In people with chronic myelogenous leukemia, the chromosomes in the blood cells swap sections with each other. A section of chromosome 9 switches places with a section of chromosome 22, creating an extra-short chromosome 22 and an extra-long chromosome 9.
Discovered on September 23, 1846, by John Couch Adams. Neptune was the first planet found by mathematical prediction rather than by observation. Unexpected changes in the orbit of Uranus led astronomers to deduce that its orbit was subject to gravitational perturbation by an unknown planet.
A notable recent find was discovering seasons on the moon, using the European Southern Observatory's Very Large Telescope in Chile. Discovery and flyby. Triton was found on Oct. 10, 1846, just 17 days after Neptune was discovered. According to NASA, Triton was known simply as  the satellite of Neptune  until 1949, when a second moon (Nereid) was found.