Guest Author - Lea Terry

Astronomer Percival Lowell is probably best known for his prediction of the existence of the planet Pluto. And though Pluto recently lost its planet status, this does not diminish Lowell’s contributions to astronomy.

Lowell was born March 13, 1855, in Boston, Mass., to the prominent Lowell family. His brother Abbot became president of Harvard University, and his sister Amy was a poet, critic and publisher. Percival, or “Percy,” Lowell, graduated with distinction from Harvard University in 1876, with a degree in mathematics. After college Lowell traveled extensively, writing several books on the cultures he encountered, particularly on Japan, in which he spent a great deal of time. It wasn’t until 1893 that Lowell decided to make astronomy his career, after reading Camille Flammarion’s book “La planete Mars,” and inspired by Giovanni Schiaparelli's discovery of “canals” on Mars. He built a private observatory at Flagstaff, Ariz., where he had moved in 1894, and which would be his home for the rest of his life. He wrote several books on his theories about Mars, which included his belief that an intelligent civilization had built the canals as Mars was dying. He argued that this civilization had constructed a planet-wide system of irrigation, using water from polar ice caps. These canals, he believed, were bands of vegetation. His beliefs received little support, however, and were disproved in July 1965, when the U.S. spacecraft Mariner 4 flew past the planet, and was able to relay more detailed observations.

In the early 1900s, Lowell began to devote his time to the search for “Planet X,” a then-unknown planet believed to exist beyond the orbit of Neptune. Astronomers had observed irregularities in predicted and observed positions of Neptune and Pluto, which they believed were caused by the gravitational influence of a nearby planet. Lowell made calculations predicting where this mystery planet might be, and though he didn’t find it, his calculations did lead to the discovery of a new celestial body in 1930, 14 years after his death. This body, named Pluto, was discovered by Clyde Tombaugh. However, it was soon realized that Pluto was too small to cause the irregularities noted--its position where Lowell had predicted was a seeming coincidence. In fact, it was later discovered that the irregularities noted were based on incorrect values for Neptune and Uranus. When the newer, more precise values are used, the irregularities vanish.

Lowell dedicated the last eight years of his life to the search for Planet X, and died on November 12, 1916. He was buried on Mars Hill, near Lowell Observatory.