He organized an expedition to Santiago de Chile to observe the Venus transit the Sun in 1882. A second Belgian expedition (led by Jean-Charles Houzeau) travelled to San Antonio, Texas to determine the planet's parallax during the same transit. Both parties used a specially designed heliometer for this purpose.
A crater on Mars was named in his honor.
- Description of the 1882 transit of Venus expeditions
- Mars globe presented by Louis Niesten to the Royal Astronomical Society
|This article about a Belgian scientist is a stub. You can help Wikipedia by expanding it.|
|This European astronomer-related article is a stub. You can help Wikipedia by expanding it.|