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Asaph Hall
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Asaph Hall III (October 15, 1829 – November 22, 1907) was an American astronomer who is best known for having discovered the two moons of Mars, Deimos and Phobos, in 1877.[1] He determined the orbits of satellites of other planets and of double stars, the rotation of Saturn, and the mass of Mars.

Key Information

Biography

[edit]

Hall was born in Goshen, Connecticut, the son of Asaph Hall II (1800–42), a clockmaker, and Hannah Palmer (1804–80). His paternal grandfather Asaph Hall I (June 11, 1735 – March 29, 1800) was a Revolutionary War officer and Connecticut state legislator.[2][3] His father died when he was 13, leaving the family in financial difficulty, so Hall left school at 16 to become an apprentice to a carpenter. He later enrolled at the New-York Central College in McGrawville, New York, where he studied mathematics. There he took classes from an instructor of geometry and German, Angeline Stickney. In 1856 they married.

In 1856, Hall took a job at the Harvard College Observatory in Cambridge, Massachusetts, and turned out to be an expert computer of orbits. Hall became assistant astronomer at the US Naval Observatory in Washington, D.C. in 1862, and within a year of his arrival he was made professor.

On June 5, 1872 Hall published an article entitled "On an experimental determination of " in the journal Messenger of Mathematics.[4] In this article, Hall reported the results of an experiment in random sampling that Hall had persuaded his friend, Captain O.C. Fox, to perform when Fox was recuperating from a wound received at the Second Battle of Bull Run. The experiment involved repetitively throwing at random a fine steel wire onto a plane wooden surface ruled with equidistant parallel lines. An approximation of was then computed as , where is the number of trials, is the length of the steel wire, is the distance between parallel lines, and is the number of intersections. This paper, an experiment on Buffon's needle problem, is a very early documented use of random sampling (which Nicholas Metropolis would name the Monte Carlo method during the Manhattan Project of World War II) in scientific inquiry.

In 1875 Hall was given responsibility for the USNO 26-inch (66-cm) telescope, the largest refracting telescope in the world at the time. It was with this telescope that he discovered Phobos and Deimos in August 1877. Hall also noticed a white spot on Saturn which he used as a marker to ascertain the planet's rotational period. In 1884, Hall showed that the position of the elliptical orbit of Saturn's moon, Hyperion, was retrograding by about 20° per year. Hall also investigated stellar parallaxes and the positions of the stars in the Pleiades star cluster.

Hall was responsible for apprenticing Henry S. Pritchett at the Naval Observatory in 1875.

Discovery of Phobos and Deimos

[edit]

During Mars's closest approach in 1877, Hall was encouraged by Angeline Stickney, his wife, to search for the Martian moons. His calculations had shown that the orbit should be very close to the planet. Hall wrote "The chance of finding a satellite appeared to be very slight, so that I might have abandoned the search had it not been for the encouragement of my wife."[5]

Asaph Hall discovered Deimos on August 12, 1877 at about 07:48 UTC and Phobos on August 18, 1877, at the US Naval Observatory in Washington, D.C., at about 09:14 GMT (contemporary sources, using the pre-1925 astronomical convention that began the day at noon, give the time of discovery as 11 August 14:40 and 17 August 16:06 Washington mean time respectively).[6][7][8] At the time, he was deliberately searching for Martian moons. Hall had previously seen what appeared to be a Martian moon on August 10, but due to bad weather, he could not definitively identify them until later.

Hall recorded his discovery of Phobos in his notebook as follows:[9]

The telescope used to discover the Martian moons
"I repeated the examination in the early part of the night of 11th [August 1877], and again found nothing, but trying again some hours later I found a faint object on the following side and a little north of the planet. I had barely time to secure an observation of its position when fog from the River stopped the work. This was at half past two o'clock on the night of the 11th. Cloudy weather intervened for several days.
"On 15 August the weather looking more promising, I slept at the Observatory. The sky cleared off with a thunderstorm at 11 o'clock and the search was resumed. The atmosphere however was in a very bad condition and Mars was so blazing and unsteady that nothing could be seen of the object, which we now know was at that time so near the planet as to be invisible.
"On 16 August the object was found again on the following side of the planet, and the observations of that night showed that it was moving with the planet, and if a satellite, was near one of its elongations. Until this time I had said nothing to anyone at the Observatory of my search for a satellite of Mars, but on leaving the observatory after these observations of the 16th, at about three o'clock in the morning, I told my assistant, George Anderson, to whom I had shown the object, that I thought I had discovered a satellite of Mars. I told him also to keep quiet as I did not wish anything said until the matter was beyond doubt. He said nothing, but the thing was too good to keep and I let it out myself. On 17 August between one and two o'clock, while I was reducing my observations, Professor Newcomb came into my room to eat his lunch and I showed him my measures of the faint object near Mars which proved that it was moving with the planet.
"On 17 August while waiting and watching for the outer moon, the inner one was discovered. The observations of the 17th and 18th put beyond doubt the character of these objects and the discovery was publicly announced by Admiral Rodgers."
Hall's former home in the Georgetown neighborhood of Washington, D.C., after enlargement. Note Angeline on front steps and two workers.

Hall retired from the Navy in 1891. He became a lecturer in celestial mechanics at Harvard University in 1896, and continued to teach there until 1901.

Family

[edit]

The Halls had four children. Asaph Hall, Jr. (1859–1930) became an astronomer, Samuel Stickney Hall (1864–1936) worked for Mutual Life Insurance Company, Angelo Hall (1868–1922) became a Unitarian minister and professor of mathematics at the US Naval Academy, and Percival Hall (1872–1953) became president of Gallaudet University. Angeline Hall died in 1892. Hall married Mary Gauthier after he fully retired to Goshen, Connecticut in 1901.

Hall died in November 1907 while visiting his son Angelo in Annapolis, Maryland.

Awards and honors

[edit]
Hall's Gold Medal of the Royal Astronomical Society

Hall was elected as a member to the American Philosophical Society in 1878.[10] He won the Lalande Prize of the French Academy of Sciences in 1878, the Gold Medal of the Royal Astronomical Society in 1879, the Arago Medal in 1893, and was made a Chevalier in the Ordre national de la Légion d'honneur (French Legion of Honor) in 1896.[11] In 1885, he was President of the Philosophical Society of Washington.[12] Hall crater on the Moon as well as Hall crater on the Martian moon Phobos[13] are named in his honor.

References

[edit]

Further reading

[edit]
[edit]
Revisions and contributorsEdit on WikipediaRead on Wikipedia

Asaph Hall

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Asaph Hall (October 15, 1829 – November 22, 1907) was an American astronomer renowned for discovering the two moons of Mars, Phobos and Deimos, in August 1877 using the 26-inch Alvan Clark refractor telescope at the U.S. Naval Observatory. Born in , to a clockmaker father, Hall overcame early hardships following his father's death at age 13 by working as a carpenter and supporting his family through farming and crafting wooden molds for cheese production. Largely self-taught in astronomy, he pursued informal studies at institutions including Central College in McGrawville, New York, the , and Harvard's Lawrence Scientific School, where he honed his skills in and without earning a formal degree. Hall's professional career began in 1857 as an assistant at the Harvard College Observatory, where he computed orbits and refined his observational expertise. In 1862, he joined the U.S. Naval Observatory in Washington, D.C., as an assistant astronomer, rising to Professor of Mathematics in 1863 and eventually overseeing the observatory's premier instruments. During his tenure, which lasted until his retirement in 1891, Hall conducted extensive research on planetary perturbations, double stars, stellar parallaxes, and the satellites of outer planets; notable among these were his 1864–1870 catalog of 151 stars in the Praesepe cluster and his 1876–1877 measurement of Saturn's rotation period using a transient white spot on the planet. His most celebrated achievement came amid the 1877 close opposition of Mars, when, after initial cloudy nights, he first spotted Deimos on August 11 (confirmed August 12) and Phobos on August 17, naming them after the mythological attendants of Ares (Mars) to reflect their diminutive size and rapid orbits. Post-retirement, Hall returned to Harvard in 1896 as an instructor in astronomy and , continuing his scholarly work until 1901. His contributions earned him prestigious honors, including election to the in 1875, the Royal Astronomical Society's Gold Medal in 1879, the Lalande Prize in 1878, the Arago Medal in 1893, and honorary degrees from Harvard and Yale. Hall's legacy endures in astronomical nomenclature, with a lunar and a on Phobos bearing his name, underscoring his pivotal role in advancing our understanding of the solar system. He died in , after a second marriage in 1901 following the passing of his first , Angeline Stickney, with whom he had five children.

Early Life and Education

Birth and Childhood

Asaph Hall was born on October 15, 1829, in , into a family of modest means engaged in farming and . His father, Asaph Hall II (1800–1842), worked as a , while his mother, Hannah Palmer Hall (1804–1880), managed the household; the family resided in the rural Hart Hollow section of town, where Hall's grandfather had settled in 1758 and later served in the Revolutionary War under . Hall's early years were shaped by the rugged landscape of northwestern , a region of grassy hills and limited opportunities that instilled a strong sense of from a young age. He grew up assisting with farm chores in the family's encumbered property near Ivy Mountain, an environment that emphasized practical labor over formal pursuits, though he attended the local district school intermittently and explored his father's collection of books on various subjects. The death of his father on September 6, 1842, during a clock-selling trip to , Georgia, plunged the family into financial hardship when Hall was 12 years old, leaving his mother to raise six children, including Hall as the eldest son. To support the household, Hall took on farm work and odd jobs, including tasks such as constructing wooden molds for local cheesemaker Lewis Norton's pineapple cheeses, which highlighted his emerging aptitude for mechanics and manual precision. These formative experiences in Hart Hollow cultivated Hall's resourcefulness and hands-on skills with tools and measurements, qualities that would later prove invaluable in his astronomical computations despite the era's rudimentary resources.

Formal Education and Self-Study

Hall's formal education began in the local district schools of , where he received basic instruction during his early years. At around age 16, he attended for one winter term, focusing on algebra and the first six books of under the principal's guidance, which laid a strong foundation in . In the summer of 1854, Hall enrolled at Central College in McGrawville, New York, for approximately one and a half years, studying , French, and Latin while supporting himself through work repairing college buildings. There, as a senior student assisting in instruction, Angeline Stickney—whom he would marry in 1856—taught him and German, fostering his interest in rigorous, precise calculations essential for astronomical pursuits. After moving to following his marriage, Hall entered Harvard's Lawrence Scientific School in 1857, attending lectures by Professor while beginning work at the Observatory. Financial constraints limited Hall's access to higher education, but he pursued self-study voraciously, drawing from his father's library to read historical works by and Hume, which broadened his intellectual habits. He advanced in independently, tackling topics like algebra and infinitesimal through texts such as Euler's Introductio ad Analysin Infinitorum. To access advanced resources, in 1856 he traveled 15 miles to the Western Reserve College library in , to study excerpts from Laplace's Mécanique Céleste. In early 1856, Hall entered the sophomore class at the in Ann Arbor, taking informal classes in French under L.A. Fasquelle and in astronomy basics under Professor Franz Brünnow, including hands-on work with instruments for about three months. Unable to continue due to funds, he returned home but maintained correspondence with Brünnow for guidance on further studies. Following his marriage, Hall accelerated his self-study of German, learning 30 to 40 words daily from his wife in 1857–1858 to read original mathematical and astronomical works in the language.

Professional Career

Early Positions at Observatories

Asaph Hall began his professional career in astronomy in August 1857, when he was appointed as an assistant at the Harvard College Observatory in Cambridge, Massachusetts. Initially supervised by William Cranch Bond, the observatory's director, Hall earned a modest salary of $3 per week for the first six months, which was later increased to $4 per week and then to $400 annually following Bond's death in 1859, under the direction of George Phillips Bond. This entry-level position marked Hall's transition from self-study to paid work in the field, where he supported the observatory's ongoing projects amid limited funding. Hall's duties at Harvard primarily involved routine astronomical computations, including the determination of orbits for comets and small , as well as observations such as moon culminations and contributions to almanac preparations. For instance, he computed the of a discovered in and published the results in the Astronomical Journal, demonstrating his growing proficiency. These tasks, which encompassed both observational and calculational work on the transit circle and zone catalogs, allowed Hall to develop substantial expertise in , laying the groundwork for his future contributions to orbital analysis. In 1862, Hall resigned from Harvard to accept a position at the USNO, attracted by the higher salary and better prospects amid the Civil War. In August 1862, Hall secured an appointment as assistant astronomer at the United States Naval Observatory (USNO) in Washington, D.C., after successfully passing a competitive examination; the position offered a salary of $1,000 per year, significantly higher than his Harvard earnings. Shortly after his arrival, amid the Civil War's intensity, Hall had the opportunity to demonstrate celestial objects through the observatory's equatorial telescope to President Abraham Lincoln and Secretary of War Edwin Stanton; Lincoln later returned alone for a private discussion on astronomical principles. This encounter highlighted the observatory's role in wartime Washington and marked Hall's integration into a more prominent institution.

Roles at the US Naval Observatory

Asaph Hall joined the (USNO) in , as an assistant astronomer in 1862, shortly after authorized additional positions to expand the observatory's staff. In the spring of 1863, following the resignation of Professor , Hall was promoted to professor of mathematics, a rank he held for the remainder of his naval career; this advancement recognized his mathematical expertise and placed him among the observatory's senior scientific officers. In this role, Hall oversaw observations, which were essential for determining precise astronomical positions and supporting the USNO's critical function of timekeeping for the U.S. Navy, including the distribution of time signals via telegraph to naval vessels and stations. Hall's responsibilities expanded to include the of advanced observational instruments. From 1864 to 1870, he directed a major project using the to compile a catalog of stars in the Praesepe cluster, contributing to fundamental astronomical data reduction. In 1873, the USNO installed the 26-inch Alvan G. refracting , then the largest refractor in the world, at a cost of over $46,000; Hall took charge of its operations by May 1875 and used it extensively for stellar and planetary observations until his retirement. Prior to that, from 1868 to 1875, he managed the observatory's smaller equatorial telescope, building expertise in high-precision visual astronomy. Throughout his tenure, Hall performed routine yet meticulous astronomical duties that advanced both naval and scientific objectives. He conducted systematic observations of double stars, measuring over 1,600 such systems in a single year by 1880 using the equatorial instruments, which helped refine and orbital parameters. Hall also observed occultations, such as the notable 1868 event involving , to verify and positional accuracy. Additionally, he contributed to determinations of astronomical constants, including —the subtle wobble in Earth's axis—through long-term meridian and transit circle measurements that improved navigational ephemerides. After nearly 30 years of service, Hall retired from the USNO on October 15, 1891, upon reaching the age of 62, in accordance with naval regulations for professors of . His departure marked the end of an era at the observatory, where his leadership in instrumentation and observations had solidified the USNO's reputation for rigorous .

Astronomical Discoveries and Contributions

Discovery of Phobos and Deimos

In August 1877, Mars reached a particularly close opposition to , appearing larger and brighter in the sky than usual and providing astronomers with an ideal window to search for any potential satellites orbiting the planet. Asaph Hall, a of at the , undertook this systematic search using the observatory's newly commissioned 26-inch , the largest of its kind at the time, which offered unprecedented resolution for detecting faint objects near the planet's glare. Hall first sighted the outer satellite, later named Deimos, on August 11, 1877 (confirmed August 12), after several nights of fruitless efforts hampered by the moons' extreme faintness—both are irregular, potato-shaped bodies only a few kilometers across—and the overwhelming brightness of Mars itself. Poor weather conditions, including fog and clouds, frequently interrupted observations, adding to the frustration of distinguishing the tiny objects from stars or instrumental artifacts. On August 17, 1877, Hall detected the inner satellite, Phobos, closer to Mars and even more challenging to observe due to its rapid orbital motion, completing a revolution every 7.6 hours. Nearly ready to abandon the effort after repeated failures, Hall was encouraged by his wife, Angeline Stickney Hall, a who urged him to continue despite the setbacks; her persistence proved pivotal in maintaining his resolve during those critical August nights. To confirm the discoveries, Hall promptly computed preliminary for both bodies, demonstrating their independent motion around Mars rather than fixed stellar positions, thus verifying them as natural satellites. The names Phobos ("fear") and Deimos ("terror") were selected from , representing the sons of (the Greek equivalent of Mars), at the suggestion of Henry Madan; this choice echoed the fictional mention of two small Martian moons in Jonathan Swift's 1726 satirical novel , which had long intrigued astronomers despite lacking empirical basis.

Other Works in Astronomy

Throughout his career, Asaph Hall made significant contributions to through meticulous calculations of orbits for comets, planets, and satellites. He computed orbital elements for several comets, including Comet I of 1862 and Encke's Comet in 1871, publishing these in Astronomische Nachrichten (volumes 58 and 79, respectively). Similarly, Hall determined orbits for minor planets such as (66) Maja in 1862 and revised elements for asteroid (124) Alceste between 1873 and 1874, also in Astronomische Nachrichten (volumes 82 and 84). These works demonstrated his expertise in refining ephemerides to improve predictive accuracy for astronomical observations. Hall's research on Saturn was particularly extensive, focusing on its rings and inner satellites. He conducted precise observations and calculations for the orbits of Saturn's satellites, including Hyperion in 1884 and Iapetus from 1884 to 1890, detailed in Washington Observations. In his comprehensive publication Saturn and Its Ring, 1875-1889, Hall described detailed views of the planet's ring system, including the Cassini Division—a prominent gap in the rings visible at the south pole of the planet during certain orientations—and noted its indistinct appearance under varying atmospheric conditions. Additionally, he observed a prominent white spot on Saturn in 1876–1877, using it to determine the planet's equatorial rotation period of approximately 10 hours, 14 minutes, and 24 seconds, as reported in Astronomische Nachrichten (volume 90). These efforts advanced understanding of Saturn's complex ring dynamics and satellite motions. In stellar astronomy, Hall contributed to the study of orbits and measurements. He published over 1,614 observations of in 1880, highlighting limitations in the instruments used at the U.S. Naval Observatory, as documented in Washington Observations (Appendix VI). For , Hall measured the distances of key stars, including α Lyrae and in 1882, deriving values and incorporating temperature coefficients for meridian observations; these results appeared in Washington Observations (Appendix II) and proceedings of the American Association for the Advancement of Science. His work provided refined estimates of stellar distances, aiding in galactic structure studies. Hall also advanced fundamental astronomy through investigations of planetary perturbations and related constants. He analyzed secular perturbations of the major planets in 1870 (American Journal of Science, volume 50) and specific cases like the perturbations of (8) Flora by Mars in (Astronomical Journal, volume 13) and (147) Nemausa by in 1895 (Astronomical Journal, volume 16). Regarding the constant of aberration—a key parameter in positional astronomy—Hall determined its value from meridian observations in the , publishing in Washington Observations and Astronomical Journal (volume 8, 1888–1889). These studies refined models of Earth's motion and planetary interactions. Finally, Hall's publications on occultations and eclipse predictions underscored his role in predictive astronomy. He observed the occultation of by the in 1868 (Washington Observations, page 327) and documented multiple lunar occultations in 1871 (Washington Observations, pages 103–116). For eclipses, Hall reported on solar events, including the 1869 in , the 1870 in , and the 1878 in , all in Washington Observations. These observations and predictions supported nautical almanacs and enhanced timing precision for global astronomical events.

Personal Life

Family and Marriages

Asaph Hall married Chloe Angeline Stickney, a mathematics teacher he met while studying at New York Central College, on March 31, 1856, in Elkhorn, Wisconsin. She had tutored him in geometry and German, fostering his early mathematical skills and passion for astronomy despite his limited formal education. Angeline played a pivotal role in supporting Hall's career, accompanying him on relocations such as their 1857 move to Cambridge, Massachusetts, with only $50 in savings to join the Harvard College Observatory, and their 1862 relocation to Washington, D.C., where Hall began work at the U.S. Naval Observatory. Angeline's encouragement proved instrumental during challenging periods, including her motivation for Hall to continue observing Mars in despite initial frustrations, which led to his discovery of its moons, Phobos and Deimos. She sacrificed her own teaching career after marriage due to social norms but remained deeply involved in family life and Hall's professional pursuits, often assisting with computations and managing household demands amid financial strains. Angeline died in July 1892 after 36 years of marriage. Hall and Angeline had four sons, born between 1859 and 1875: Asaph Hall Jr., who followed in his father's footsteps as an astronomer at the Harvard College Observatory and U.S. Naval Observatory; Samuel Stickney Hall; Angelo Hall; and Percival Hall, who became president of , a leading institution for the deaf. The family's stability enabled Hall's demanding observatory roles, with Angeline handling domestic responsibilities during frequent night observations and career shifts, while the children grew up immersed in an environment that emphasized scientific and educational pursuits, influencing their own professional paths in academia and related fields. Following Angeline's death, Hall remarried Mary B. Gauthier, a longtime family acquaintance, in the autumn of 1901 after his retirement. The couple settled at Hall's rural home in , where she provided companionship in his later years.

Later Years and Death

After retiring from the U.S. Naval Observatory in 1891, Hall accepted an invitation to serve as a lecturer in astronomy at from 1896 to 1901, where he taught courses in to advanced students. In 1901, Hall fully retired from professional duties and returned to his hometown of , spending his remaining years in relative seclusion with family. His second wife, Mary Bertha Gauthier, whom he had married in 1901, accompanied him during this period, and the couple focused on personal life away from public observatories. Public engagements were minimal, allowing Hall to reflect on his career amid the comforts of home and family. Hall died on November 22, 1907, at the age of 78, while visiting his son, Professor Angelo Hall, in . His body was returned to Goshen for burial in the family on November 25, a private ceremony attended by immediate relatives who honored his lifelong dedication to astronomy through simple tributes at the graveside.

Legacy

Awards and Recognitions

Asaph Hall received several prestigious awards for his contributions to astronomy, particularly his 1877 discovery of the , Phobos and Deimos. He was elected to the in 1875. In 1877, he was awarded the Lalande Prize by the in recognition of this breakthrough, which advanced understanding of the Martian system. In 1878, Hall was elected as a member of the , honoring his growing influence in American scientific circles. He received honorary Doctor of Laws (LL.D.) degrees from in 1879 and in 1886. In 1879, the Royal Astronomical Society presented Hall with its for his discovery of the Martian satellites and his subsequent precise orbital calculations, which provided critical data on their paths. Later in his career, Hall's broader astronomical achievements were acknowledged with the Arago Medal from the in 1893, celebrating his lifelong work in . In 1896, he was appointed Chevalier of the Legion of Honor by the French government, a distinction for his enduring impact on international astronomy.

Named Features and Enduring Influence

The International Astronomical Union (IAU) has honored Asaph Hall by naming two craters after him: one on the far side of the Moon and another on Phobos, the larger moon of Mars that Hall himself discovered. The lunar crater Hall, located in the northeastern quadrant near the Lacus Somniorum, measures approximately 35 kilometers in diameter and commemorates his contributions to astronomy. Similarly, the Phobos crater Hall, situated on the satellite's irregular surface, reflects his pivotal role in identifying and characterizing Martian moons. These namings, approved through the IAU's planetary nomenclature process managed in collaboration with the U.S. Geological Survey, ensure Hall's legacy endures in the mapping of celestial bodies. A personal dimension to this tribute appears in the naming of Stickney Crater, the largest impact feature on Phobos at about 9 kilometers across—nearly half the moon's diameter—which honors Hall's first wife, Chloe Angeline Stickney Hall (1830–1892). Angeline, a who encouraged Hall during his 1877 search for Martian satellites, is credited by him for the breakthrough; the crater's name links her intellectual support to his professional achievements, as formalized by the IAU. This feature, imaged prominently by NASA's Viking orbiters in the , highlights the intertwined personal and scientific aspects of Hall's legacy. Hall's precise calculations of the orbits of Phobos and Deimos laid foundational work for satellite astronomy, influencing subsequent Mars exploration efforts. His 1878 ephemerides and enabled accurate predictions that supported planning for later missions, including NASA's (1975–1976), which imaged the moons up close, and the Mars Exploration Rovers (2003–2012), which relied on refined models derived from early observations like Hall's to navigate Martian space. These computations remain relevant in for small body dynamics around Mars. Hall's family extended his influence across astronomy and education. His son, Asaph Hall Jr. (1853–1936), pursued a career in astronomy, earning a doctorate from Yale in 1889 and contributing publications on comet orbits, such as the 1907 elements and ephemerides of planet 1907 XP, while serving at the U.S. Naval Observatory and later the University of Michigan's Detroit Observatory. Another son, Percival Hall (1872–1953), became a leader in deaf education as president of Gallaudet University from 1910 to 1945, advocating for sign language integration in curricula and expanding academic programs. Hall's methods in celestial mechanics, including his work on satellite perturbations, continue to be referenced in modern textbooks on orbital theory, underscoring their enduring pedagogical value.

References

  1. https://www.lindahall.org/about/news/scientist-of-the-day/asaph-hall/
  2. http://biographicalmemoirs.org/pdfs/hall-asaph.pdf
  3. https://connecticuthistory.org/goshens-asaph-hall-becomes-an-astronomical-success/
  4. https://www.astronomy.com/today-in-the-history-of-astronomy/aug-11-1877-asaph-hall-discovers-deimos/
  5. https://en.wikisource.org/wiki/Popular_Science_Monthly/Volume_45/October_1894/Sketch_of_Asaph_Hall
  6. https://www.gutenberg.org/files/58553/58553-h/58553-h.htm
  7. https://vvovisitors.wesleyan.edu/astronomers/person/27
  8. https://www.cnmoc.usff.navy.mil/Our-Commands/United-States-Naval-Observatory/Frequently-Asked-Questions-about-the-USNO/Command-History-of-the-US-Naval-Observatory/
  9. https://www.cnmoc.usff.navy.mil/Our-Commands/United-States-Naval-Observatory/Our-Telescopes/The-26-inch-Great-Equatorial-telescope/
  10. https://ui.adsabs.harvard.edu/abs/2025AAS...24510002B/abstract
  11. https://science.nasa.gov/mars/moons/facts/
  12. https://www.nps.gov/parkhistory/online_books/butowsky5/astro4g.htm
  13. https://science.nasa.gov/mars/moons/deimos/
  14. https://science.nasa.gov/mars/moons/phobos/
  15. https://adsabs.harvard.edu/full/1878USNOM..15D...1H
  16. https://aas.org/posts/story/2016/07/month-astronomical-history-moons-mars
  17. https://adsabs.harvard.edu/full/1891USNOO...3B...1H
  18. https://www.astronomy.com/today-in-the-history-of-astronomy/aug-17-1877-asaph-hall-discovers-phobos/
  19. https://westphaliapress.org/2023/02/25/an-astronomers-wife-the-biography-of-angeline-hall/
  20. https://kids.kiddle.co/Asaph_Hall
  21. https://www.encyclopedia.com/people/science-and-technology/astronomy-biographies/asaph-hall
  22. https://www.ams.org/journals/bull/1896-02-08/S0002-9904-1896-00348-7/S0002-9904-1896-00348-7.pdf
  23. https://www.registercitizen.com/news/article/Historian-holds-birthday-celebration-for-Goshen-15654107.php
  24. https://adsabs.harvard.edu/full/1908PA.....16...67P
  25. https://www.nature.com/articles/017271a0
  26. https://www.amphilsoc.org/sites/default/files/2020-12/attachments/members_list_2019.pdf
  27. https://academic.oup.com/mnras/article/39/4/306/995422
  28. https://link.springer.com/article/10.1007/s11214-025-01165-7
  29. https://sites.lsa.umich.edu/astrohistory/2015/03/13/asaph-hall-jr/
  30. https://gallaudet.edu/archives/archives-collections/presidential-papers-collection/presidential-papers-percival-hall-1910-1945/
  31. https://adsabs.harvard.edu/full/1992ComAp..16...17H
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