1. The problem statement, all variables and given/known data You land on an unknown planet. The first night you note that its celestial pole is 40 degrees above the northern horizon at your current position. Your flight module is able to go 1000 km/hour. You fly an hour due south, and note that the celestial pole is now 30 degrees above the horizon. How big is the planet? 2. Relevant equations Circle Circumference Formula 3. The attempt at a solution What I started off with was that we travelled 10 degrees in 1 hour, right? That means 10 degrees of the planet as a "circle" is 1000km. Using this, we can calculate the circumference as 1000km * 36, right? Am I on the right track? Thank you.