Transit of Phobos from Mars north of 70.4°N; for some days in the year, its shadow misses the surface entirely and falls north or south of Mars. At any given geographical location on the surface of Mars, there are two intervals in a Martian year when the shadow of Phobos or Deimos is passing through its latitude. During each such interval, about half a dozen transits of Phobos can be seen by observers at that geographical location (compared to zero or one transits of Deimos). Transits of Phobos happen during Martian autumn and winter in the respective hemisphere; close to the equator they happen around
Mars One all the research, supplier Lockheed Martin says that the technologies were viable. Another serious concern uncovered in the research conducted by MIT is replacement parts. The PhD candidates estimated the need for spare parts in a Mars colony based on the failure rates of parts on the ISS. They determined that a resupply mission every two years would be necessary unless a large space in the initial launch were to be reserved for extra materials. Lansdorp commented on this saying, "They are correct. The major challenge of Mars One is keeping everything up and running. We don't believe what we