Planet Nine estimated mass of ten Earths, a diameter two to four times that of Earth, and an elongated orbit lasting 10,000 - 20,000 years. Batygin and Brown suggest that Planet Nine could be the core of a primordial giant planet that was ejected from its original orbit by Jupiter during the genesis of the Solar System. Others have proposed that the planet was captured from another star, is a captured rogue planet, or that it formed on a distant orbit and was pulled into an eccentric orbit by a passing star. As of 2018, efforts have failed to directly observe Planet
The 50 Most Extreme Places in Our Solar System Press Book for Public and Secondary School Libraries by the Association of American University Presses. The 50 Most Extreme Places in Our Solar System The 50 Most Extreme Places in Our Solar System is the title of a science book by David Baker, professor of physics at Austin College and Todd Ratcliff, a planetary geophysicist at the Jet Propulsion Laboratory. The book is divided into nine sections with a few chapters in each section. The divisions are roughly phenomenological. The book is currently available in two translations with a third in progress. Reviews have been positive including being awarded Honorable