Short version: It's open-source, open data (export/import allowed) and has a much cooler zoomable map. Plus it can tell you how much you still need to fly to get to Mars.
Long version: http://openflights.org/faq
In Soviet ISS, it seems, computers reboot YOU!The failure occurred in computers on the Russian segment of the 16-nation space station — computers that control navigation and critical life-support systems on the huge orbital base. Without them, the station cannot maintain proper orbit and the crew cannot stay on board.
Machines take me by surprise with great frequency. - Alan Turing