Friday, March 13, 2009

March 13: Percival Lowell

Percival Lawrence Lowell
March 13, 1855 – November 12, 1916

Percival Lowell was a businessman, author, mathematician, and astronomer who fueled speculation that there were canals on Mars, founded the Lowell Observatory in Flagstaff, Arizona, and formed the beginning of the effort that led to the discovery of Pluto 14 years after his death. The choice of the name Pluto and its symbol were partly influenced by his initials PL.

Beginning in the winter of 1893-94, using his wealth and influence, Lowell dedicated himself to the study of astronomy, founding the observatory which bears his name. For the last 23 years of his life astronomy, the Lowell Observatory, and his and others' work at his observatory were the focal points of his life. He lived to be 61 years of age.

Lowell became determined to study Mars and astronomy as a full-time career after reading Camille Flammarion's La planète Mars. He was particularly interested in the canals of Mars, as drawn by Italian astronomer Giovanni Schiaparelli, who was director of the Milan Observatory. In 1894 Lowell chose Flagstaff, Arizona Territory as the home of his new observatory. At an altitude of over 2,100 meters (7,000 feet), with few cloudy nights, and far from city lights, Flagstaff was an excellent site for astronomical observations. This marked the first time an observatory had been deliberately located in a remote, elevated place for optimal seeing.

For the next fifteen years he studied Mars extensively, and made intricate drawings of the surface markings as he perceived them. Lowell published his views in three books: Mars (1895), Mars and Its Canals (1906), and Mars As the Abode of Life (1908). With these writings, Lowell more than anyone else popularized the long-held belief that these markings showed that Mars sustained intelligent life forms. While this idea excited the public, the astronomical community was skeptical. Many astronomers could not see these markings, and few believed that they were as extensive as Lowell claimed. As a result, Lowell and his observatory were largely ostracized. Although the consensus was that some actual features did exist which would account for these markings.

In 1909 the sixty-inch Mount Wilson Observatory telescope in Southern California allowed closer observation of the structures Lowell had interpreted as canals, and revealed irregular geological features, probably the result of natural erosion.
The existence of canal-like features would not be definitively disproved until Mariner 4 took the first close-up pictures of Mars in 1965, and Mariner 9 orbited and mapped the planet in 1972. Today, the surface markings taken to be canals are regarded as an optical illusion.

Lowell's greatest contribution to planetary studies came during the last decade of his life, which he devoted to the search for Planet X, a hypothetical planet beyond Neptune. Lowell believed that the planets Uranus and Neptune were displaced from their predicted positions by the gravity of the unseen Planet X. Although Lowell's searches from 1905 to 1916 proved unsuccessful, the search continued after his death at Flagstaff in 1916.

In 1930, Clyde Tombaugh, a young astronomer recently hired by the Lowell Observatory, discovered the planet, named Pluto. Partly in recognition of Lowell's efforts, a stylized P-L monogram (the first two letters of the new planet's name and also Lowell's initials), was chosen as Pluto's astronomical symbol.

However, it would subsequently emerge that the Planet X theory was mistaken.
Pluto's mass could not be determined until 1978, when a satellite was discovered. This confirmed what had been increasingly suspected: Pluto's gravitational influence on Uranus and Neptune is negligible, certainly not nearly enough to account for the discrepancies in their orbits. In 2006, after Clyde Tombaugh's death, Pluto was reclassified as a dwarf planet by the International Astronomical Union.

In addition, it is now known that the discrepancies between the predicted and observed positions of Uranus and Neptune were not caused by the gravity of an unknown planet. Rather, they were due to an erroneous value for the mass of Neptune. Voyager 2's 1989 encounter with Neptune yielded a more precise value of its mass, and the discrepancies disappear when using this value.

Although Lowell's theories of the Martian canals and of Planet X are now discredited, his practice of building observatories at the position where they would best function has been adopted as a principle. He also established the program and setting which made the discovery of Pluto by Clyde Tombaugh possible.

The Lunar crater Lowell and a crater on Mars have been named in his honor.


  1. The controversial reclassification of Pluto was done by only four percent of the IAU, most of whom are not planetary scientists, and was immediately rejected by hundreds of professional astronomers led by Dr. Alan Stern, Principal Investigator of NASA's New Horizons mission to Pluto. One of the reasons the reclassification makes no sense is that it states that dwarf planets are not planets at all, which runs counter to the use of the term "dwarf" in astronomy, where dwarf stars are still stars, and dwarf galaxies are still galaxies. For this reason, the IAU vote should be reported not as fact but as one interpretation, alongside a note that it is not accepted by many professional astronomers, some of whom are either working to overturn the demotion or are ignoring it altogether.

  2. Ah, the Pluto Girl found me!
    If you hadn't left a comment I was going to put a link on your FB wall.