A second object like Sedna, known as 2012 VP113, was announced by Trujillo and Shepherd in 2014. (sciencedaily.com)
Isotope analyses showed that while the first fall had separated from its parent body about 3 million years ago, the second object became detached about 50 million years ago. (newscientist.com)
Only when a second object was introduced into a tank, a simulated fish, did the model begin to twitch significantly. (sciencemag.org)