Fred Lawrence Whipple

Fred Lawrence Whipple (November 5, 1906 – August 30, 2004) was an American astronomer, who worked at the Harvard College Observatory for over 70 years. Amongst his achievements, asteroid and comet discovery, had come up with the "dirty snowball" cometary hypothesis, and invented the Whipple shield.

Fred Lawrence Whipple
Fred Lawrence Whipple at age 95 in 2001 or 2002
BornNovember 5, 1906
DiedAugust 30, 2004 (aged 97)
Known forComposition of comets
Scientific career
InstitutionsHarvard College Observatory
Minor planets discovered: 1 [1]
1252 Celestia 19 February 1933 list


Fred Whipple 1927
Whipple in 1927

Whipple was born on November 5, 1906, in Red Oak, Iowa, as the son of a farmer. An early bout with polio ended his ambition of being a professional tennis player. Whipple studied at Occidental College in Southern California, then majored in mathematics at the University of California at Los Angeles, graduating in 1927. Recollecting his path from mathematics to astronomy, Whipple stated in a 1978 autobiography that his "mathematics major veered [him] through physics and finally focused on astronomy where time, space, mathematics, and physics had a common meeting ground."[2]

After taking a class in astronomy, he enlisted at the University of California, Berkeley where he obtained his PhD in Astronomy in 1931. While in graduate school, he helped map the orbit of the then newly discovered dwarf planet Pluto. He joined Harvard College Observatory in 1931 and studied the trajectories of meteors, confirming that they originated within the solar system rather than from interstellar space. In 1933, he discovered the periodic comet 36P/Whipple and the asteroid 1252 Celestia. He also discovered or co-discovered five other non-periodic comets, the first of which was C/1932 P1 Peltier-Whipple, independently discovered by the famed amateur astronomer Leslie Peltier.

During World War II, he invented a device for cutting tinfoil into chaff to confuse enemy radar tracking Allied aircraft. He was awarded a Certificate of Merit for this in 1948. He also invented a "meteoroid bumper" or "Whipple shield", which protects spacecraft from impact by small particles by vaporizing them.

From 1950 until 1977 he was a professor of Astronomy at Harvard University, including being the Phillips Professor of Astronomy between 1968 and 1977. During these years (in the early 1950s), he wrote a series of influential papers entitled A Comet Model, published in Astrophysical Journal.[3][4][5] In these papers, he proposed the "icy conglomerate" hypothesis of comet composition (later called the "dirty snowball" hypothesis). The basic features of this hypothesis were later confirmed; however, the exact amount (and thus the importance) of ices in a comet is an active field of research, with most of the recently obtained data[6] pointing to a low contribution of ices to a comet's mass (dubbed the "icy dirtball" hypothesis). He also anticipated the era of artificial satellites and organized the members of Operation Moonwatch to track them. These groups were the only ones in the US prepared and ready to make observations when the Soviet Union unexpectedly launched Sputnik I in 1957. He became director of the Smithsonian Astrophysical Observatory when Loyal Blaine Aldrich retired in 1955,[7] and remained in this post until 1973.

Whipple made at least one media appearance, in the science documentary film Target...Earth? (1980). He also appeared in the BBC's coverage of the Giotto encounter with Halley's Comet, in 1986.

Whipple died in 2004, aged 97.



Named after him


  1. ^ "Minor Planet Discoverers (by number)". Minor Planet Center. 4 September 2016. Retrieved 25 September 2016.
  2. ^ Whipple, Fred L. (1978). "The Earth as part of the Universe". Annual Review of Earth and Planetary Sciences. 6 (1): 1–9. Bibcode:1978AREPS...6....1W. doi:10.1146/annurev.ea.06.050178.000245.
  3. ^ Whipple, Fred L. (1950). "A Comet Model. I. The acceleration of Comet Encke". Astrophysical Journal. 111: 375–394. Bibcode:1950ApJ...111..375W. doi:10.1086/145272.
  4. ^ Whipple, Fred L. (1951). "A Comet Model. II. Physical Relations for Comets and Meteors". Astrophysical Journal. 113: 464. Bibcode:1951ApJ...113..464W. doi:10.1086/145416.
  5. ^ Whipple, Fred L. (1955). "A Comet Model. III. The Zodiacal Light". Astrophysical Journal. 121: 750. Bibcode:1955ApJ...121..750W. doi:10.1086/146040.
  6. ^ Keller, Horst Uwe; Küppers, M; et al. (2005). "Deep Impact Observations by OSIRIS Onboard the Rosetta Spacecraft". Science. 310 (5746): 281–3. Bibcode:2005Sci...310..281K. doi:10.1126/science.1119020. PMID 16150976.
  7. ^ "SAO Directors: 1834 - Present". Harvard-Smithsonian Center for Astrophysics. Retrieved 2016-08-14.
  8. ^ Schmadel, Lutz D. (2007). "(1940) Whipple". Dictionary of Minor Planet Names – (1940) Whipple. Springer Berlin Heidelberg. p. 156. doi:10.1007/978-3-540-29925-7_1941. ISBN 978-3-540-00238-3.

Further reading

External links


The Two Micron All-Sky Survey, or 2MASS, was an astronomical survey of the whole sky in the infrared and one of the most ambitious such projects.It took place between 1997 and 2001, in two different locations: at the U.S. Fred Lawrence Whipple Observatory on Mount Hopkins, Arizona (G91), and at the Cerro Tololo Inter-American Observatory in Chile (I02), each using a 1.3-meter telescope for the Northern and Southern Hemisphere, respectively. It was conducted in the short-wavelength infrared at distinct frequency bands near 2 micrometres (or microns), from which the photometric survey with its HgCdTe detectors derives its name.2MASS produced an astronomical catalog with over 300 million observed objects, including minor planets of the Solar System, brown dwarfs, low-mass stars, nebulae, star clusters and galaxies. In addition, 1 million objects were cataloged in the 2MASS Extended Source Catalog (2MASX). The cataloged objects are designated with a "2MASS" and "2MASX"-prefix respectively.

Fred Lawrence Whipple Observatory

The Fred Lawrence Whipple Observatory is an American astronomical observatory owned and operated by the Smithsonian Astrophysical Observatory (SAO); it is their largest field installation outside of their main site in Cambridge, Massachusetts. It is located near Amado, Arizona on the summit, a ridge and at the foot of Mount Hopkins.

Research activities include imaging and spectroscopy of extragalactic, stellar, solar system and extra-solar bodies, as well as gamma-ray and cosmic-ray astronomy.


HAT-P-33b is a planet in the orbit of HAT-P-33, which lies 1,310 light years away from Earth. Its discovery was reported in June 2011, although it was suspected to be a planet as early as 2004. The planet is about three-fourths the mass of Jupiter, but is almost eighty percent larger than Jupiter is; this inflation has, as with the discovery of similar planets WASP-17b and HAT-P-32b, raised the question of what (other than temperature) causes these planets to become so large.HAT-P-33b was difficult to confirm because its star experiences high jitter, which disrupted the ability to obtain accurate measurements. As such, a greater number of radial velocity observations were collected to make the confirmation, although it was later determined that HAT-P-33b could not be determined using the radial velocity method. The planet's confirmation came about after the planet's light curve was collected, and the Blendanal process ruled out most false positive scenarios.

HD 89744

HD 89744 is an F-type subgiant star about 126 light years away in the constellation of Ursa Major. This star has 1.45 times the mass of the Sun, with a projected rotational velocity of 8.0 km s−1. In 2004, stellar companion HD 89744 B (~0.076 solar mass) with a projected separation of 2,456 AU was detected.

Infrared Optical Telescope Array

The Infrared Optical Telescope Array (IOTA) was a stellar interferometer array. IOTA began with an agreement in 1988 among five Institutions, the Smithsonian Astrophysical Observatory, Harvard University, the University of Massachusetts Amherst, the University of Wyoming, and MIT/Lincoln Laboratory, to build a two-telescope stellar interferometer for the purpose of making fundamental astrophysical observations, and also as a prototype instrument on which they could perfect techniques which could later lead to the development of a larger, more powerful array. On site construction went on for all 1993 and 1994, with first fringes in December 1993. It is located at Fred Lawrence Whipple Observatory.

In 2000 the third telescope came online providing closure phase observations, allowing aperture synthesis imaging to be performed for the first time at IOTA. The array was decommissioned and disassembled in summer 2006 due to lack of funding.

Jesse L. Greenstein

Jesse Leonard Greenstein (October 15, 1909 – October 21, 2002) was an American astronomer. His parents were Maurice G. and Leah Feingold.

He earned a Ph.D, with thesis advisor Donald H. Menzel, from Harvard University in 1937, having started there at age 16. Before leaving Harvard, Greenstein was involved in a project with Fred Lawrence Whipple to explain Karl Jansky's discovery of radio waves from the Milky Way and to propose a source. He began his professional career at Yerkes Observatory under Otto Struve and later went to Caltech. With Louis G. Henyey he invented a new spectrograph and a wide-field camera. He directed the Caltech astronomy program until 1972 and later did classified work on military reconnaissance satellites.

With Leverett Davis, Jr, he demonstrated in 1949 that the magnetic field in our galaxy is aligned with the spiral arms. His theoretical work with Davis was based on the conclusion just reached by William A. Hiltner that the recently detected polarization of starlight was due to scattering off interstellar dust grains aligned by a magnetic field.

Greenstein did important work in determining the abundances of the elements in stars, and was, with Maarten Schmidt, among the first to recognize quasars as compact, very distant sources as bright as a galaxy. The spectra of the first quasars discovered, radio sources 3C 48 and 3C 273, were displaced so far to the red due to their redshifts as to be almost unrecognizable, but Greenstein deciphered 3C 48 shortly before Schmidt, his colleague at the Hale Observatories worked out the spectrum of 3C 273.

Loyal Blaine Aldrich

Loyal Blaine Aldrich (November 20, 1884 – February 11, 1965) was an American astrophysicist and astronomer of the Smithsonian Institution. Upon graduation from the University of Wisconsin in 1907, Aldrich became a Smithsonian Astrophysical Observatory assistant to Charles Greeley Abbot. The observatory conducted astrophysical research on solar radiation and the amount of energy from the sun that strikes the outer edge of the earth's atmosphere. Abbot became director of the observatory in 1907 and established solar observing stations in the United States, South America, and Africa to carry out research on solar radiation. Aldrich became director of the observatory from 1942 to 1955. Harvard University astronomy department chairman Fred Lawrence Whipple became director of the observatory when Aldrich retired.

MEarth Project

The MEarth Project is a United States NSF-funded, robotic observatory that is part of Fred Lawrence Whipple Observatory on Mt. Hopkins, Arizona, USA. The project monitors the brightness of thousands of red dwarf stars with the goal of finding transiting planets. As red dwarf stars are small, any transiting planet blocks a larger portion of starlight than transits around a Sun-like star would. This allows smaller planets to be detected through ground-based observations.

MEarth-NorthConsists of eight RC Optical Systems 40 cm (16 in) f/9 Ritchey-Chrétien telescopes consists of eight (on Paramount ME robotic mounts) paired with commercially available cameras with 2048 × 2048 Apogee U42 CCDs.

MEarth-SouthConsists of eight additional 40cm telescopes, each equipped with a CCD camera sensitive to red optical and near-infrared light. It observes from Cerro Tololo Inter-American Observatory, east of La Serena, Chile.


MINERVA-Australis is a forthcoming dedicated exoplanet observatory, under construction at the University of Southern Queensland, in Queensland, Australia. The facility is being built at USQ's Mt. Kent Observatory, with first light due in quarter two 2018.

The facility is based on, and being built in partnership with, the Miniature Exoplanet Radial Velocity Array (MINERVA), a northern hemisphere exoplanet facility located at the U.S. Fred Lawrence Whipple Observatory at Mt. Hopkins, Arizona. MINERVA-Australis is to be used to perform follow-up and characterisation observations of exoplanets discovered by the forthcoming Transiting Exoplanet Survey Satellite, TESS, which was launched in April, 2018.

The project's principal investigator is USQ astronomer Rob Wittenmyer.


MMT may refer to:

4QMMT (or MMT), one of the Dead Sea Scrolls that were discovered at Qumran in the West Bank

MMT Observatory, an astronomical observatory on the site of Fred Lawrence Whipple Observatory

MacMahon Master theorem, a result in enumerative combinatorics and linear algebra

MacroMedia Technologies, a large-scale digital sign printing and installation firm, based in the United States

Magical Mystery Tour, a 1967 double EP and LP by the English rock group The Beatles

McMaster Musical Theatre, one of two semi-professional acting companies at McMaster University

Medical massage therapy, a form of massage with outcome-based on healing treatment

Methadone maintenance treatment (MMT), the use of methadone for someone who is addicted to opioids

Methylcyclopentadienyl manganese tricarbonyl, an organomanganese compound with the formula (CH3C5H4)Mn(CO)3

Modern Monetary Theory, a branch of economic theory based in part on chartalism.

Montmorillonite, a naturally occurring clay found in volcanic ash and used in a variety of industrial and medical applications

MPEG media transport, a digital container format under development by the Moving Picture Experts Group

Multimode manual transmission, is a type of sequential manual transmission offered by Toyota

Myanmar Standard Time, the time zone used in Myanmar (UTC+6:30)

MMT Observatory

The MMT Observatory (MMTO) is an astronomical observatory on the site of Fred Lawrence Whipple Observatory (IAU observatory code 696). The Whipple observatory complex is located on Mount Hopkins, Arizona, US (55 km south of Tucson) in the Santa Rita Mountains. The observatory is run by the University of Arizona and the Smithsonian Institution, and has a visitor center in nearby Amado, Arizona.

The MMTO is the home of the MMT (formerly Multiple Mirror Telescope), which currently has a primary mirror 6.5 m in diameter. The name originally comes from the fact that the light gathering for the telescope was done by six smaller mirrors before the current primary mirror was installed. The current mirror has a special lightweight honeycomb design made by the University of Arizona's Steward Observatory Mirror Laboratory.

The MMT is housed in a building which allows the walls and roof around the telescope to be completely rolled back, allowing it to cool down very quickly in order to improve the seeing.

Man Will Conquer Space Soon!

"Man Will Conquer Space Soon!" was the title of a famous series of 1950s magazine articles in Collier's detailing Wernher von Braun's plans for manned spaceflight. Edited by Cornelius Ryan, the individual articles were authored by such space notables of the time as Willy Ley, Fred Lawrence Whipple, Dr. Joseph Kaplan, Dr. Heinz Haber, and von Braun. The articles were illustrated with paintings and drawings by Chesley Bonestell, Fred Freeman, and Rolf Klep, some of the finest magazine illustrators of the time.


A micrometeorite is essentially a micrometeoroid that has survived entry through Earth's atmosphere. The size of such a particle ranges from 50 µm to 2 mm. Usually found on Earth's surface, micrometeorites differ from meteorites in that they are smaller in size, more abundant, and different in composition. They are a subset of cosmic dust, which also includes the smaller interplanetary dust particles (IDPs).Micrometeorites enter Earth's atmosphere at high velocities (at least 11 km/s) and undergo heating through atmospheric friction and compression. Micrometeorites individually weigh between 10−9 and 10−4 g and collectively comprise most of the extraterrestrial material that has come to the present-day Earth.Fred Lawrence Whipple first coined the term "micro-meteorite" to describe dust-sized objects that fall to the Earth. Sometimes meteoroids and micrometeoroids entering the Earth's atmosphere are visible as meteors or "shooting stars", whether or not they reach the ground and survive as meteorites and micrometorites.

Miniature Exoplanet Radial Velocity Array

The MINiature Exoplanet Radial Velocity Array (MINERVA) is a ground-based robotic dedicated exoplanet observatory. The facility is an array of small-aperture robotic telescopes outfitted for both photometry and high-resolution Doppler spectroscopy located at the U.S. Fred Lawrence Whipple Observatory at Mt. Hopkins, Arizona. The project's principal investigator is the American astronomer John Johnson. The telescopes were manufactured by PlaneWave Instruments.

Mount Hopkins (Arizona)

Mount Hopkins is a 8,553-foot (2,607 m) peak of the Santa Rita Mountains range, in Santa Cruz County, southern Arizona.

The peak was named after Gilbert Hopkins, who was killed nearby during the Battle of Fort Buchanan in 1865.

It is in the Coronado National Forest and is bounded on three sides by the Mount Wrightson Wilderness.

Santa Rita Mountains

The Santa Rita Mountains (O'odham: To:wa Kuswo Doʼag), located about 65 km (40 mi) southeast of Tucson, Arizona, extend 42 km (26 mi) from north to south, then trending southeast. They merge again southeastwards into the Patagonia Mountains, trending northwest by southeast. The highest point in the range, and the highest point in the Tucson area, is Mount Wrightson, with an elevation of 9,453 feet (2,881 m), The range contains Madera Canyon, one of the world's premier birding areas. The Smithsonian Institution's Fred Lawrence Whipple Observatory is located on Mount Hopkins. The range is one of the Madrean sky islands.

The Santa Rita Mountains are mostly within the Coronado National Forest. Prior to 1908 they were the principal component of Santa Rita National Forest, which was combined with other small forest tracts to form Coronado. Much of the range is protected by the Mount Wrightson Wilderness. The Santa Rita Mountains were severely burned in July 2005 in the Florida Fire.

Other mountain ranges surrounding the Tucson valley include the Santa Catalina Mountains, the Rincon Mountains, the Tucson Mountains, and the Tortolita Mountains.

Upper Atmosphere Research Panel

The Upper Atmosphere Research Panel, also known as the V-2 Panel, was formed in 1946 to oversee experiments conducted using V-2 rockets brought to the United States after World War II. The experiments studied the upper atmosphere, solar radiation and X-ray astronomy, as well as the technology of the V-2 rocket.


VERITAS (Very Energetic Radiation Imaging Telescope Array System) is a major ground-based gamma-ray observatory with an array of four 12 meter optical reflectors for gamma-ray astronomy in the GeV – TeV photon energy range. VERITAS uses the Imaging Atmospheric Cherenkov Telescope technique to observe gamma-rays that cause particle showers in Earth's upper atmosphere. The telescope design is based on the design of the existing 10m gamma-ray telescope at the Fred Lawrence Whipple Observatory. It consists of an array of imaging telescopes deployed such that they permit the maximum versatility and give the highest sensitivity in the 50 GeV – 50 TeV band (with sensitivity from 100 GeV to over 10 TeV). This very high energy observatory, completed in 2007, effectively complements the Fermi Gamma-ray Space Telescope due to its large collection area as well as its higher energy bound.

Whipple (crater)

Whipple is a lunar impact crater located on the lunar far side near the northern pole. The crater is located East of the prominent craters Byrd and Peary; the latter of which it is located on the rim of.

Whipple is permanently shaded from the Sun. Volatile species of atoms and molecules, such as water (and mercury), that enter the crater freeze, and thus get trapped due to the extremely cold conditions that prevail within the crater. Moreover, Whipple crater's radar signature is characterized by a high, same-sense, circular-polarization ratio (CPR). This is thought to indicate that there are thick—at least 2 metres—ice deposits that are relatively pure. Such ice deposits represent a potentially valuable source of drinkable water, as well as rocket propellant in the form of liquid hydrogen and liquid oxygen (LH2/LO2).

In addition, Whipple is next to a large, quasi-permanently sunlit plateau that occupies its north rim. There, the sun is visible nearly 80% of the time on average; the temperature in such quasi-permanently sunlit areas is quite mild by Lunar standards, averaging approximately -50 °C, ± 10°. This combination of permanently shaded, high-CPR crater adjacent to quasi-permanently sunlit plateau is unique in the north polar region of the Moon.

Whipple was adopted and named after American astronomer Fred Lawrence Whipple by the IAU in 2009.

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