A hypothetical stream bed following a tilted valley. The maximum gradient is along the down-valley axis represented by a hypothetical straight channel. Meanders develop, which lengthen the course of the stream, decreasing the gradient.

Meanders of the Rio Cauto at Guamo Embarcadero, Cuba.

A meander, in general, is a bend in a sinuous watercourse or river. A meander is formed when the moving water in a stream erodes the outer banks and widens its valley. A stream of any volume may assume a meandering course, alternately eroding sediments from the outside of a bend and depositing them on the inside. The result is a snaking pattern as the stream meanders back and forth across its down-valley axis. When a meander gets cut off from the main stream, an oxbow lake is formed. Over time meanders migrate downstream, sometimes in such a short time as to create civil engineering problems for local municipalities attempting to maintain stable roads and bridges.

There is not yet full consistency or standardization of scientific terminology used to describe watercourses. A variety of symbols and schemes exist. Parameters based on mathematical formulae or numerical data vary as well, depending on the database used by the theorist. Unless otherwise defined in a specific scheme "meandering" and "sinuosity" here are synonymous and mean any repetitious pattern of bends, or waveforms. In some schemes, "meandering" applies only to rivers with exaggerated circular loops or secondary meanders; that is, meanders on meanders.

Sinuosity is one of the channel types that a stream may assume over all or part of its course. All streams are sinuous at some time in their geologic history over some part of their length.

Origin of term[link]

The term derives from a river located in present-day Turkey and known to the Greeks as (Μαίανδρος) Maiandros or Maeander, characterised by a very convoluted path along the lower reach. As such, even in Classical Greece (and in later Greek thought) the name of the river had become a common noun meaning anything convoluted and winding, such as decorative patterns or speech and ideas, as well as the geomorphological feature. Strabo said: "... its course is so exceedingly winding that everything winding is called meandering."^[1]

The Meander River is located south of Izmir, east of the ancient Greek town of Miletus, now, Milet, Turkey. It flows through a graben in the Menderes Massif, but has a flood plain much wider than the meander zone in its lower reach. In the Turkish name, the Büyük Menderes River, Menderes is from "Meander".

Meander geometry[link]

Uvac canyon meander, Serbia

The technical description of a meandering watercourse is termed meander geometry or meander planform geometry.^[2] It is characterized as an irregular waveform. Ideal waveforms, such as a sine wave, are one line thick, but in the case of a stream the width must be taken into consideration. The bankfull width is the distance across the bed at an average cross-section at the full-stream level, typically estimated by the line of lowest vegetation.

As a waveform the meandering stream follows the down-valley axis, a straight line fitted to the curve such that the sum of all the amplitudes measured from it is zero. This axis represents the overall direction of the stream.

At any cross-section the flow is following the sinuous axis, the centerline of the bed. Two consecutive crossing points of sinuous and down-valley axes define a meander loop. The meander is two consecutive loops pointing in opposite transverse directions. The distance of one meander along the down-valley axis is the meander length or wavelength. The maximum distance from the down-valley axis to the sinuous axis of a loop is the meander width or amplitude. The course at that point is the apex.

In contrast to sine waves, the loops of a meandering stream are more nearly circular. The curvature varies from a maximum at the apex to zero at a crossing point (straight line), also called an inflection, because the curvature changes direction in that vicinity. The radius of the loop is considered to be the straight line perpendicular to the down-valley axis intersecting the sinuous axis at the apex. As the loop is not ideal, additional information is needed to characterize it. The orientation angle is the angle between sinuous axis and down-valley axis at any point on the sinuous axis.

Concave bank and convex bank, Great Ouse Relief Channel, England.

A loop at the apex has an outer or convex bank and an inner or concave bank. The meander belt is defined by an average meander width measured from outer bank to outer bank instead of from centerline to centerline. If there is a flood plain it extends beyond the meander belt. The meander is then said to be free - it can be found anywhere in the flood plain. If there is no flood plain the meanders are fixed.

Various mathematical formulae relate the variables of the meander geometry. As it turns out some numerical parameters can be established, which appear in the formulae. The waveform depends ultimately on the characteristics of the flow but the parameters are independent of it and apparently are caused by geologic factors. In general the meander length is 10-14 times, with an average 11 times, the fullbank channel width and 3 to 5 times, with an average of 4.7 times, the radius of curvature at the apex. This radius is 2-3 times the channel width.

Meander of the River Cuckmere in Southern England

A meander has a depth pattern as well. The cross-overs are marked by riffles, or shallow beds, while at the apices are pools. In a pool direction of flow is downward, scouring the bed material. The major volume, however, flows more slowly on the inside of the bend where, due to decreased velocity, it deposits sediment.

The line of maximum depth, or channel, is the thalweg or thalweg line. It is typically designated the borderline when rivers are used as political borders. The thalweg hugs the outer banks and returns to center over the riffles. The meander arc length is the distance along the thalweg over one meander. The river length is the length along the centerline.

Formation[link]

Life history of a meander

Spectacular meander scars, oxbow lakes and abandoned meanders in the broad flood plain of the Rio Negro, Argentina. 2010 astronaut photo from ISS.

Meander formation is a result of natural factors and processes. The waveform configuration of a stream is constantly changing. Fluid flows around a bend in a vortex.^[3] Once a channel begins to follow a sinusoidal path, the amplitude and concavity of the loops increase dramatically due to the effect of helical flow sweeping dense eroded material towards the inside of the bend, and leaving the outside of the bend unprotected and therefore vulnerable to accelerated erosion, forming a positive feedback loop. In the words of Elizabeth A. Wood:^[4]

"... this process of making meanders seems to be a self-intensifying process ... in which greater curvature results in more erosion of the bank, which results in greater curvature ...."

The cross-current along the floor of the channel is part of the secondary flow and sweeps dense eroded material towards the inside of the bend.^[5] The cross-current then rises to the surface near the inside and flows towards the outside, forming the helical flow. The greater the curvature of the bend, and the faster the flow, the stronger is the cross-current and the sweeping.^[6]

Due to the conservation of angular momentum the speed on the inside of the bend is faster than on the outside.^[7]

Since the flow velocity is diminished, so is the centrifugal pressure. However, the pressure of the super-elevated column prevails, developing an unbalanced gradient that moves water back across the bottom from the outside to the inside. The flow is supplied by a counter-flow across the surface from the inside to the outside.^[8] This entire situation is very similar to the Tea leaf paradox. This secondary flow carries sediment from the outside of the bend to the inside making the river more meandering.^[9]

As to why streams of any size become sinuous in the first place, there are a number of theories, not necessarily mutually exclusive.

Stochastic theory[link]

The stochastic theory can take many forms but one of the most general statements is that of Scheidegger:^[10]

"The meander train is assumed to be the result of the stochastic fluctuations of the direction of flow due to the random presence of direction-changing obstacles in the river path."

Given a flat, smooth, tilted artificial surface, rainfall runs off it in sheets, but even in that case adhesion of water to the surface and cohesion of drops produce rivulets at random. Natural surfaces are rough and erodible to different degrees. The result of all the physical factors acting at random is channels that are not straight, which then progressively become sinuous. Even channels that appear to be straight have a sinuous thalweg that leads eventually to a sinuous channel.

Equilibrium theory[link]

In the equilibrium theory, meanders decrease the stream gradient until an equilibrium between the erodibility of the terrain and the transport capacity of the stream is reached.^[11] A mass of water descending must give up potential energy, which, given the same velocity at the end of the drop as at the beginning, is removed by interaction with the material of the stream bed. The shortest distance; that is, a straight channel, results in the highest energy per unit of length, disrupting the banks more, creating more sediment and aggrading the stream. The presence of meanders allows the stream to adjust the length to an equilibrium energy per unit length in which the stream carries away all the sediment that it produces.

Geomorphic and morphotectonic theory[link]

Geomorphic refers to the surface structure of the terrain. Morphotectonic means having to do with the deeper, or tectonic (plate) structure of the rock. The features included under these categories are not random and guide streams into non-random paths. They are predictable obstacles that instigate meander formation by deflecting the stream. For example, the stream might be guided into a fault line (morphotectonic).

Associated landforms[link]

Erosion mechanics[link]

The depositional slip off slope is on the left whilst there is a small river cliff to the right. River Ashes Hollow, UK.

Most meanders occur in the region of a river channel with shallow gradients, a well-developed floodplain, and cohesive floodplain material. Deposition of sediment occurs on the inner edge, because the secondary flow of the river^[12] sweeps and rolls sand, rocks and other submerged objects across the bed of the river towards the inside radius of the river bend, creating a slip-off slope called a point bar. Erosion is greater on the outside of the bend where the soil is not protected by deposits of sand and rocks. The current on the outside bend is more effective in eroding the unprotected soil, and the inside bend receives steadily increasing deposits of sand and rocks, and the meander tends to grow in the direction of the outside bend, forming a small cliff called a cut bank. This can be seen in areas where willows grow on the banks of rivers; on the inside of meanders, willows are often far from the bank, whilst on the outside of the bend, the roots of the willows are often exposed and undercut, eventually leading the trees to fall into the river. This demonstrates the river's movement. Slumping usually occurs on the concave sides of the banks resulting in mass movements such as slides.

Deposits[link]

Incised meanders[link]

Glen Canyon, USA

If the slope of an established meandering stream is suddenly increased, it will resume downward erosion – this happens when the base level of the stream is reduced, for example due to tectonic uplift of the region, a global fall in sea-level, collapse of a moraine-dammed lake downstream, or by capture of the stream by a steeper one. As the stream erodes downwards, its established meandering pattern will remain as a deep valley known as an incised meander or entrenched meander. Rivers in the Colorado Plateau and streams in the Ozark Plateau are noted for these incised meanders.

Goosenecks of the San Juan River, SE Utah. Note cut-off meander at right center.

Oxbow lakes[link]

Oxbow lakes are created when growing meanders intersect each other and cut off a meander loop, leaving it without an active cutting stream. Over a period of time, these oxbow lakes tend to dry out or fill in with sediments.

Abandoned meander (rincon)[link]

Look up rincón in Wiktionary, the free dictionary.

Sometimes an incised meander is cut off, similar to an oxbow lake. The resulting landform is known as an abandoned meander. In the southwest United States it is also known as a rincon. One dramatic example, on Lake Powell, is called "The Rincon."

Scroll-bars[link]

Meanders, scroll-bars and oxbow lakes in the Songhua River

Scroll-bars are a result of continuous lateral migration of a meander loop that creates an asymmetrical ridge and swale topography^[13] on the inside of the bends. The topography is generally parallel to the meander and is related to migrating bar forms and back bar chutes^[14] which carve sediment out from the outside of the curve and deposit sediment in the slower flowing water on the inside of the loop, in a process called lateral accretion. Scroll-bar sediments are characterized by cross-bedding and a pattern of fining upward.^[15] These characteristics are a result of the dynamic river system, where larger grains are transported during high energy flood events and then gradually die down, depositing smaller material with time (Batty 2006). Deposits for meandering rivers are generally homogeneous and laterally extensive unlike the more heterogeneous braided river deposits.^[16] There are two distinct patterns of scroll-bar depositions; the eddy accretion scroll bar pattern and the point-bar scroll pattern. When looking down the river valley they can be distinguished because the point-bar scroll patterns are convex and the eddy accretion scroll bar patterns are concave.^[17] Scroll bars often look lighter at the tops of the ridges and darker in the swales. This is because the tops can be shaped by wind, either adding fine grains or by keeping the area unvegetated, while the darkness in the swales can be attributed to silts and clays washing in during high water periods. This added sediment in addition to water that catches in the swales is in turn is a favorable environment for vegetation that will also accumulate in the swales.

Derived quantities[link]

The meander ratio^[18] or sinuosity index^[19] is a means of quantifying how much a river or stream meanders (how much its course deviates from the shortest possible path). It is calculated as the length of the stream divided by the length of the valley. A perfectly straight river would have a meander ratio of 1 (it would be the same length as its valley), while the higher this ratio is above 1, the more the river meanders.

Sinuosity indices are calculated from the map or from an aerial photograph measured over a distance called the reach, which should be at least 20 times the average fullbank channel width. The length of the stream is measured by channel, or thalweg, length over the reach, while the bottom value of the ratio is the downvalley length or air distance of the stream between two points on it defining the reach.

The sinuosity index plays a part in mathematical descriptions of streams. The index may need to be elaborated because the valley may meander as well; i.e., the downvalley length is not identical to the reach. In that case the valley index is the meander ratio of the valley while the channel index is the meander ratio of the channel. The channel sinuosity index is the channel length divided by the valley length and the standard sinuosity index is the channel index divided by the valley index. Distinctions may become even more subtle.^[20]

Sinuosity Index has a non-mathematical utility as well. Streams can be placed in categories arranged by it; for example, when the index is between 1 to 1.5 the river is sinuous, but if between 1.5 and 4, then meandering. The index is a measure also of stream velocity and sediment load, those quantities being maximized at an index of 1 (straight).

See also[link]

• Riffle-pool sequence
• Helicoidal flow
• Baer's law
• Meander cutoffs in Avulsion (river)
• Meander scar
• Crevasse splay
• Jet stream exhibits meander also

References and notes[link]

Bibliography[link]

• Hickin, Edward J. (2003). "Meandering Channels". In Middleton, Gerard V.. Encyclopedia of Sediments and Sedimentary Rocks. Kluwer Academic Encyclopedia of Earth Sciences. Dordrecht; Boston: Kluwer Academic Publishers. pp. 430–434. ISBN 1-4020-0872-4. 
• Leopold, Luna B.; Langbein, W.B. (June 1966). "River Meanders". Scientific American: 60. 
• Thonemann, P., The Maeander Valley: A historical geography from Antiquity to Byzantium (Cambridge, 2011) (Greek Culture in the Roman World Series).

External links[link]

Wikimedia Commons has media related to: Meanders

• Movshovitz, Nitsa; Hadar Alla Shmuklar (2006-01-01). "River Meandering and a Mathematical Model of this Phenomenon". Physicalplus (Israel Physical Society (IPS)) (7). http://physicaplus.org.il/zope/home/en/1124811264/1141060775rivers_en. Retrieved 2008-02-23. 

Yuri Gagarin Юрий Гагарин
Soviet cosmonaut The first human in space
Nationality	Soviet
Status	Deceased
Born	(1934-03-09)9 March 1934 Klushino, Russian SFSR, Soviet Union
Died	27 March 1968(1968-03-27) (aged 34) Novosyolovo, Russian SFSR, Soviet Union
Other occupation	Pilot
Rank	Colonel (Polkovnik), Soviet Air Forces
Time in space	1 hour, 48 minutes
Selection	Air Force Group 1
Missions	Vostok 1
Mission insignia
Awards

Yuri Alekseyevich Gagarin (Russian: Ю́рий Алексе́евич Гага́рин,^[1] Russian pronunciation: [ˈjurʲɪj ɐlʲɪˈksʲejɪvʲɪtɕ ɡɐˈɡarʲɪn]; 9 March 1934 – 27 March 1968) was a Soviet pilot and cosmonaut. He was the first human to journey into outer space, when his Vostok spacecraft completed an orbit of the Earth on 12 April 1961.

Gagarin became an international celebrity, and was awarded many medals and honours, including Hero of the Soviet Union, the nation's highest honour. Vostok 1 marked his only spaceflight, but he served as backup crew to the Soyuz 1 mission (which ended in a fatal crash). Gagarin later became deputy training director of the Cosmonaut Training Centre outside Moscow, which was later named after him. Gagarin died in 1968 when a MiG 15 training jet he was piloting crashed.

Early life[link]

Yuri Gagarin was born in the village of Klushino near Gzhatsk (now in Smolensk Oblast, Russia), on 9 March 1934.^[2] The adjacent town of Gzhatsk was renamed Gagarin in 1968 in his honour. His parents, Alexey Ivanovich Gagarin and Anna Timofeyevna Gagarina, worked on a collective farm.^[3] While manual labourers are described in official reports as "peasants", his mother was reportedly a voracious reader, and his father a skilled carpenter. Yuri was the third of four children, and his elder sister helped raise him while his parents worked. Like millions of people in the Soviet Union, the Gagarin family suffered during Nazi occupation in World War II. After a German officer took over their house, the family constructed a small mud hut where they spent a year and nine months until the end of the occupation.^[4] His two older siblings were deported to Nazi Germany for slave labour in 1943, and did not return until after the war. In 1946, the family moved to Gzhatsk.^[4]

Career in the Soviet Air Force[link]

In his youth, Gagarin became interested in space and planets.^[5] After studying for one year at a vocational technical school in Lyubertsy, Gagarin was selected for further training at a technical high school in Saratov. While there, he joined the "AeroClub", and learned to fly a light aircraft, a hobby that would take up an increasing portion of his time.

In 1955, after completing his technical schooling, he entered military flight training at the Orenburg Pilot's School. While there he met Valentina Goryacheva, whom he married in 1957, after gaining his pilot's wings in a MiG-15. Post-graduation, he was assigned to Luostari airbase in Murmansk Oblast, close to the Norwegian border, where terrible weather made flying risky. He became a Lieutenant in the Soviet Air Force on 5 November 1957 and on 6 November 1959 he received the rank of Senior Lieutenant.^[6]

Career in the Soviet space program[link]

Selection and training[link]

In 1960, after the search and selection process, Yuri Gagarin was chosen with 19 other pilots for the Soviet space program. Gagarin was further selected for an elite training group known as the Sochi Six from which the first cosmonauts of the Vostok programme would be chosen. Gagarin and other prospective cosmonauts were subjected to experiments designed to test physical and psychological endurance; he also underwent training for the upcoming flight. Out of the twenty selected, the eventual choices for the first launch were Gagarin and Gherman Titov because of their performance in training, as well as their physical characteristics — space was at a premium in the small Vostok cockpit and both men were rather short. Gagarin was 1.57 metres (5 ft 2 in) tall, which was an advantage in the small Vostok cockpit.^[3]

In August 1960, when Gagarin was one of 20 possible candidates, an Air Force doctor evaluated his personality as follows:

[M]odest; embarrasses when his humor gets a little too racy; high degree of intellectual development evident in Yuriy; fantastic memory; distinguishes himself from his colleagues by his sharp and far-ranging sense of attention to his surroundings; a well-developed imagination; quick reactions; persevering, prepares himself painstakingly for his activities and training exercises, handles celestial mechanics and mathematical formulae with ease as well as excels in higher mathematics; does not feel constrained when he has to defend his point of view if he considers himself right; appears that he understands life better than a lot of his friends.

—Soviet Air Force doctor, ^[7]

Gagarin was also a favoured candidate by his peers. When the 20 candidates were asked to anonymously vote for which other candidate they would like to see as the first to fly, all but three chose Gagarin.^[8] One of these candidates, Yevgeny Khrunov, believed that Gagarin was very focused, and was demanding of himself and others when necessary.^[9]

Gagarin kept physically fit throughout his life, and was a keen sportsman. Cosmonaut Valery Bykovsky wrote:

In addition to being a keen ice hockey player, Gagarin was also a basketball fan, and coached the Saratov Industrial Technical School team, as well as being an umpire/referee.^[11]

Space flight[link]

Vostok I capsule on display at the RKK Energiya museum

On 12 April 1961, aboard the Vostok 3KA-3 (Vostok 1), Gagarin became both the first human to travel into space, and the first to orbit the earth. His call sign was Kedr (Siberian Pine, Russian: Кедр).^[12]

In his post-flight report, Gagarin recalled his experience of spaceflight, having been the first human in space:

The feeling of weightlessness was somewhat unfamiliar compared with Earth conditions. Here, you feel as if you were hanging in a horizontal position in straps. You feel as if you are suspended.^[13]

Following the flight, Gagarin told the Soviet leader Nikita Khrushchev that during reentry he had whistled the tune "The Motherland Hears, The Motherland Knows" (Russian: "Родина слышит, Родина знает").^[14][15] The first two lines of the song are: "The Motherland hears, the Motherland knows/Where her son flies in the sky".^[16] This patriotic song was written by Dmitri Shostakovich in 1951 (opus 86), with words by Yevgeniy Dolmatovsky.

Some sources have claimed that Gagarin commented during the flight, "I don't see any God up here." However, no such words appear in the verbatim record of his conversations with Earth-based stations during the spaceflight.^[17] In a 2006 interview, Gagarin's friend Colonel Valentin Petrov stated that the cosmonaut never said such words, and that the quote originated from Nikita Khrushchev's speech at the plenum of the Central Committee of the CPSU about the state's anti-religion campaign, saying "Gagarin flew into space, but didn't see any god there."^[18] Petrov also said that Gagarin had been baptised into the Orthodox Church as a child, and a 2011 Foma magazine article quoted the rector of the Orthodox church in Star City saying, "Gagarin baptized his elder daughter Elena shortly before his space flight; and his family used to celebrate Christmas and Easter and keep icons in the house."^[19]

After Vostok 1[link]

A postcard with an image of Yuri Gagarin

After the flight, Gagarin became a worldwide celebrity, touring widely abroad. He visited Italy, Germany, Canada, Brazil, Japan, Egypt^[20] and Finland to promote the Soviet Union's accomplishment of putting the first human in space. He visited the United Kingdom three months after the Vostok 1 mission, visiting the cities of London and Manchester, the latter of which has been fondly remembered by locals.^[21][22]

The sudden rise to national and international fame took its toll on Gagarin. In attending various functions and receptions in his honour, he consumed large amounts of vodka and other alcoholic beverages, even though otherwise he was not a regular drinker. His physical appearance changed and he became noticeably heavier. The attention of female fans took a toll on his marriage. It was rumoured that his wife once caught him in a hotel room with another woman and Gagarin jumped out of the second floor window and hit his face on a kerbstone, which resulted in a deep cut above his left eye. The scar remained visible after the incident.^[23]

In 1962, he began serving as a deputy to the Supreme Soviet of the Soviet Union. He later returned to Star City, the cosmonaut facility, where he spent seven years working on designs for a reusable spacecraft. He became Lieutenant Colonel (or Podpolkovnik) of the Soviet Air Force on 12 June 1962 and on 6 November 1963 he received the rank of Colonel (Polkovnik) of the Soviet Air Force.^[6] Soviet officials tried to keep him away from any flights, being worried of losing their hero in an accident. Gagarin was backup pilot for his friend Vladimir Komarov in the Soyuz 1 flight, which was launched despite Gagarin's protests that additional safety precautions were needed.^[24] When Komarov's flight ended in a fatal crash, Gagarin was ultimately banned from training for and participating in further spaceflights.

Gagarin had become deputy training director of the Star City cosmonaut training base. At the same time, he began to re-qualify as a fighter pilot.

Death[link]

On 27 March 1968, while on a routine training flight from Chkalovsky Air Base, he and flight instructor Vladimir Seryogin died in a MiG-15UTI crash near the town of Kirzhach. The bodies of Gagarin and Seryogin were cremated and the ashes were buried in the walls of the Kremlin on Red Square. Gagarin was survived by his wife Valentina, and daughters Elena and Galina. Elena Gagarina, Yuri's elder daughter, is an art historian who works as a director-general of the Moscow Kremlin Museums since 2001.^[25] His younger daughter, Galina, is a department chair at Plekhanov Russian Economic University in Moscow.^[26]

Cause of jet crash[link]

The cause of the crash that killed Gagarin is not entirely certain, and has been subject to speculation and conspiracy theories over the ensuing decades.

Soviet documents declassified in March 2003 showed that the KGB had conducted their own investigation of the accident, in addition to one government and two military investigations. The KGB's report dismissed various conspiracy theories, instead indicating that the actions of air base personnel contributed to the crash. The report states that an air traffic controller provided Gagarin with outdated weather information, and that by the time of his flight, conditions had deteriorated significantly. Ground crew also left external fuel tanks attached to the aircraft. Gagarin's planned flight activities needed clear weather and no outboard tanks. The investigation concluded that Gagarin's aircraft entered a spin, either due to a bird strike or because of a sudden move to avoid another aircraft. Because of the out-of-date weather report, the crew believed their altitude to be higher than it actually was, and could not properly react to bring the MiG-15 out of its spin.^[27]

In his 2004 book Two Sides of the Moon, Alexey Leonov recounts that he was flying a helicopter in the same area that day when he heard "two loud booms in the distance." Corroborating other theories, his conclusion is that a Sukhoi jet (which he identifies as a Su-15 'Flagon') was flying below its minimum allowed altitude, and "without realizing it because of the terrible weather conditions, he passed within 10 or 20 meters of Yuri and Seregin's plane while breaking the sound barrier." The resulting turbulence would have sent the MiG into an uncontrolled spin. Leonov believes the first boom he heard was that of the jet breaking the sound barrier, and the second was Gagarin's plane crashing.^[28]

Another theory, advanced by the original crash investigator in 2005, hypothesizes that a cabin air vent was accidentally left open by the crew or the previous pilot, leading to oxygen deprivation and leaving the crew incapable of controlling the aircraft.^[29] A similar theory, published in Air & Space magazine, is that the crew detected the open vent and followed procedure by executing a rapid dive to a lower altitude. This dive caused them to lose consciousness and crash.^[30]

On 12 April 2007, the Kremlin vetoed a new investigation into the death of Gagarin. Government officials said that they saw no reason to begin a new investigation.^[31]

In April 2011, documents from a 1968 commission set up by the Central Committee of the Communist Party to investigate the accident were declassified. Those documents revealed that the commission's original conclusion was that Gagarin or Seryogin had maneuvered sharply either to avoid a weather balloon, leading the jet into a "super-critical flight regime and to its stalling in complex meteorological conditions," or to avoid "entry into the upper limit of the first layer of cloud cover".^[32]

Legacy and tributes[link]

Legacy[link]

Aside from his short stature at 1.57 metres (5 ft 2 in), one of Gagarin's most notable traits was his smile.^[33] Many commented on how Gagarin's smile gained the attention of many in the crowd on the frequent tours Gagarin did in the months after the Vostok 1 mission success.^[34]

Gagarin also garnered a reputation as an adept public figure. When he visited Manchester in the United Kingdom, it was pouring with rain; however, Gagarin insisted that the car hood remain back so that the cheering crowds could catch a glimpse of him. Gagarin stated, "If all these people have turned out to welcome me and can stand in the rain, so can I." Gagarin refused an umbrella and remained standing in his open-top Bentley so that the cheering crowds could still see him.^[35]

Sergei Korolev, one of the masterminds behind the early years of the Soviet space program, later said that Gagarin possessed a smile "that lit up the Cold War".^[36]

Gagarin was also honored by the American space program during Apollo 11 when astronauts Neil Armstrong and Buzz Aldrin left on the surface of the Moon a memorial bag containing medals commemorating Gagarin and fellow cosmonaut Vladimir Komarov. On 1 August 1971, Apollo 15 astonauts David Scott and James Irwin left the Fallen Astronaut on the surface of the Moon as a memorial to all the American astronauts and Soviet cosmonauts that died in the Space Race, with Yuri Gagarin listed among 14 others.

Tributes[link]

Russian Rouble commemorating Gagarin in 2001

There were two commemorative coins issued in the Soviet Union to commemorate 20th and 30th anniversaries of his flight: 1 ruble coin (1981, copper-nickel) and 3 ruble coin (1991, silver). In 2001, to commemorate the 40th anniversary of Gagarin's flight, a series of four coins bearing his likeness was issued in Russia: 2 ruble coin (copper-nickel), 3 ruble coin (silver), 10 ruble coin (brass-copper, nickel), and 100 ruble coin (silver).^[37] In 2011, Russia issued a 1,000 ruble coin (gold) and 3 ruble coin (silver) to mark the 50th anniversary of his flight.^[38]

Yuri Gagarin statue in London, near Admiralty Arch

Gagarin Raion in the Sevastopol city (Ukraine) was named after him during the Soviet Union.

In 2008, the Kontinental Hockey League named their championship trophy the Gagarin Cup.^[39]

In a 2010 Space Foundation survey, Gagarin was ranked as the #6 most popular space hero, tied with Star Trek's fictional Capt. James T. Kirk.^[40]

In January 2011, Armenian airline Armavia named their first Sukhoi Superjet 100 in Gagarin's honour.^[41]

On 14 July 2011, a copy of the Yuri Gagarin Statue from outside his former school in Lyubertsy was unveiled at the Admiralty Arch end of The Mall in London, opposite the permanent sculpture of James Cook.^[42]

50th anniversary[link]

The 50th anniversary of Gagarin's journey into space was marked in 2011 by tributes around the world. A film entitled First Orbit was shot from the International Space Station, combining the original flight audio with footage of the route taken by Gagarin.^[43] The Russian, American, and Italian Expedition 27 crew aboard the ISS sent a special video message to wish the people of the world a "Happy Yuri's Night", wearing shirts with an image of Gagarin.^[44]

Swiss-based German watchmaker Bernhard Lederer created a limited edition of 50 Gagarin Tourbillons to commemorate the 50th anniversary of Yuri Gagarin's flight.^[45]

The launch of Soyuz TMA-21 on 4 April 2011 was devoted to the 50th anniversary of the first manned space mission.^[46]

Honours and awards[link]

This article incorporates information from the Russian Wikipedia.

• Hero of the Soviet Union (14 April 1961)
• Pilot-Cosmonaut of the USSR (27 June 1961)
• Hero of Socialist Labour (Czechoslovak Socialist Republic, 29 April 1961)
• Hero of Socialist Labour, (People's Republic of Bulgaria, 24 May 1961)
• Hero of Labour, (Democratic Republic of Vietnam, 28 April 1962)
• President of the Soviet-Cuban friendship
• Honorary Member of the Society, "the Finland-Soviet Union"
• Honorary member of the International Academy of Astronautics (1966)
• Honored Master of Sports of the USSR (1961, title obtained as a reward for a space flight)
• Military Pilot 1st Class (1961, awarded the qualification of space flight)
• Honorary suvorovets (Moscow Suvorov Military School, 1962)
• Order of Lenin (USSR, 14 April 1961)
• Order of Georgi Dimitrov (Bulgaria, 24 May 1961)
• Order of the Star, 2nd Class (Indonesia, 10 June 1961)
• Cross of Grunwald, 1st class (Poland, 20 June 1961)
• The first Commander of the Order "Playa Giron" (Cuba, 18 July 1961)
• "For achievements in aeronautics" (Brazil, 2 August 1961)
• Order of the Flag of the Hungarian Republic, 1st class with diamonds (Hungary, 21 August 1961)
• Order of Karl Marx (German Democratic Republic, 22 October 1963)
• Order of Klement Gottwald (Czechoslovak Socialist Republic)
• Order of the Nile (Egypt, 31 January 1962)
• Order of the African Star (Liberia, 6 February 1962)
• Jubilee Medal "40 Years of the Armed Forces of the USSR" (USSR, 1958)
• Jubilee Medal "Twenty Years of Victory in the Great Patriotic War 1941-1945" (USSR, 9 May 1965)
• Medal "For Impeccable Service", 3rd class (Soviet Union, March 1966)
• Jubilee Medal "50 Years of the Armed Forces of the USSR" (USSR, January 1968) [32]
• Konstantin Tsiolkovsky Gold Medal "for outstanding work in the field of interplanetary communications" (USSR)
• Medal of de Lavaux (FAI)
• Gold Medal of the Austrian Government, 1962
• Gold medal and diploma "Man in Space," the Italian Association of Space
• Gold Medal "For outstanding difference" and the Royal Aero Club Diploma, Sweden
• Gold Medal of the British Society for interplanetary travel, 1961
• Medal of Columbus (Italy)
• Gold Medal of Saint-Denis (France)
• Gold Medal Award "for courage" of the Fund Matstsotti (Italy), 2007

and others.

Yuri Gagarin was elected an honorary citizen of the cities of Kaluga, Novozybkov, Novocherkassk, Lyubertsy, Sumqayit, Smolensk, Vinnytsia and Sevastopol, Saratov, Komsomolsk-on-Amur, Tyumen (the USSR), Orenburg (Russia), Sofia, Pernik, Plovdiv (Bulgaria), Athens (Greece), Famagusta, Limassol (Cyprus), Saint-Denis (France), and Teplice (Czech Republic). He was also awarded the golden keys to the gates of the city of Cairo and Alexandria (Egypt).

See also[link]

• Cosmonautics Day – holiday celebrated in Russia and other former USSR countries on 12 April
• Yuri's Night – international celebration held every 12 April
• Kosmonaut Yuri Gagarin – Soviet space research ship

References[link]

Sources[link]

• Siddiqi, Asif A (2000). Challenge to Apollo: The Soviet Union and the Space Race, 1945-1974. Washington, D.C.: NASA. OCLC 48909645. SP-2000-4408.  Part 1 (page 1-500), Part 2 (page 501-1011).
• Gavrilin, Vyacheslav Mikhailovich (1973). Sportsmen of the Soviet Army. Moscow: Novosti Press Agency. OCLC 23374154. 

Further reading[link]

• Andrew L. Jenks (2012). The Cosmonaut Who couldn't Stop Smiling: The Life and Legend of Yuri Gagarin. Northern Illinois University Press. ISBN 978-0-87580-447-7. 
• Cole, Michael D (1995). Vostok 1: First Human in Space. Springfield: Enslow. ISBN 0-89490-541-4. 
• Doran, Jamie; Bizony, Piers (1998). Starman: The Truth Behind the Legend of Yuri Gagarin. London: Bloomsbury. ISBN 0-7475-4267-8. 

External links[link]

Wikiquote has a collection of quotations related to: Yuri Gagarin

Wikimedia Commons has media related to: Yuri Gagarin

External images
Memorial to Gagarin and Seregin at crash location
	Memorial obelisk photo
	Memorial obelisk closeup photo
	Coordinates 56°02′48″N 39°01′35″E / 56.04664°N 39.0265°E / 56.04664; 39.0265

• Gagarin's Start - short video by Roscosmos including the preparation, Gagarin's flight, and Gagrin back on Earth
• Episode 47 of astrotalkuk.org Recording from the unveiling of Yuri Gagarin Statue event in London on 14 July 2011
• Rare B&W video with some audio, of Yuri Gagarin in Manchester 12 July 1961
• Feature Film First Orbit from firstorbit.org
• Yuri Gagarin - The First to Fly
• Gagarin's photos
• Yuri Gagarin: First Man in Space - slideshow by Life magazine
• Obituary, NY Times, 28 March 1968 Yuri Gagarin Killed As Test Plane Falls
• (Russian) Юрий Гагарин. Дорога в космос — his book in Russian (HTML)
• (Russian) Photo, Audio and Video with Yuri Gagarin, online version of CD created to his 70th anniv. on the homepage of Russian state archive for scientific-technical documentation (RGANTD).
• (Russian) Article in online Encyclopedia of cosmonautics A lot of information about the first human's flight to space.
• (Russian) Gagarin's flight 3D visualization — contains the real record of his conversation with the Earth during the spaceflight
• (Russian) Annotated transcript of Gagarin's radio conversations with ground stations, starting 2hrs (4:10 UTC) before launch
• Gagarin — detailed biography at Encyclopedia Astronautica
• List (with photos) of Gagarin statues
• (Finnish) (Russian) 11 minutes long interview of Yuri Gagarin by The Finnish Broadcasting Company in 1961
• Yuri's Night - World Space Party
• 50th Anniversary of Yuri Gagarin's flight into space
• Yuri Gagarin's Klushino: Forgotten home of space legend
• Yuri Gagarin at Find a Grave
• Yuri Gagarin footage from 1961
• Yuri Gagarin
• The short film "Soviet Man in Space (1961)" is available for free download at the Internet Archive [more]
• The short film "First Pictures. Soviets Hail Space hero , 1961/04/19 (1961)" is available for free download at the Internet Archive [more]

lez:Гагарин, Юрий Алексеевичvep:Gagarin Jurii