Jérôme Lalande facts for kids
Quick facts for kids
Jérôme Lalande
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Jérôme de La Lande by Jean-Honoré Fragonard, c. 1769
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| Born | 11 July 1732 |
| Died | 4 April 1807 (aged 74) Paris
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| Nationality | French |
| Children | 1 |
| Scientific career | |
| Fields | Astronomy |
| Institutions | Paris observatory |
| Doctoral advisor | Joseph-Nicolas Delisle Pierre Charles Le Monnier |
| Doctoral students | Jean Baptiste Joseph Delambre |
Joseph Jérôme Lefrançois de Lalande (born July 11, 1732 – died April 4, 1807) was a famous French astronomer and writer. He made important contributions to understanding the planets and popularizing astronomy.
Contents
Early Life and Studies
Jérôme Lalande was born in Bourg-en-Bresse, France. His parents sent him to Paris to study law. However, he lived in a place called Hôtel Cluny, which was near an observatory run by Joseph-Nicolas Delisle. This sparked his interest in astronomy.
Lalande became a dedicated student of both Delisle and Pierre Charles Le Monnier. After finishing his law studies, he was about to go back home. But Le Monnier arranged for him to go to Berlin. There, Lalande helped observe the lunar parallax. This was done with Nicolas Louis de Lacaille who was observing from the Cape of Good Hope. Measuring the lunar parallax helps scientists figure out the distance to the Moon.
Becoming a Famous Astronomer
Lalande did a great job with his observations in Berlin. Because of this, he was accepted into the Prussian Academy of Sciences before he was even 21 years old. He was also chosen as an astronomer for the French Academy of Sciences.
He then focused on improving how we understand the planets. In 1759, he published an updated version of Edmond Halley's tables. These tables included a history of Halley's Comet. Lalande also helped Alexis Clairaut and Nicole-Reine Lepaute calculate when the comet would return that year.
In 1762, Delisle gave his astronomy teaching position at the Collège de France to Lalande. Lalande held this position for 46 years. His home became a place where many future astronomers learned. Some of his students included Jean Baptiste Joseph Delambre, Giuseppe Piazzi, and Pierre Méchain.
Lalande became very famous for his work on the transit of Venus in 1769. A transit of Venus is when Venus passes directly between the Sun and Earth, appearing as a small black dot moving across the Sun's face.
Other Contributions and Legacy
In 1766, Lalande helped start a group in Paris called "Les Sciences." Later, in 1776, he changed its name to Les Neuf Soeurs. He also helped arrange for Benjamin Franklin to become its first leader.
Lalande worked very hard to popularize astronomy. He was a great lecturer and writer. His tables of planetary positions were the best available until the end of the 1700s. These tables included corrections for how planets pull on each other with gravity.
In 1801, he created the Lalande Prize. This award is given by the French Academy of Sciences for important advances in astronomy. Pierre-Antoine Véron, a young astronomer who was the first to measure the size of the Pacific Ocean from east to west, was one of Lalande's students.
Lalande never married. He had a student named Marie-Jeanne de Lalande who was very good at mathematics and helped him with his work.
Almost Discovering Neptune
In February 1847, Sears C. Walker from the US Naval Observatory was looking through old records. He was searching for any earlier sightings of the planet Neptune, which had just been discovered the year before.
He found that observations made by Lalande's team in 1795 were in the same part of the sky where Neptune would have been. On May 8 and May 10, 1795, a "star" was observed and recorded. There was a note of uncertainty about its position. At first, this note could have meant an observing error. But after looking at the original records, it became clear that the object was Neptune. The slight difference in position between the two nights was due to the planet moving across the sky.
Finding these old records of Neptune's position from 1795 helped scientists calculate the planet's orbit even better.
Awards and Recognition
- In 1765, Lalande became a member of the Royal Swedish Academy of Sciences.
- In 1781, he was chosen as an Honorary Member of the American Academy of Arts and Sciences.
- His name is one of the 72 names written on the Eiffel Tower in Paris.
- A crater on the Moon is named Lalande after him.
- A high school in Bourg-en-Bresse, his hometown, is named after Lalande. This school received a special award, the Médaille de la Résistance, for the brave actions of its teachers and students during wartime.
Notable Works
Lalande wrote many important books and papers, including:
- Traité d'astronomie (Treatise on Astronomy), a major work on astronomy.
- Histoire céleste française (French Celestial History), which listed the positions of 47,390 stars.
- Bibliographie astronomique (Astronomical Bibliography), a history of astronomy from 1780 to 1802.
- Astronomie des dames (Astronomy for Ladies), a book to help women learn about astronomy.
- Abrégé de navigation (Summary of Navigation), a guide for sailors.
- Voyage d'un françois en Italie (Journey of a Frenchman in Italy), a valuable record of his travels in 1765–1766.
- Journal d'un voyage en Angleterre (Diary of a Trip to England).
He also wrote more than 150 papers for the French Academy of Sciences. He edited the Connoissance de temps (a yearly astronomical almanac) for many years. He also wrote the last two volumes of Jean-Étienne Montucla's Histoire des mathématiques (History of Mathematics).
See also
- Lalande 21185
- Les Neuf Sœurs
- Felis (constellation)
- Quadrans Muralis
- Atlas Coelestis
- Officina Typographica
