For the record, the planet is estimated to have started taking shape about 50,000 to 100,000 years ago, but also for the record it's the youngest planet ever observed. The previous record holder was about five times older.
The planet is formally known as LkCa 15 b. The discovery was presented this week at NASA's Goddard Space Flight Center in Maryland. The research is due to appear in the next issue of The Astrophysical Journal.