptune. Revolving 30. that is from the Sun, he became the first planet that was discovered using mathematical calculations, not direct observations. Studying Uranus, astronomers discovered that the planet does not meet their predictions, and attempted to resolve this issue. At that time it was already known that the orbit of the planets influenced by the other major bodies in the Solar system, but even with all this, the Uranium violated expectations. In 1835 Halley’s comet reached perihelion slightly later than expected, which led astronomers to think that there is another object in the system, which has an impact on the Uranium.

Astronomers began to search further to explain the motion of planets. In England and France had their own astronomers, who first stumbled on the trail: John Coach Adams and Le Verrier Urbarn. From 1843 to 1845 Adams has done the right calculations, but was rejected by the Royal astronomical society. Verrier came to such a decision and appealed to Johann Gottfried Galle, who, following Le Verrier’s instructions, discovered a new planet where it was predicted, on 23 September 1846. Next month, the English astronomer discovered the satellite of Neptune Triton. The solar system has increased in size two times together with the opening.

Neptune was visited by the probe “Voyager-2” on 25 August 1989, where he took the readings of the planet and went on to study Triton, near which we found a moon Nereid. At the same time, it was discovered that the planet was very warm, much warmer than expected and has a turbulent atmosphere with a Large Dark Spot similar to Jupiter’s Great Red Spot. Visit Neptune, Voyager 2 left the Solar system and went into deep space.

The history of the discovery of the Solar system, its planets, this is an interesting way to look at the history of science and understanding of the humanity of our close neighbours. The study of our planets has changed our view of the world around us and understanding our place in the Universe.

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