Researchers at the Oregon State University found out that those who continue to work after retiring tend to live longer, in spite of other factors such as lifestyle and health issues.
Dolly Varden, an Alaskan trout species, are able to retire from migrating each year after growing big enough to store and utilize fat reserves. This is the only known species that partakes in such a retirement.
On March 18, 2011, NASA's MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) spacecraft finally inserted itself into orbit around Mercury after six and a half years of traveling across our solar system. Now the 11-year-old spacecraft is finally retiring, with plans to end its career by leaving its mark on the planet it observed for so long.