Clyde William Tombaugh
Tombaugh at the Lowell Observatory
Born	February 4, 1906(1906-02-04) Streator, Illinois
Died	January 17, 1997 (aged 90) Las Cruces, New Mexico
Nationality	American
Occupation	Astronomer
Known for	Discovery of Pluto

Clyde William Tombaugh (February 4, 1906 – January 17, 1997) was an American astronomer. Events 211 - Roman Emperor Septimius Severus dies leaving the Roman Empire in the hands of his two quarrelsome sons Year 1906 ( MCMVI) was a Common year starting on Monday (link will display full calendar of the Gregorian calendar (or a Common year starting Streator is a city in LaSalle and Livingston counties in the U Events 38 BC - Octavian marries Livia Drusilla. 1287 - King Alfonso III of Aragon invades Minorca Year 1997 ( MCMXCVII) was a Common year starting on Wednesday (link will display full 1997 Gregorian calendar Las Cruces is the second most populous city in New Mexico, the County seat of Doña Ana County, and a United States Metropolitan Statistical Area Historically Astronomy was more concerned with the classification and description of phenomena in the sky while Astrophysics attempted to explain these phenomena Events 211 - Roman Emperor Septimius Severus dies leaving the Roman Empire in the hands of his two quarrelsome sons Year 1906 ( MCMVI) was a Common year starting on Monday (link will display full calendar of the Gregorian calendar (or a Common year starting Events 38 BC - Octavian marries Livia Drusilla. 1287 - King Alfonso III of Aragon invades Minorca Year 1997 ( MCMXCVII) was a Common year starting on Wednesday (link will display full 1997 Gregorian calendar The United States of America —commonly referred to as the Historically Astronomy was more concerned with the classification and description of phenomena in the sky while Astrophysics attempted to explain these phenomena

Tombaugh is best known for discovering the dwarf planet Pluto in 1930, but also discovered many asteroids, and called for serious scientific research of unidentified flying objects. A dwarf planet, as defined by the International Astronomical Union (IAU is a Celestial body Orbiting the Sun that is massive enough to be rounded Year 1930 ( MCMXXX) was a Common year starting on Wednesday (link will display 1930 calendar of the Gregorian calendar. Asteroids, sometimes called Minor planets or planetoids', are bodies—primarily of the inner Solar System —that are smaller than planets but

Biography

Tombaugh was born in Streator^[1], LaSalle County, Illinois. Streator is a city in LaSalle and Livingston counties in the U LaSalle County is a County located in the US state of Illinois.

After his family moved to Burdett, Kansas, Tombaugh built his first telescope and sent drawings of his observations of Jupiter and Mars to the Lowell Observatory. Burdett is a city in Pawnee County, Kansas, United States. The population was 256 at the 2000 census. A telescope is an instrument designed for the observation of remote objects and the collection of Electromagnetic radiation. Lowell Observatory is an astronomical Observatory in Flagstaff Arizona. These resulted in a job offer. Tombaugh was employed at the Lowell Observatory from 1929 to 1945. Lowell Observatory is an astronomical Observatory in Flagstaff Arizona. Year 1929 ( MCMXXIX) was a Common year starting on Tuesday (link will display the full calendar of the Gregorian calendar. Year 1945 ( MCMXLV) was a Common year starting on Monday (link will display the full calendar

Following his discovery of Pluto, Tombaugh earned astronomy degrees from the University of Kansas and Northern Arizona University. The University of Kansas (often referred to as KU or just Kansas) is a public research university with campuses located in Lawrence, Kansas City Northern Arizona University (NAU is a Public university in Flagstaff Arizona in the United States. He worked at the White Sands Missile Range in the early 1950s, and taught astronomy at New Mexico State University from 1955 until his retirement in 1973. White Sands Missile Range (WSMR is a Rocket range of almost area the largest military installation in the United States New Mexico State University, or NMSU is a Land-grant university that has its main campus in Las Cruces, New Mexico. Year 1955 ( MCMLV) was a Common year starting on Saturday (link displays the 1955 Gregorian calendar) Year 1973 ( MCMLXXIII) was a Common year starting on Monday (link will display full calendar of the 1973 Gregorian calendar. He died in Las Cruces, New Mexico, 1997 and was survived by his wife Patricia, daughter Annette and son Alden, a retired banker. Las Cruces is the second most populous city in New Mexico, the County seat of Doña Ana County, and a United States Metropolitan Statistical Area ^[2]

Tombaugh was an active Unitarian-Universalist. Unitarian Universalism ( UUism) is a theologically liberal Religion characterized by its support for a "free and responsible search for truth

The asteroid 1604 Tombaugh,^[3] discovered in 1931, is named after him. Asteroids, sometimes called Minor planets or planetoids', are bodies—primarily of the inner Solar System —that are smaller than planets but Year 1931 ( MCMXXXI) was a Common year starting on Thursday (link will display full 1931 calendar of the Gregorian calendar. He himself discovered 14 asteroids, beginning with 2839 Annette in 1929, mostly as a by-product of his search for Pluto and his further searches for other celestial objects. Year 1929 ( MCMXXIX) was a Common year starting on Tuesday (link will display the full calendar of the Gregorian calendar. Tombaugh named some of them after his wife, children and grandchildren. The Royal Astronomical Society awarded him the Jackson-Gwilt Medal in 1931. The Royal Astronomical Society (RAS is a Learned society that began as the Astronomical Society of London in 1820 to support astronomical research The Jackson-Gwilt Medal of the Royal Astronomical Society has been awarded regularly since 1897 for the invention improvement or development of astronomical instrumentation Year 1931 ( MCMXXXI) was a Common year starting on Thursday (link will display full 1931 calendar of the Gregorian calendar.

Some of his ashes are being carried on the New Horizons spacecraft which is traveling towards Pluto. New Horizons is a Robotic spacecraft mission by NASA currently underway

Discovery of Pluto

Tombaugh created his photographic plates using this astrograph. An Astrograph ( astrographic camera) is a telescope designed for the sole purpose of Astrophotography.

While a young researcher working for the Lowell Observatory in Flagstaff, Arizona, Tombaugh was given the job to perform a systematic search for a trans-Neptunian planet (also called Planet X), which had been predicted by Percival Lowell and William Pickering. Lowell Observatory is an astronomical Observatory in Flagstaff Arizona. Flagstaff (Kinłání is a city located in northern Arizona, in the southwestern United States A trans-Neptunian object (TNO is any object in the Solar system that Orbits the sun at a greater distance on average than Neptune. Percival Lawrence Lowell ( March 13, 1855 – November 12, 1916) was a businessman author mathematician and Astronomer who fueled William Henry Pickering ( February 15, 1858 &ndash January 17, 1938) was an American Astronomer, brother of Edward

Tombaugh used the observatory's 13-inch astrograph to take photographs of the same section of sky several nights apart. An Astrograph ( astrographic camera) is a telescope designed for the sole purpose of Astrophotography. He then used a blink comparator to compare the different images. A blink comparator was a viewing apparatus used by Astronomers to find differences between two photographs of the night sky shot using Optical telescopes When he shifted between the two images, a moving object, such as a planet, would appear to jump from one position to another, while the more distant objects such as stars would appear stationary. Tombaugh noticed such a moving object in his search, and subsequent observations showed it to be the object we call Pluto. The discovery was made on Tuesday, February 18, 1930, using images taken in January of the same year. Events 3102 BC - Epoch (origin of the Kali Yuga. 1229 - The Sixth Crusade: Frederick II Holy Year 1930 ( MCMXXX) was a Common year starting on Wednesday (link will display 1930 calendar of the Gregorian calendar.

The photographic plates that were used to discover Pluto.

The name "Pluto" was suggested by Venetia Burney, an 11-year-old English school girl who is still living in England as of 2007, and who therefore lived to see the reclassification of Pluto as a dwarf planet. Venetia Katherine Douglas Phair (née Burney) (born 1919 was the first person to suggest the name Pluto for the object discovered by Clyde W England is a Country which is part of the United Kingdom. Its inhabitants account for more than 83% of the total UK population whilst its mainland Year 2007 ( MMVII) was a Common year starting on Monday of the Gregorian calendar in the 21st century. It won out over numerous other suggestions partly because it was named after the Roman god of the underworld (who was able to render himself invisible) and because Percival Lowell's initials PL formed the first 2 letters. Roman mythology, or more appropriately Latin mythology, refers to the mythological beliefs of the Italic people inhabiting the region of Latium and its Pluto was the Roman god of the underworld known in Latin as Tertius the counterpart of the Greek Hades. Percival Lawrence Lowell ( March 13, 1855 – November 12, 1916) was a businessman author mathematician and Astronomer who fueled The name Pluto was officially adopted on 1 May 1930. Events 305 - Diocletian and Maximian retire from the office of Roman Emperor. Year 1930 ( MCMXXX) was a Common year starting on Wednesday (link will display 1930 calendar of the Gregorian calendar.

Following the discovery of the Kuiper belt objects starting in the 1990s, Pluto began to be seen not as a planet orbiting alone at 40 AU, but as the largest of a group of icy bodies in that region of space. The Kuiper belt (ˈkaɪpɚ to rhyme with "viper" sometimes called the Edgeworth-Kuiper belt, is a region of the Solar System beyond the planets extending After it was shown that at least one such body was larger than Pluto, on August 24, 2006 the International Astronomical Union (IAU) reclassified Pluto, grouping it with two similarly sized "dwarf planets" rather than with the eight "classical planets". Events 49 BC - Julius Caesar 's General Gaius Scribonius Curio is defeated in the Second Battle of the Bagradas River Year 2006 ( MMVI) was a Common year starting on Sunday of the Gregorian calendar. A dwarf planet, as defined by the International Astronomical Union (IAU is a Celestial body Orbiting the Sun that is massive enough to be rounded In Astronomy, the naked-eye planets are the five Planets of our Solar system that can be discerned with the Naked eye without much difficulty

Tombaugh's widow Patricia stated after the IAU's decision that while Clyde may have been disappointed with the change since he had resisted attempts to remove Pluto's planetary status in his lifetime, he would have accepted the decision now if he were alive. She notes that Clyde "was a scientist. He would understand they had a real problem when they start finding several of these things flying around the place. "^[4]

Further search

Tombaugh continued searching for some years after the discovery of Pluto, and the lack of further discoveries left him satisfied that no other object of a comparable magnitude existed near the ecliptic. The apparent magnitude ( m) of a celestial body is a measure of its Brightness as seen by an observer on Earth, normalized to the value The ecliptic is the apparent path that the Sun traces out in the sky during the year No more Trans-Neptunian objects were discovered until (15760) 1992 QB₁, in 1992. Year 1992 ( MCMXCII) was a Leap year starting on Wednesday (link will display full 1992 Gregorian calendar)

However, more recently the relatively bright object (136472) 2005 FY₉ has been discovered. It has a relatively high orbital inclination, but at the time of Tombaugh's discovery of Pluto, 2005 FY₉ was only a few degrees from the ecliptic near the border of Taurus and Auriga. Inclination in general is the Angle between a Reference plane and another plane or axis of direction Taurus (it looks like a bull (ˈtɔrəs bull, symbol, Unicode ♉ is one of the Constellations of the Zodiac. Auriga (ɔːˈraɪgə Charioteer) is a northern Constellation. ^[5] Unfortunately, this position was also very near the galactic equator, making it almost impossible to find such an object within the dense concentration of background stars of the Milky Way. The galactic coordinate system is a Celestial coordinate system which is centered on the Sun and is aligned with the apparent center of the Milky Way galaxy The Milky Way (a translation of the Latin Via Lactea, in turn derived from the Greek Γαλαξίας (Galaxias sometimes referred to simply

Asteroids discovered

Tombaugh compared his photographic plates using this blink comparator.

Tombaugh discovered a total of 14 asteroids, during his search for Pluto and years of follow-up searches looking for another candidate for the postulated Planet X. Asteroids, sometimes called Minor planets or planetoids', are bodies—primarily of the inner Solar System —that are smaller than planets but

Interest in UFOs

Tombaugh was probably the most eminent astronomer to have reported seeing Unidentified Flying Objects and to support the Extraterrestrial hypothesis. Events 869 - The Fourth Council of Constantinople is convened to decide about what to do about Patriarch Photius of Constantinople Year 1929 ( MCMXXIX) was a Common year starting on Tuesday (link will display the full calendar of the Gregorian calendar. Events 563 - The Byzantine church Hagia Sophia in Constantinople is dedicated for the second time after being destroyed by Earthquakes Year 1930 ( MCMXXX) was a Common year starting on Wednesday (link will display 1930 calendar of the Gregorian calendar. Events 768 - Carloman I and Charlemagne are crowned Kings of The Franks. Year 1931 ( MCMXXXI) was a Common year starting on Thursday (link will display full 1931 calendar of the Gregorian calendar. Events 869 - The Fourth Council of Constantinople is convened to decide about what to do about Patriarch Photius of Constantinople Year 1929 ( MCMXXIX) was a Common year starting on Tuesday (link will display the full calendar of the Gregorian calendar. Events 597 BC - Babylonians capture Jerusalem, replace Jehoiachin with Zedekiah as king Year 1931 ( MCMXXXI) was a Common year starting on Thursday (link will display full 1931 calendar of the Gregorian calendar. Events 105 BC - Battle of Arausio: The Cimbri inflict the heaviest defeat on the Roman army of Gnaeus Mallius Maximus Year 1931 ( MCMXXXI) was a Common year starting on Thursday (link will display full 1931 calendar of the Gregorian calendar. Events 869 - The Fourth Council of Constantinople is convened to decide about what to do about Patriarch Photius of Constantinople Year 1929 ( MCMXXIX) was a Common year starting on Tuesday (link will display the full calendar of the Gregorian calendar. Events 1294 - Saint Celestine V abdicates the papacy after only five months Celestine hoped to return to his previous life Year 1930 ( MCMXXX) was a Common year starting on Wednesday (link will display 1930 calendar of the Gregorian calendar. Events 105 BC - Battle of Arausio: The Cimbri inflict the heaviest defeat on the Roman army of Gnaeus Mallius Maximus Year 1931 ( MCMXXXI) was a Common year starting on Thursday (link will display full 1931 calendar of the Gregorian calendar. Events 644 - Umar ibn al-Khattab, the second Muslim Caliph, is killed by a Persian slave in Medina. Year 1929 ( MCMXXIX) was a Common year starting on Tuesday (link will display the full calendar of the Gregorian calendar. Events 1400 - Owain Glyndŵr is declared Prince of Wales by his followers Year 1936 ( MCMXXXVI) was a Leap year starting on Wednesday (link will display the full calendar of the Gregorian calendar. Events 539 BC - King Cyrus The Great of Persia marches into the city of Babylon, releasing the Jews from almost Year 1930 ( MCMXXX) was a Common year starting on Wednesday (link will display 1930 calendar of the Gregorian calendar. Events 1138 - A massive earthquake struck Aleppo, Syria. 1531 - Huldrych Zwingli is killed Year 1929 ( MCMXXIX) was a Common year starting on Tuesday (link will display the full calendar of the Gregorian calendar. Events 680 - Battle of Karbala: Shia Imam Husayn bin Ali, the grandson of the Prophet Muhammad, is decapitated Year 1931 ( MCMXXXI) was a Common year starting on Thursday (link will display full 1931 calendar of the Gregorian calendar. The extraterrestrial hypothesis (ETH is the Hypothesis that some UFOs are best explained as being creatures or space aliens from other planets On August 20, 1949, Tombaugh saw several UFOs near Las Cruces, New Mexico. Events 636 - Battle of Yarmouk: Arab forces led by Khalid ibn al-Walid take control of Syria and Palestine Year 1949 ( MCMXLIX) was a Common year starting on Saturday (link will display the full calendar of the Gregorian calendar. Las Cruces is the second most populous city in New Mexico, the County seat of Doña Ana County, and a United States Metropolitan Statistical Area He described them as six to eight rectangular lights, stating:

"I doubt that the phenomenon was any terrestrial reflection, because. . . nothing of the kind has ever appeared before or since. . . I was so unprepared for such a strange sight that I was really petrified with astonishment. "^[6]

A similar shocked response has been reported by many others who claim to have seen mysterious aerial objects.

Another sighting by Tombaugh a year or two later while at a White Sands observatory was of an object of -6 magnitude, four times brighter than Venus at its brightest, going from the zenith to the southern horizon in about 3 seconds. The object executed the same maneuvers as in Tombaugh's first sighting. ^[7]

Tombaugh was also later to report having seen three of the mysterious green fireballs, which suddenly appeared over New Mexico in late 1948 and continued at least through the early 1950s. Green Fireballs is a self-descriptive term used to refer to certain Unidentified flying objects which have been sighted in the sky since the late 1940s Despite this, the final report of Project Twinkle — see external link — claimed that he ". Green Fireballs is a self-descriptive term used to refer to certain Unidentified flying objects which have been sighted in the sky since the late 1940s . . never observed an unexplainable aerial object despite his continuous and extensive observations of the sky. "

In 1956 Tombaugh had the following to say about his various sightings:

"I have seen three objects in the last seven years which defied any explanation of known phenomenon, such as Venus, atmospheric optic, meteors or planes. I am a professional, highly skilled, professional astronomer. In addition I have seen three green fireballs which were unusual in behavior from normal green fireballs . . . I think that several reputable scientists are being unscientific in refusing to entertain the possibility of extraterrestrial origin and nature. Extraterrestrial life is Life originating outside of the Earth. "^[8]

Shortly after this in January 1957, in an Associated Press article in the Alamogordo Daily News titled "Celestial Visitors May Be Invading Earth's Atmosphere," Tombaugh was again quoted on his sightings and opinion about them. The Associated Press ( AP) is an American News agency. The AP is a Cooperative owned by its contributing Newspapers radio Alamogordo Daily News, founded in 1898 is a daily newspaper published in Alamogordo New Mexico.

"Although our own solar system is believed to support no other life than on Earth, other stars in the galaxy may have hundreds of thousands of habitable worlds. Races on these worlds may have been able to utilize the tremendous amounts of power required to bridge the space between the stars. . . "

Tombaugh said he has observed celestial phenomena which he could not explain, but has seen none personally since 1951 or 1952. "These things, which do appear to be directed, are unlike any other phenomena I ever observed. Their apparent lack of obedience to the ordinary laws of celestial motion gives credence. "^[9]

In 1949, Tombaugh had also told the Naval missile director at White Sands Missile Range, Commander Robert McLaughlin, that he had seen a bright flash on Mars in August 1941, which he now attributed to an atomic blast. White Sands Missile Range (WSMR is a Rocket range of almost area the largest military installation in the United States ^[10] Tombaugh also noted that the first atomic bomb tested in New Mexico would have lit up the dark side of the Earth like a neon sign and that Mars was coincidentally quite close at the time, the implication apparently being that the atomic test would have been visible from Mars.

In June 1952, Dr. J. Allen Hynek, an astronomer acting as a scientific consultant to the Air Force's Project Blue Book UFO study, secretly conducted a survey of fellow astronomers on UFO sightings and attitudes while attending an astronomy convention. Josef Allen Hynek ( May 1, 1910 - April 27, 1986) was a United States Astronomer, Professor, and ufologist Project Blue Book was one of a series of systematic studies of Unidentified flying objects (UFOs conducted by the United States Air Force (U Tombaugh and four other astronomers told Hynek about their sightings, including Dr. Lincoln LaPaz of the University of New Mexico. Dr Lincoln LaPaz was an Astronomer from the University of New Mexico and a pioneer in the study of Meteors He was born in Wichita Kansas Tombaugh also told Hynek that his telescopes were at the Air Force's disposal for taking photos of UFOs, if he was properly alerted. ^[11]

Near-Earth satellite search

Clyde Tombaugh (left) discussing search for near-Earth satellites with Dr. Lincoln LaPaz (right), 3 March 1954. Dr Lincoln LaPaz was an Astronomer from the University of New Mexico and a pioneer in the study of Meteors He was born in Wichita Kansas Events 1284 - Statute of Rhuddlan incorporated the Principality of Wales into England 1575 - Indian Year 1954 ( MCMLIV) was a Common year starting on Friday (link will display full 1954 Gregorian calendar) Photo from Albuquerque Journal

Tombaugh's offer may have led to his involvement in a search for near-Earth satellites, first announced in late 1953 and sponsored by the Army Office of Ordnance Research. This article is about artificial satellites For natural satellites also known as moons see Natural satellite. Another public statement was made on the search in March 1954 (photo at right), emphasizing the rationale that such an orbiting object would serve as a natural space station. A space station is an artificial structure designed for Humans to live in Outer space. ^[12] However, according to Donald Keyhoe, later director of the National Investigations Committee on Aerial Phenomena (NICAP), the real reason for the sudden search was because two near-Earth orbiting objects had been picked up on new long-range radar in the summer of 1953, according to his Pentagon source. Donald Edward Keyhoe (June 20 1897 - November 29 1988 was an American Marine Corps officer with some flight experience Writer of many aviation articles The National Investigations Committee On Aerial Phenomena (or NICAP) was a civilian Unidentified flying object research group active in the United States The Pentagon is the Headquarters of the United States Department of Defense, located in Arlington County, Virginia.

By May 1954, Keyhoe was making public statements that his sources told him the search had indeed been successful, and either one or two objects had been found. ^[13] However, the story didn't really break until August 23, 1954, when Aviation Week magazine stated that two satellites had been found only 400 and 600 miles out. Events 79 - Mount Vesuvius begins stirring on the feast day of Vulcan the Roman god of fire Year 1954 ( MCMLIV) was a Common year starting on Friday (link will display full 1954 Gregorian calendar) Aviation Week & Space Technology, often abbreviated Aviation Week or AW&ST, is a weekly Magazine. They were termed "natural satellites" and implied that they had been recently captured, despite this being a virtual impossibility. The next day, the story was in many major newspapers. Dr. LaPaz was implicated in the discovery in addition to Tombaugh. LaPaz had earlier conducted secret investigations on behalf of the Air Force on the green fireballs and other unidentified aerial phenomena over New Mexico. Green Fireballs is a self-descriptive term used to refer to certain Unidentified flying objects which have been sighted in the sky since the late 1940s

LaPaz vehemently denied his involvement in the search, although the New York Times reported on August 29 that a source close to the project said that the story was true and LaPaz was indeed involved, in fact had been the one to spot and identify the objects as natural rather than artificial satellites. Events 708 - Copper coins are minted in Japan for the first time (Traditional Japanese date: August 10, 708) The same source denied the search had anything to do with flying saucers. Flying saucer is the name given to a type of Unidentified flying object (UFO with a disc- or Saucer -shaped body usually described as silver or metallic ^[14]

However, both LaPaz and Tombaugh were to issue public denials that anything had been found. The October 1955 issue of Popular Mechanics magazine reported:

"Professor Tombaugh is closemouthed about his results. Popular Mechanics is an American magazine devoted to Science and Technology. He won't say whether or not any small natural satellites have been discovered. He does say, however, that newspaper reports of 18 months ago announcing the discovery of natural satellites at 400 and 600 miles out are not correct. He adds that there is no connection between the search program and the reports of so-called flying saucers. "^[15]

At a meteor conference in Los Angeles in 1957, Tombaugh reiterated that his four year search for "natural satellites" had been unsuccessful. ^[16] In 1959, Tombaugh was to issue a final report stating that nothing had been found in his search.

In popular culture

In Robert A. Heinlein's 1958 science fiction novel, Have Space Suit—Will Travel, there is a moon base called Tombaugh Station. Robert Anson Heinlein (July 7 1907 – May 8 1988 was an American Novelist and Science fiction Writer. Have Space Suit—Will Travel is a juvenile Science fiction Novel by Robert A And, "Professor Tombaugh (the one the station was named for) was working on a giant electronic telescope to photograph" Pluto.

Wilson Tucker published the 1960 novel To the Tombaugh Station (Ace Double). For the football player of the same name see Bob Tucker (football player.

The 2006 album The Avalanche by Sufjan Stevens includes a song titled "For Clyde Tombaugh". This is a list of notable events in Music that took place in the year 2006. Sufjan Stevens (ˈsuːfjɑːn born July 1, 1975) is an American Singer-songwriter and Musician from Petoskey Michigan

In the Star Trek Universe there is a Federation starship USS Tombaugh, named after the astronomer. It was mentioned in the Star Trek: Voyager episode "Infinite Regress". An infinite regress in a series of propositions arises if the truth of proposition P 1 requires the support of proposition P 2 and for any proposition

In the computer game Descent: FreeSpace — The Great War, there is a Terran station in the Ribos system named after Tombaugh which is obliterated by the Shivan destroyer, Lucifer. Descent FreeSpace — The Great War is a 1998 space combat simulation IBM PC compatible computer game developed by Volition Inc

In Stephen Baxter's 1995 short story "Gossamer," there is a Tombaugh Plateau on Pluto. Stephen Baxter (born 13 November 1957 is a British Hard science fiction Author.

References

1. ^ Tombaugh, Clyde; Patrick Moore (1980). Out of the Darkness: The Planet Pluto. Harrisburg, PA: Stackpole Books, 17. ISBN 0811711633.   "I was born on a farm near Streator, Illinois, on 4 February 1906. "
2. ^ Hill, Karl (Summer 2001). Tombaugh Family Donates Astronomer's Papers to NMSU. Panorama. Retrieved on 2007-02-28. Year 2007 ( MMVII) was a Common year starting on Monday of the Gregorian calendar in the 21st century. Events 202 BC - coronation ceremony of Liu Bang as Emperor Gaozu of Han takes place initiating four centuries of the Han Dynasty 's rule
3. ^ (1604) Tombaugh. Asteroid Dynamic Site. Retrieved on 2007-02-28. Year 2007 ( MMVII) was a Common year starting on Monday of the Gregorian calendar in the 21st century. Events 202 BC - coronation ceremony of Liu Bang as Emperor Gaozu of Han takes place initiating four centuries of the Han Dynasty 's rule
4. ^ Associated Press (2006-08-25). The Associated Press ( AP) is an American News agency. The AP is a Cooperative owned by its contributing Newspapers radio Year 2006 ( MMVI) was a Common year starting on Sunday of the Gregorian calendar. Events 1248 - The Dutch city of Ommen receives city rights and fortification rights from Otto III the Pluto Discoverer Saw It Coming, Says His Widow. CTV. Retrieved on 2007-02-28. Year 2007 ( MMVII) was a Common year starting on Monday of the Gregorian calendar in the 21st century. Events 202 BC - coronation ceremony of Liu Bang as Emperor Gaozu of Han takes place initiating four centuries of the Han Dynasty 's rule
5. ^ based on Minor Planet Center online Minor Planet Ephemeris Service: March 1, 1930: RA 05h51m, Dec: +29. Events 86 BC - Lucius Cornelius Sulla, at the head of a Roman Republic army enters in Athens, removing the Tyrant Year 1930 ( MCMXXX) was a Common year starting on Wednesday (link will display 1930 calendar of the Gregorian calendar. 0
6. ^ Clyde Tombaugh, Ph.D.. UFO Evidence. Retrieved on 2007-02-28. Year 2007 ( MMVII) was a Common year starting on Monday of the Gregorian calendar in the 21st century. Events 202 BC - coronation ceremony of Liu Bang as Emperor Gaozu of Han takes place initiating four centuries of the Han Dynasty 's rule
7. ^ Steiger, Brad (1976). Project Blue Book. Ballantine Books, 280. 0-345-34525-8.  
8. ^ Ledger, Don (2004-09-20). "MMIV" redirects here For the Modest Mouse album see " Baron von Bullshit Rides Again " Events 451 - The Battle of Chalons takes place in North Eastern France. UFO UpDates. Retrieved on 2007-02-28. Year 2007 ( MMVII) was a Common year starting on Monday of the Gregorian calendar in the 21st century. Events 202 BC - coronation ceremony of Liu Bang as Emperor Gaozu of Han takes place initiating four centuries of the Han Dynasty 's rule
9. ^ Clark, Jerry (1997). UFO Encyclopedia: Volume 2, 896.  
10. ^ McLaughlin, Robert (1949-05-12). Letter from Robert McLaughlin to James van Allen. Roswell Proof. Retrieved on 2007-02-28. Year 2007 ( MMVII) was a Common year starting on Monday of the Gregorian calendar in the 21st century. Events 202 BC - coronation ceremony of Liu Bang as Emperor Gaozu of Han takes place initiating four centuries of the Han Dynasty 's rule
11. ^ Steiger, Brad (1976). Project Blue Book. Ballantine Books, 268 - 285. 0-345-34525-8.  
12. ^ “Armed Forces Seeks "Steppingstone to Stars"”, Los Angeles Times, 1954-03-04, <http://www.roswellproof.com/Satellites_LATimes_SciNL_1954.html> 
13. ^ “1 or 2 Artificial Satellites Circling Earth, Says Expert”, San Francisco Examiner: 14, 1954-05-14, <http://www.roswellproof.com/Satellites_Keyhoe_May1954.html> 
14. ^ “Earth 'Satellites' Spur Army Study”, New York Times: 35, 1954-08-29, <http://www.roswellproof.com/Satellites_NYTIMES_1954.html> 
15. ^ Stimson, Jr. , Thomas E. (October 1955), “He Spies on Satellites”, Popular Mechanics: 106, <http://www.roswellproof.com/Satellites_PopMech_Oct55.html> 
16. ^ Los Angeles Times, 1957-09-04 

Further reading

• Falk, Dan, "More than a one-hit wonder", Astronomy, Feb. 2006, 40-45.
• Clyde Tombaugh: Discoverer of Planet Pluto, David H. Levy, Sky Publishing Corporation, March 2006

External links

• Many biographical articles on Clyde Tombaugh
• Quote from Tombaugh on UFOs
• UFO activities of Tombaugh
• Academic paper on Tombaugh's UFO activities and near-earth satellite search
• Final report of Project Twinkle